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Chapter 7. Organometallic compounds of the transition elements

 

作者: J. D. Jones,  

 

期刊: Annual Reports Section "B" (Organic Chemistry)  (RSC Available online 1973)
卷期: Volume 70, issue 1  

页码: 243-267

 

ISSN:0069-3030

 

年代: 1973

 

DOI:10.1039/OC9737000243

 

出版商: RSC

 

数据来源: RSC

 

摘要:

7 Organometallic Compounds of the Transition Elements By J. D. JONES R. PEARCE and G. L. P. RANDALL lCl Ltd. Corporate Laboratory P.O. Box 1 I The Heath Runcorn WA7 4QE 1 Introduction We have adopted approximately the same format as in previous years with emphasis being given to modification and transformation of organic compounds by organometallic complexes of the transition metals and to the mechanisms of the more important catalytic reactions. The reader’s attention is drawn to the fact that those aspects of catalytic processes that involve either stereoselective synthesis or the transformation of homogeneous catalysts into a form that is readily separable from the product mixture (heterogenized) are dealt with in separate sections. 2 Reviews Areas of chemistry involving organometallic transition-metal complexes that have been reviewed include :homogeneous hydrogenation ‘y2 hydrosilyla-asymmetric ~ynthesis,~ ti~n,~ cyclo-oligomerization,5 atmospheric pressure carboxylation,6 skeletal isomerization,7 heterocyclic synthesis,* the role of carbene complexes as reaction intermediate^,^ synthetic applications of metal 7r-allyl~,’~ ‘the nickel effect’,’ CO insertion,’ organocobalt compounds,’ ’ B.R. James ‘Homogeneous Hydrogenation’ Wiley New York 1973. ’R. E. Harmon S. K. Gupta and D. J. Brown Chem. Rev. 1973,73 21. C. S. Cundy B. M. Kingston and M. F. Lappert .4dv. Organometallic Chem. 1973 11 253. B. Bogdanovic Angew. Chem. Internat. Edn. 1973 12 954. P. Heimbach Angew. Chem. Internat.Edn. 1973 12 975. L. Cassar G. P. Chiusoli and F. Geurrieri Synthesis 1973 509. ’J. R. Anderson Adv. in Catalysis 1973 23 I. C. W. Bird J. Organometallic Chem. 1973 47 281. B. Cetinkaya D. J. Cardin M. J. Doyle and M. F. Lappert Chem. Soc. Rev. 1973 2,99. lo R. Baker Chem. Rev. 1973 73 487. ‘I K. Fischer K. Jonas P. Misbach R. Stabba and G. Wilke Angew. Chem. Internat. Edn. 1973 12 943. I’ A. Wojcicki Adv. Organometallic Chem. 1973 11 88. l3 D. Dodd and M. D. Johnson J. Organometallic Chem. 1973 52 I ;H. Bonnemann Angew. Chem. Internat. Edn. 1973 12 964; Gmelins Handbuch der Anorganischen Chemie Verlag Chemie 1973. 243 244 J. D. Jones R. Pearce and G. L. P. Randall palladium and platinum ~hemistry,'~ the role of palladium in addition reactions of butadiene,' exchange and isomerization'6 and aromatic substitution of olefins," metal-induced carbonium ions in platinum complexes,18 r-ligand tran~fer,'~ mass spectrometry,20 organometallic electrochemistry,2' and stability and reactivity of metal alkyls.22 3 Organometallic Complexes a-Complexes.-The chemistry of o-hydrocarbyls especially of the binary com- plexes is an expanding area.Contributions this year may be placed in three categories (i) new complexes including R3M,2THF (R = Me3CCH or Me,SiCH,; M = Scor Y),23(Me3SiCH2),TaCl -,,(n = 2or 3),24(Me,SiCH2C~)t5 with a novel square-planar arrangement of copper atoms with singly bridging CH2-/ alkyls,26 and phosphorous ylide complexes based on the bidentate Me2P \ CH2-(R) R2M2 (M = Cu Ag or Au),~' R,Ni2,28 and R,Cr;29 (ii) full details of previously reported complexes including silylmethyls and neopentyls of Ti Zr and Hf,,' Nb Ta Cr and Mo,,l Me6W,32 ArAg and Ar2AgLi (Ar = e.g.o-M~,NCH,C,H,-),~~ and R Ri-,TiLi ;34 (iii) Studies of decomposition l4 F. R. Hartley 'The Chemistry of Platinum and Palladium' Applied Science London 1973. J. Tsuji Accounts Chem. Res. 1973 6 8. I6 P. M. Henry Accounts Chem. Res. 1973 6 16. " I. Moritani and Y. Fujiwara Synthesis 1973 524. M. H. Chisholm and H. C. Clark Accounts Chem. Res. 1973 6 202. l9 A. Efraty J. Organometallic Chem. 1973 57 I. 2o M. R. Litzow and T. R. Spalding 'Mass Spectrometry of Inorganic and Organometallic Compounds' Elsevier Amsterdam 1973.2' H. Lehmkuhl Synthesis 1973 377. 22 P. S. Braterman and R. J. Cross Chem. SOC.Rev. 1973 2 271 ;F. Calderazzo Pure Appl. Chem. 1973,33,453. 23 M. F. Lappert and R. Pearce J.C.S. Chem. Comm. 1973 126. 24 S. Moorhouse and G. Wilkinson J. Organometallic Chem. 1973 52 C5. 25 M. F. Lappert and R. Pearce J.C.S. Chem. Comm. 1973 24. 26 J. A. J. Jarvis B. T. Kilbourn R. Pearce and M. F. Lappert J.C.S. Chem. Comm. 1973,475. 27 H. Schmidbaur J. Adlkofer and W. Buchner Angew. Chem. Internat. Edn. 1973 12 415; H. Schmidbaur and R. Franke ibid. p. 416. 2R H. H. Karsch and H. Schmidbaur Angew. Chem. Internat. Edn. 1973 12 853. 29 E. Kurras U. Rosenthal H. Mennenga and G. Oehme Angew. Chem. Internat. Edn. 1973 12 854. 30 M. R. Collier M. F. Lappert and R.Pearce J.C.S. Dalton 1973 445; P. J. Davidson M. F. Lappert and R.Pearce J. Organomerallic Chem. 1973 57 269. W. Mowat and G. Wilkinson J.C.S. Dalton 1973 1120; W. Mowat A. J. Shortland N. J. Hill and G. Wilkinson ihid. p. 770. 32 A. J. Shortland and G. Wilkinson J.C.S. Dalton 1973 872. " A. J. Leusink G. van Koten J. W. Marsman and J. G. Noltes J. Organometallic Chem. 1973 55 419; A. J. Leusink G. van Koten and J. G. Noltes ibid. 1973 56 379. " J. Muller H. Rau P. Zdunneck and K.-H. Thiele Z. anorg. Chem. 1973,401 113. Organometallic Compounds of the Transition Elements 245 pathways particularly P-and reductive elimination in complexes e.g. (PhCH,),-Zr,,' (Ph,P),RhR,36 R'R2R3AuPR3 ,37 (Ph3P)2Pt(CH2),,38 and (Ph,P),Pt(I)- Me,.39 The observation that addition of aluminium alkyls accelerates the decomposi- tion of transition-metal hydrocarbyls points to the need for extreme care in the preparation of these complexes if meaningful data are to be obtained and also to the possible function of aluminium compounds in Ziegler catalysis in labilizing a metal-carbon bond.40 New methods of M-C synthesis include (i) interaction (with subsequent metallation) of phosphorous ylides with metal halides ;27728 (ii) halogen-alkyl exchange involving alkyls of Sn,,l Zn,24 Hg,4' and Ag42 where competing side reactions with RLi are avoided and partial alkylation may be achieved; (iii) direct synthesis from metal vapour and aryl halides ;43 and from carbocation sources e.g.MeS0,F (giving novel cationic metal alkyl~).~~ A recently discovered synthetic method that is now becoming accepted by organic chemists and has been successfully applied to the synthesis of e.g.prostaglandins juvenile hormones and pheromones is the formation of carbon- carbon bonds by organocopper reagents usually of the type R,CuLi. The anion in these reagents has considerably reduced nucleophilic character compared with that in lithium or magnesium reagents permitting their use in reactions with compounds containing carbonyl groups where attack at this function is much suppressed and avoiding some other side reactions associated with organo- lithiums. Their use in synthesis has been re~iewed.~' The two main areas of application are in (i) coupling e.g. with alkyl/aryl halides acid halides a-halo- genoketones and tosylates ;46 (ii) addition to unsaturated systems e.g.cis-addition to acetylenic compounds to give specifically substituted ole fin^,,^ and conjugate addition to aP-unsaturated carbonyl compounds.48 35 K.-H. Thiele E. Kohler and B. Adler J. Organometallic Chem. 1973 50 153. 36 C. S. Cundy M. F. Lappert and R. Pearce J. Organometallic Chem. 1973 59 161. 37 A. Tamaki S. A. Magennis and J. K. Kochi J. Amer. Chem. SOC. 1973 95 6487; A. Tamaki and J. K. Kochi J. Organometallic Chem. 1973 61 441; J.C.S. Chem. Comm. 1973,423. 38 J. X. McDermott J. F. White and G. M. Whitesides J. Amer. Chem. SOC. 1973 95 445 1. " M. P. Brown R. J. Puddephatt and C. E. E. Upton J. Organometallic Chem. 1973 49 C61. 40 T. Yamamoto and A.Yamamoto J. Organometallic Chem. 1973 57 127. 41 C. Santini-Scampucci and J. G. Riess J.C.S. Dalton 1973 2436; C. J. Cardin D. J. Cardin M. F. Lappert and K. W. Muir J. Organometa/lic Chem. 1973 60 C70. 42 R. L. Bennett M. I. Bruce and R. C. F. Gardner J.C.S. Dalton 1973 2653. 43 K. J. Klabunde and J. Y. F. Low J. Organometallic Chem. 1973 51 C33. 44 J. L. Peterson T. E. Nappier jun. and D. W. Meek J. Amer. Chem. SOC. 1973 95 8195; D. Strope and D. F. Shriver ibid. p. 8197. 45 J. F. Normant Synthesis 1972 63; G. H. Posner Org. Reactions 1972 19 1. C. R. Johnson and G. A. Dutra J. Amer. Chem. Soc. 1973 95 7777 7783; G. H. Posner and J. J. Sterling ibid. p. 3076. S. B. Bowlas and J. A. Katzenellenbogen Tetrahedron Letters 1973 1277; J. F. Normant G.Cahiez C. Chuit and J. Villieras ibid. p. 2407; J. Organometallic Chem. 1973 54 c53. 48 E. J. Corey and R. H. K. Chen Tetrahedron Letters 1973 1611; P. A. Grieco and R. Finkelhar J. Org. Chem. 1973 38 2100. 246 J. D. Jones R. Pearce and G. L. P. Randall Two important extensions of this work are the increase in the range of R groups that may be used to include secondary and tertiary alkyl groups and the increase in yield with respect to the amount of R converted into product this latter aspect being important in synthesis of complex molecules. These objectives have been achieved with reagents of the type RCUXL~,~~ readily prepared from RLi and CuX where X is eg. Bu‘C=C CN Bu‘O PhS. Varying X affects the thermal stability of the reagent its solubility in the reaction medium and its selectivity in reaction PhS appearing to be the most versatile.While organocopper species do not react readily with carbonyl group^,^^'^^ the use of these reagents in the derivatization of aldehydes and ketones to tertiary and quaternary carbon centres has been investigated. Reactions studied include those with p-alkoxy and thioalkoxy ab-unsaturated carbonyl corn pound^,^ readily prepared from 1,3-diketones and with ab-ethylenic sulphur corn pound^.^^ n-Complexes.-Simple olefin complexes have now been prepared. Both tris- (ethylene)nickel obtained from C2H and all-trans-1,5,9-~yclododecatriene-nickel(^),^^ and tris(norb0rnene)nickel are reasonably stable the latter having an approximately trigonal planar arrangement of the olefinic units around nickel.54 (Z-c&I&Ti has been prepared by condensation of benzene and titanium vapour at 77 K ; a symmetrical sandwich structure was propo~ed.’~ Variable-temperature ‘H and ’3C n.m.r.measurements on Os(CO)NO(C,H,)- (PPh,),PF have allowed an assignment of the mode of rotation of the olefin within the ~omplex.’~ The rotation axis is that of the metalhlefin bond and not the carbon-carbon double bond. Fluxional behaviour was also found in the analogous acetylene complex but the data did not allow an assignment in this case.57 Further insight has been gained into the structure of the elusive titanocene in some structural studies on cycldpentadienyl complexes of Ti Nb and Mo.~~ These show that the unit C5H4 is a general feature being found as a bridging ligand and as the fulvalene ligand (see also ref.59). 49 G. H. Posner C. E. Whitten and J. J. Sterling J. Amer. Chem. Soc. 1973 95 7788; H. 0.House and M. J. Umen J. Org. Chem. 1973 38 3893; J.-P. Gorlier L. Hamon J. Levisalles and J. Wagnon J.C.S. Chem. Comm. 1973 88; G. H. Posner and C. E. Whitten Tetrahedron Letters 1973 1815. 50 CJ L. T. Scott and W. P. Cotton J.C.S. Chem. Comm. 1973 320. ” G. H. Posner and D. J. Brunelle J.C.S. Chem. Comm. 1973 907; C. P. Casey D. F. Marten and R. A. Boggs Tetrahedron Letters 1973 2071. ’’ G. H. Posner and D. J. Brunelle Tetrahedron Letters 1973 935; J. Org. Chem. 1973 38 2747. ’3 K. Fischer K. Jonas and G. Wilke Angew. Chem. Internat. Edn. 1973 12 565. 54 C.Kruger B. L. Barnett D. J. Brauer and Y.-H. Tsay Ah. Sixth Internat. Con$ Organometallic Chem. 1973 80. 55 F. W. S. Benfield M. L. H. Green J. S. Ogden and D. Young J.C.S. Chem. Comm. 1973 866. 56 B. F. G. Johnson and J. A. Segal J.C.S. Chem. Comm. 1973 1312. ” J. Ashley-Smith B. F. G. Johnson and J. A. Segal J. Organometallic Chem. 1973 49 C38. 58 L. J. Guggenberger and F. N. Tebbe J. Amer. Chem. Soc. 1973,95,7870; J.C.S. Chem. Comm. 1973 227; L. J. Guggenberger Inorg. Chem. 1973 12 294; R. A. Forder M. L. H. Green R. E. Mackenzie J. S. Poland and K. Prout J.C.S. Chem. Comm. 1973 426. An improved synthesis of fulvalene complexes of the late transition metals is described in A. Davison and J. C. Smart J. Organometallic Chem. 1973 49 C43. Organometallic Compounds of the Transition Elements 247 Carbene Complexes.-The carbene group in metal complexes is generally un- reactive but a number of papers have reported possible uses in organic synthesis.These involve carbene transfer to silanes a method complementing the halo- alkylmercury route ;60 reactions of anions generated CI to the carbene carbon ;61 and coupling with the carbenoid fragment in diazo alkanes and phosphorous ylides.62 Evidence has been presented for the intermediacy of carbene complexes in metal-catalysed addition of amines to isocyanides to give for ma mi dine^.^^ A new departure is in the preparation of complexes of the other Group IVB element^,^^,^' e.g. stannylenes as in [(Me,Si),CH]2SnCr(CO),.64 Reactions of Group I11 metal-carbenes have given two novel complexes reaction of (OC),-WC(0Me)R with BX gives the carbyne complexes RC=W(CO)4X66 and reaction of (OC),CrC(OMe)Ph with diazabicyclo[2,2,2]octane gives the N-ylide (q.67 /F77 (CO)5CrC-,OMe N \ WN Ph 4 Hydrogenation The subject has now reached a state of maturity with papers addressing them- selves more to an understanding of the workings of existing systems than to the reporting of new catalysts.A problem in catalysis not restricted to hydrogena- tion is that the concentration of the reactive species (usually produced by neutral ligand dissociation) that participate in the catalytic cycle is usually small e.g. the equilibrium RuH,(PPh,) @ RuH,(PPh,) + PPh lies well to the left. The new apparently simple technique of reverse osmosis offers a solution.By a suitable choice of membrane free phosphine may be removed to give the reactive RuH,(PPh,), and to illustrate the utility of the technique the authors also report the isolation of new complexes by this method.68 6o J. A. Connor P. D. Rose and R. M. Turner J. Organomerallic Chem. 1973 55 11 1. 6' C. P. Casey R. A. Boggs and R. L. Anderson J. Amer. Chem. SOC., 1972,94 8947. 62 C. P. Casey S. H. Bertz and T. J. Burkhardt Tetrahedron Letters 1973 1421. 63 J. A. McCleverty and M. M. M. da Mota J.C.S. Dalton 1973 2571; J. E. Parks and A. L. Balch J. Organometaffic Chem. 1973 57 C103. 64 P. J. Davidson and M. F. Lappert J.C.S. Chem. Comm. 1973 317. 65 T. J. Marks and A. R. Newman J. Amer.Chem. SOC. 1973,95 769; M. D. Brice and F. A. Cotton ibid. p. 4529. 66 E. 0. Fischer G. Kreis C. G. Kreiter J. Muller G. Huttner and H. Lorenz Angew. Chem. Internat. Edn. 1973 12 564. '' F. R. Kreissl E. 0.Fischer C. G. Kreiter and K. Weiss Angew. Chem. Internat. Edn. 1973 12 563. 68 L. W. Gosser W. H. Knoth and G. W. Parshall J. Amer. Chem. SOC.,1973.95 3436. 248 J. D.Jones R. Pearce and G. L. P. Randall Both (Ph,P),RhCl and (Ph,P),Rh,CI are lo4 times less reactive towards H2 than (Ph,P),RhCl. (Ph,P),Rh,CI now appears to be of no significance in the mechanistic scheme for hydr~genation.~~ Earlier assumptions on the reversibility of H uptake by the (Ph,P),RhCl system are now shown to be invalid. In both C6H6 and CHC1,-EtOH solvents H uptake was irreversible the kinetically non-labile (Ph,P),RhHCl being identified in the latter system.70 Stereochemical criteria for mechanistic studies have been proposed wherein the variation of the isomeric ratio of the hydrogenation products of 4-t-butyl- methylenecyclohexane with H pressure may allow an assignment of the rate- determining step in the catalytic cycle.For (Ph,P),RhCI it is the formation of the hydridoalkyl from the olefin complex whereas at high H pressure for HRh(CO)(PPh,) it is the formation of the olefin complex.71 The importance of the solvent in determining reaction mechanism is brought out in a study of Co(CN) - where in glycerol-methanol a radical mechanism prevails whereas in water organocobalt species are involved.72 Other complexes studied include (7c-C5H,),MoH ,73 Mn2(C0),o,74 (Ph,P),Fe(N,)H ,75 (n-areneRuCl,) ,76 (Ph,P),Ru(CO)CI ,77 (P~,P),Ru,+,~~ (Ph,P),OsH and (Ph,P),OsH ,79 CO(CN),~-," (Ph,P),CoH(N) with NaCloH,,81 (Ph,P),M(NO) (M = Co Rh or Ir),* Rh,(OAc) ,83 (Ph,P),RhC1,84 (py),RhCI,-NaBH ,85 H,Ir(CO)-(PPh,) ,86 (Ph,P),Ir(CO)C1,87 and (cyclo-octene),Ir2C1 .88 The high-boiling solvent technique using the system PtC1,-Et,NMCl (M = Ge or Sn) offers a useful alternative to techniques employing either polymer- supported catalysts or product separation using selective membranes.1,5,9-Cyclododecatriene was selectively hydrogenated to cycl~dodecene~~ (see also ref. 90). Selective hydrogenation of both orb-unsaturated carbonyl and nitrile compounds has been achieved using Rh6(CO) 6-CO-H,0,91 while addition 69 J.Halpern and C. S. Wong J.C.S. Chem. Comm. 1973 629. 70 G. G. Strathdee and R. M. Given J. Catalysis 1973 30 30. S. Siege1 and D. W. Ohrt Tetrahedron Letters 1972 5 155. 72 T. Funabiki M. Mohri and K. Tarama J.C.S. Dalton 1973 1813. 73 A. Nakamara and S. Otsuka J. Amer. Chem. SOC. 1973,957262; Tetrahedron Letters 1973 4529. 74 T. A. Weil S. Meltin and I. Wender J. Organometallic Chem. 1973 49 227. 75 E. Koerner von Gustorf I. Fischler J. Leitich and H. Dreeskamp Angew. Chem. Internat. Edn. 1972 11 1088. l6 A. G. Hinze Rec. Trav. chim. 1973,92 542; R. Iwata and I. Ogata Tetrahedron 1973 29 2753. 77 D. R. Fahey J. Org. Chem. 1973 38 3343. 7H R. W. Mitchell A. Spencer and G. Wilkinson J.C.S. Dalton 1973 846.79 B. Bell J. Chatt and G. J. Leigh J.C.S. Dalton 1973 997. 8o J. Basters C. J. Groenenboom H. van Bekkum and L. L. van Reijen Rec. Trav. chim. 1973 92 219. S. Tyrlik J. Organometallic Chem. 1973 50 C46. 82 G. Dolcetti Inorg. Nuclear Chem. Letters 1973 9 705. 83 B. C. Y. Hui W. K. Teo and G. L. Rempel Inorg. Chem. 1973 12 757. " B.Bayeri M. Wahren and J. Graefe Tetrahedron 1973 29 1837. 85 C. J. Love and F. J. McQuillin J.C.S. Perkin I 1973 2509. 86 M. G. Burnett and R. J. Morrison J.C.S. Dalton 1973 632. M. G. Burnett R. J. Morrison and C. J. Strugnell J.C.S. Dalton 1973 701. 8H C. Y. Chan and B. R. James Inorg. Nuclear Chem. Letters 1973,9 135. 89 G. W. Parshall J. Amer. Chem. SOC. 1972 94 8716. 90 D. H. Fahey J. Org. Chem. 1973 38 80.91 T. Kitamura N. Sakamoto and T. Joh Chem. Letters 1973 379. Organometallic Compounds of the Transition Elements 249 of base to (Ph,P),RuCl allows greater selectivity in the hydrogenation of a number of steroids such that the method now appears synthetically useful.92 Interestingly (Ph,P),Ir(CO)Cl selectively hydrogenates 1,3- and 1,4-cyclohex- adiene to cyclohexene without competing isomerization or disprop~rtionation.'~ Not strictly within the scope of hydrogenation are a number of potentially useful reductions involving transition-metal complexes e.g. reduction of enones by (X-C,H,),F~-HC~,~~ of cyclic acid anhydrides to aldehyde acids by Na2- Fe(C0)4,95 and selective reduction of the functions -C=CX (X = OAc C1 or CHO) to -C=CH and AcO-C-C=O to H-C-C=O by Fe(CO) .96 5 Hydrosilylation Hydrosilylation of unsaturated functions containing heteroatoms (e.g.C=O C=N) is a method that complements hydrogenation in organic synthesis e.g. R2 R2 I 0 R' / \c/ OSiX II \ /c //o XW* C/ -R'CH2CHR2CR3 c c RICH, I I 1 H R3 R3 This year significant contributions have been made in this area using Rh and Pd complexes particularly (Ph,P),R hC1 as homogeneous catalysts. Hydrosilyla- tion of ap-unsaturated terpene carbonyl compounds is said to be the most selective method for reduction in these systems with predominantly 1,4-addition and without isomerization or hydrogenation of other areas of unsaturation within the rn01ecule.~' Stereoselective reduction of terpene ketones was also in~estigated.~~ Enamines and isocyanates are readily hydrosilylated to give ~ilylamines~~ and N-silylformamidines loo respectively which may be further transformed by cleavage (e.g.with MeCOCl) of the Si-N bond.Contrary to earlier findings nickel compounds [e.g.(Ph,P),NiCl,] are now found to be effective in the hydrosilylation of olefins. They are operative above ca. 90 "C and show similar reactivity to the Pt complexes."' With the silanes R,SiH ,some unusual products arising via SiH-SIC1 exchange were obtained.lo2 92 S. Nishimura T. Ichino A. Akimoto and K. Tsuneda Bull. Chern. SOC.Japan 1973 46 279. 93 J. E. Lyons J. Catalysis 1973 30 490. 94 K. Yamakawa and M. Moroe J. Organometallic Chern. 1973 50 C43. 95 Y. Watanabe M. Yamashita T.Mitsudo M. Tanaka and Y. Takegami Tetrahedron Letters 1973 3535. 96 S. J. Nelson G. Detre and M. Tanabe Tetrahedron Letters 1973 447. 97 I. Ojima and T. Kogure Tetrahedron Letters 1972 5035. 98 I. Ojima M. Nihonyanagi and Y. Nagai Bull Chern. Sor. Japan 1972.45 3722. 99 I. Ojima T. Kogure and Y. Nagai Tetrahedron Letters 1973 2475. I00 I. Ojima and S. Inaba Tetrahedron Letters 1973 4363. I01 Y. Kiso M. Kumada K. Tamao and M. Umeno J. Organornetallic Chern. 1973 50 297. I02 Y. Kiso M. Kumada. K. Maeda K. Sumitani and K. Tamao J. Organornetallic Chem. 1973 50 3 1 1. J. D. Jones R. Pearce and G. L. P. Randall (Ph,P),NiCl also catalyses the addition of R,SiH2 to dienes to give 1,4- products by both Si-H and surprisingly Si-Si addition and to acetylenes to give silacyclopentadienes.'O3 Silenoid intermediates are proposed (cf. ref. 104). Selective hydrosilylation of styrene by (Cp)Ni(CO) to give l-silylphenyl- ethanes has been rep~rted,"~ and a chelating carbaboranyldiphosphine nickel complex gives an unusually high proportion of the internal product in hydrosilyla- tion of cr-oIefins.lo6 A new departure in this field is in the use of Ziegler-Natta catalysts. Differ- ences from the conventional Group VIII catalysts were found the most notable being the production of the 2:l adduct H,C=CRC(R)=CHSiX with acety- lenes. O7 (Ph,P),RhCl has been used as a catalyst for the related reaction of dehydro- genative condensation of silanes with alcohols. The reaction is surprisingly not complicated either by disproportionation of silane or by isomerization and/or hydrogenation (by the produced H2) of other functions in the molecule.lo8 6 Metal-catalysed Hydrogen Exchange Progress this year was essentially confined to mechanistic aspects.Platinum catalysts continue to be studied.'09-' l3 Attempts have been made without success to exploit the activation of saturated hydrocarbons by Pt" by diverting the possible hydridoalkyl or platinum-alkene intermediates into pathways other than that leading to simple H/D exchange. The authors concluded that the correlation of reactivity in the H/D exchange reaction already noted is an index of the polarizability of the C-H bonqs within the molecule and that H/D exchange is probably a synchronous process the reactive Pt species being of the type DPtC12+.lo9 On the other hand proof of the formation of Pt-alkyl intermediates in this reaction has been claimed from a study of the reaction of Pt" complexes with alkylmercury compounds under the H/D exchange con- ditions.' '' Application of a microwave spectroscopic technique to H/D ex- change in propene points to a mechanism involving metal hydride addition- elimination rather than the formation of n-ally1 species by allylic C-H oxidative addition.' l4 Io3 H.Okinoshima K. Yamamoto and M. Kumada J. Amer. Chem. SOC. 1972 94 9263. I. Ojima S. Inaba T. Kogure and Y. Nagai J. Organometallic Chem. 1973 55 C7. lo' P. Svoboda P. Sedlmayer and J. Hetflejs Coll. Czech. Chem. Comm. 1973 38 1783.'06 M. Kumada K. Sumitani Y. Kiso and K. Tamao J. Organometallic Chem. 1973 50 3 19. lo' M. F. Lappert and S. Takahashi J.C.S. Chem. Comm. 1972 1272. Io8 I. Ojima T. Kogure M. Nihonyanagi H. Kono and S. Inaba Chem. Letters 1973 501 ; R. J. P. Corriu and J. J. E. Moreau J.C.S. Chem. Comm. 1973 38. Io9 G. W. Littlecott and F. J. McQuillin Tetrahedron Letters 1973 5013. 'lo N. F. Gol'dshleger I. I. Moiseev M. L. Khidekel and A. A. Shteinman Proc. Acad. Sci. U.S.S.R. 1972 206 694. R. J. Hodges D. E. Webster and P. B. Wells J.C.S. Dalton 1972 2571 2577. G. E. Calf and J. L. Garnett Tetrahedron Letters 1973 51 1. C. Masters J.C.S. Chem. Comm. 1972 1258; 1973 191. Il4 C. A. Tolman and L. H. Scharpen J.C.S. Dalton 1973 584. Organometallic Compoundsof the Transition Elements 25 1 (Ph,P),R hC1 catalyses the hydrogen transfer from dioxan to cyclopentene with the formation of cyclopentane and dioxene.The rate-determining step was reasonably assigned to the activation of the C-H bond of dioxan by oxida- tive addition to Rh.' l5 Full details of hydrocarbon activation by (Cp),MH (M = Nb or Ta) have now appeared.' ' 7 Oxidative Addition and Reductive Elimination Further evidence has appeared regarding the free-radical nature of oxidative addition reactions e.s.r. spectroscopic evidence is offered to show that the formally two-electron oxidation of Pto to Pt" by addition of alkyl halide proceeds in discrete one-electron steps involving free-radical intermediates. ''' A number of publications deal with the process of reductive elimination free-radicals are generated under mild conditions by the reaction of diethyl fumarate with dialkyl Pt" complexes,' and deuteriation studies indicate that the reductive elimination of ethane from (Me,PPh),PtMe,I proceeds via a first-order intra- molecular reaction' ' while the cis-elimination of ethane from EtMe,Au"'(PPh,) proceeds via initial phosphine dissociation.' 2o However it is also reported that the elimination of ethane from cationic dimethyl Au" complexes is favoured by co-ordination of bulky phosphine ligands,' and elimination from trimethyl Pt" cations is favoured if two of the three accompanying ligands are of high trans-influence.'22 A number of organic syntheses involving oxidative addition to and reductive elimination from transition metals have been reported.These are :the conversion of aryl halides into nitriles by NaCN'23 and the formation of alkylene carbonates from epoxides and CO '24 catalysed by zerovalent nickel complexes ; acrylic esters and propionaldehyde acetals from acrolein and alcohols in the presence of low-valent Rh Ru and Ir complexes ;125 carbon-carbon bond formation via Rh' complexes;'26 the condensation of aryl halides with olefins catalysed by Pdo;'27*'28 a range of unsymmetrical ketones prepared by the treatment of acid halides with alkyl Rh' c~mplexes;'~~ and the coupling of alkenyl halides in the presence of a Nio complex.'3o T. Nishiguchi K. Tachi and K. Fukuzumi J. Amer. Chem. SOC. 1972,94 8916. l6 U.Klabunde and G. W. Parshall J. Amer. Chem. SOC. 1972,94 9081. I I' M. F. Lappert and P. W. Lednor J.C.S. Chem. Comm. 1973 948. I18 N. G. Hargreaves R. J. Puddephatt L. H. Sutcliffe and P. J. Thompson J.C.S. Chem. Comm. 1973 861. M. P. Brown R. J. Puddephatt and C. E. E. Upton J. Organometallic Chem. 1973 49 C61. IZo A. Tamaki S. A. Magennis and J. K. Kochi J. Amer. Chem. SOC. 1973 95 6487. I2I C. F. Shaw J. W. Lundeen and R. S. Tobias J. Organometallic Chem. 1973 51 365. 122 H. C. Clark and L. E. Manzer Inorg. Chem. 1973 12 362. 123 L. Cassar J. Organometallic Chem. 1973 54 C57. I 24 R. J. De Pasquale J.C.S. Chem. Comm. 1973 157. 12' M. Hidai K. Ishimi J. Iwase E. Tanaka and Y. Uchida Tetrahedron Letters 1973 1189. M. F. Semmelhack and L. Ryono Tetrahedron Letters 1973.2967. ''' M. Julia and M. Duteil Bull. SOC. chim. France 1973 2790. 12' M. Julia M. Duteil C. Grard and E. Kuntz Bull. SOC. chim. France 1973 2791. L. S. Hegedus S. M. Lo and D. E. Bloss J. Amer. Chem. SOC. 1973 95 3040. I3O M. F. Semmelhack P. J. Helquist and J. D. Gorzynski J. Amer. Chem. SOC. 1972 94 9234. 252 J. D. Jones R. Pearce and G. L. P. Randall More examples of internal metallation have appeared. The first examples of internally metallated S-donor ligand complexes have been reported for Fe' and Ru'~~ and in addition the first example involving ortho-B-H bond cleavage.' 33 Crystal structures of internally metallated Ir' complexes have been determined' 34 and whereas arsines will form internally metallated complexes with Pt none was detected with Pd.'35 Previously prepared Pt cluster compounds derived from Pt(PPh,) have been recharacterized as associated Pt" complexes [Pt(PPh2)(C,H4PPh2)I2* 3,0r4 formed through internal meta1lati0n.l~~A new type of internally metallated Mn derivative has been reported.' A new percyanovinyl complex of Pt" is formed by irradiation of the corres- ponding tetracyanoethylene complex.' 38 Other alkenyl transition-metal corn- plexes are produced by electrophilic additions to hexafluorobut-2-yne complexes of Pt Ir and Rh.13' The migration of an alkyl group from a nitrogen atom to a metal ion in a new Rh'-porphyrin complex proceeds concertedly with oxidation to Rh111 140 The cleavage of carbon-carbon bonds with concomitant increase in metal oxidation state by low-valent metal species has been reported.Thus zerovalent Pt and Pd cleave carbonxarbon bonds of ring system^,'^^,'^^ Fe behaves ~irnilarly,'~~ and Pto Ir' and Ru" cleave carbon-carbon bonds in compounds with electron-accepting substituents. 144 Oxidative additions involving the cleavage of other bonds include the nitrogen- chlorine bond of nitrosyl chloride by Mo Wj145or Ni,146 and sulphur-sulphur bond in disulphides by Pt or Pd'47 and the sulphur-hydrogen bond in benzene- thiols by Ir.148 I3l H. Alper and A. S. K. Chan J. Amer. Chem. Soc. 1973,954905. 132 H. Alper and A. S. K. Chan J. Organometallic Chem. 1973 61 C59. 133 E. L. Hoe1 and M. F. Hawthorne J. Amer. Chem. SOC.,1973 95 2712. 13' G. Perego G.Delpiero M. Cesari M. G. Clerici and E. Perrotti J. Organometallic Chem. 1973 54 C5 1. 13' B. L. Shaw and R. E. Stainbank J.C.S. Dalton 1973 2394. IJ6F. Glockling T. McBride and R.J. I. Pollock J.C.S. Chem. Comm. 1973 650. R. J. McKinney B. T. Huie C. B. Knobler and H. D. Kaesz J. Amer. Chem. SOC. 1973 95 633. L38 0.Traverso V. Carassiti M. Graziani and U. Belluco J. Organometallic Chem. 1973 57 c22. 139 R. D. W. Kemmitt B. Y. Kimura and G. W. Littlecott J.C.S. Dalton 1973 636. loo H. Ogoshi T. Omura and 2.Yoshida J. Amer. Chem. Soc. 1973,95 1666. I4l J. A. Evans G. F. Everitt R.D. W. Kemmitt and D. R. Russell J.C.S. Chem. Comm. 1973 158. M. Lenarda R. Ros J. Graziani and U. Belluco J. Organometallic Chem. 1972 46 C29. L43 R. M. Moriarty K.-N.Chen C.-L. Yeh J. L. Flippen and J. Karle J. Amer. Chem. SOC.,1972 94 8944. I. S. Kolomnikov P. Svoboda and M. E. Vol'pin Bull. Acad. Sci. U.S.S.R. 1972 21 2752. M. Deane and F. J. Lalor J. Organometallic Chem. 1973 57 C61. 146 M. Hidai M. Kokura and Y. Uchida Bull. Chem. SOC. Japan 1973 46 686. 147 R. Zanella R. Ros,and M. Graziani Inorg. Chem. 1973 12 2736. 148 J. L. Herde and C. V. Senoff Cunad. J. Chem. 1973,51 1016. Organometallic Compoundsof the Transition Elements 8 Oligomerization and Polymerization Homo-oligomerization.-Further studies of the catalytic cycloaddition of allene with Nio phosphine systems have shown that the selective catalytic reaction path leading to the cyclic trimer (2) tetramer (3) or pentamer (4),is primarily (2) (3) (4) dependent on the nature of the phosphine ligand.'49 The reduction of Ni" phosphine complexes with borohydride or alkoxide produces catalysts for the cyclodimerization of butadiene to either 2-methyl-vinylcyclopentane or n-octatrienes depending upon reduction conditions.' The products from the Rh-catalysed cyclodimerization of butadiene depend on the solvent employed' ' and temperature is important with reduced nickel catalysts.' s2 Modification of a Co"' acetylacetonate-AlEt catalyst with dianil increases the linear dimerization of butadiene from 60 % without modification to >80 %.' s3 Butadiene is oligomerized by (1,5-cod),Ni1s4 and isoprene is dimerized using either Co(acac),-AlEt 'ss or a PdBr,(Ph,PCH,CH,PPh,~sodium phenoxide-phenol system.' s6 A review on the catalysis and mechanism of olefin dimerization by transition- metal complexes has appeared.' s' Both the basicity and bulkiness of the phos- phine favour the formation of 2,3-dimethyl butene rather than hexanes or pentenes from the dimerization of propene by Ni(acac),-Et3A1,C1,-tertiary phosphine catalysts.' '* [(Pr',P),Ni(C,H,),] was isolated from the reaction of ethylene with [(Pr',P),NiHCl] ;further treatment with Lewis acids oligomerizes the co- ordinated ethylene to dimers and trirner~."~ a-Olefins are produced by the oligomerization of ethylene in the presence of Zr complexes' 60,1 and increasingly the acidity of the Phillips catalyst (SO,-149 S.Otsuka K. Tani and T. Yamagata J.C.S. Dalton 1973 2491.150 J. Kiji K. Yamamoto S. Mitani S. Yoshikawa and J. Furukawa Bull. Chem. SOC. Japan 1973,46 1791. 15' P.S. Chekrii M. L. Khidekel I. V. Kalechits 0. N. Eremenko G. I. Karyakina and A. S. Todozhokova Bull. Acad. Sci. U.S.S.R. 1972 21 1521. * F. Furukawa K. Yamamoto S. Mitani and S. Yoshikawa Chem. Letters 1972 121 1. 15' R. Giezynski and S. Pasynkiewicz Przemysl Chem. 1972 51 804. N. Yamazaki and T. Ohta Polymer J. 1973 4 616. I" J. Beger C. Duschek and D. Paul Z. Chem. 1973 13 133. K. Takahashi G. Hata and A. Miyake Bull. Chem. SOC. Japan 1973,46 600. " J. Hetflejs and J. Langova Chem. listy 1973 67 590. 15* Y. Sakakibara T. Tagano M. Sakai and N. Uchino Bull. Inst. Chem. Res. Kyoto Univ. 1972 50 375. N. V. Petrushanskaya A. E. Kurapova and V.Sh. Feldblium Proceedings of the 15th International Conference on Coordination Chemistry Moscow 1973. I6O C. J. Attridge R. Jackson S. J. Maddock and D. T. Thompson J.C.S. Chem. Comm. 1973 132. P. Longi F. Greco and U. Rossi Chimica e Industria 1973 55 252. J. D. Jones R. Pearce and G. L. P. Randall supported chromium oxide) by addition of oxides such as ZnO WO, or MOO produces effective oligomerization catalysts for ethylene.' 62 Diphenylacetylene is catalytically cyclotrimerized to hexaphenylbenzene by (n-C,H,)Rh(CO),.' 63 Evidence for a non-concerted mechanism in cycloadditions involving the stepwise formation of metal-carbon o-bonded intermediates followed by reductive elimination of the hydrocarbon is provided by the isolation of nor- bornadiene-iridium complexes in which two norbornadiene rings form a metallo- cycle by Ir insertion and from which a norbornadiene dimer can be di~p1aced.l~~ Co-o1igornerization.-The substituted olefin 3-methyleneheptane-2,6dionewas obtained by the dimerization of methyl vinyl ketone using various transition- metal triphenylphosphine complexes,' 65 1,4-benzoquinones can be made by the Ni(1,S-cod),-catalysed dimerization of 2,3-disubstituted cyclopropenones,'66 and P-propiolactone is oligomerized by a Cu,O-isocyanide complex.' 67 The pyrrolidone enamine of cyclohexanone reacts with butadiene in the presence of Pd complexes to produce after hydrolysis 2-(2,7-octadienyl)cyclo-hexanone.' 68 The addition of Ph,P to Ni( 1,5-cod) produces a highly selective catalyst for the [2 + 21 cross-addition of norbornadiene and methylenecyclo- propane to (5).'69 The formation of pent-2-ene and 2-methylbut-1-ene from the codimerization of ethylene and propene in the presence of a Ni catalyst is con- sistent with the process of insertion of propene into an ethyl-Ni bond followed by /?-hydrogen elimination.' 70 Certain Rh compounds are effective catalysts for the codimerization of styrene with ethylene propene or butenel'l and the codimerization of a-olefins with 1,3-dienes.l7' The codimerization of butadiene with dicyclopentadiene to form (6) is catakysed by a borohydride-reduced Nil' 16' G. Henrici-Olive and S. Olive Angew. Chem. Internar. Edn. 1973 12 754. 163 S. A. Gardner P. S. Andrews and M. D. Rausch Inorg. Chem.1973 12,2396. 164 A. R. Fraser P. H. Bird S. A. Bezman J. R. Shapley R. White and J. A. Osborn J. Amer. Chem. SOC.,1973 95 597. T. Miyakoshi H. Omiti and S. Saito Nippon Kagaku Kaishi 1973 123. 166 R. Noyori I. Umeda and H. Takaya Chem. Letters 1972 1189. 167 T. Saegusa I. Murase M. Nakai and Y. Ito Bull. Chem. SOC.Japan 1972,45 3604. 16' J. Tsuji Bull. Chem. SOC.Japan 1973 46 1896. 16' R. Noyori T. Ishigami N. Hayashi and H. Takaya J. Amer. Chem. SOC.,1973 95 1674. I'O K. Maruya T. Mizoroki and A. Ozaki Bull. Chem. SOC.Japan 1973,46 993. 17' A. Umezaki Y. Fujiwara K. Sawara and S. Teranishi Bull. Chem. SOC.Japan 1973 46 2230. A. C. L. Su and J. W. Collette J. Organometallic Chem. 1972 46 369. 255 Organometallic Compounds of the Transition Elements phosphine complex,' and alternating co-oligomers are produced by the action of VO(acac),-Et,Al-Et,AlCl on an isoprene-propene mixture.'74 Oligomerization with Addition.-Nickel catalyses the oligomerization of buta-diene to alkoxy-octadienes in the presence of alcohols'75 and to phenoxy- octadienes in the presence of and the reaction of allene with amines or active methylene compounds to give compounds of the type (7).177 Pd compounds catalyse the selective reaction of acetic acid with butadiene to give acetoxy~ctadienes'~ * and the hydrodimerization of butadiene to octa-1,7- diene.I7 Polymerization Reactions Catalysed by Non-Ziegler Systems.-Tris-n-allyl-chromium supported on silica-alumina will copolymerize isoprene-butadiene mixtures,"' Ni Zr Cr Mo and Co allyls polymerize 2-alkylb~ta-l,3-dienes,'~~ n-allylic Ni complexes stereospecifically polymerize 2,3-dimethylbutadiene and cyclohexa- 1,3-diene and copolymerize butadiene with other dienes.' 82 The relative reactivities of a series of dienes and butadiene-styrene copolymerizations using various catalysts based on transition-metal allylic compounds have been 173 S.Yoshikawa S.Nishimura J. Kiji and J. Furukawa Tetrahedron Letters 1973,3071. 174 J. Furukawa S. Tsuruki and J. Kiji J. Polymer Sci. Part A-1 Polymer Chem. 1973 11 1819. 175 J. Beger C. Duschek and H. Fullbier 2. Chem. 1973 13 59. 176 F. J. Weigert and W. C. Drinkard J. Org. Chem. 1973 38 335. 177 R. Baker and A. H. Cook J.C.S. Chem. Comm. 1973,472. D. Rose and H.Lepper J. Organometallic Chem. 1973 49 473. P. Roffia G. Gregorio F. Conti G. F. Pregaglia and R. Ugo J. Organometallic Chem. 1973 55 405. Ieo V. L. Shmonina N. N. Stefanovskaya E. I. Tinyakova and B. A. Dolgoplosk Proc. Acad. Sci. (U.S.S.R.),1973 209 227. Is' V. A. Vasiliev N. A. Kalinicheva V. A. Kormer M. I. Lobach and V. I. Klepikova J. Polymer Sci. Part A-I Polymer Chem. 1973 11 2489. "* B. A. Dolgoplosk S.I. Beilin Yu. V. Korshak; G. M. Chernenko L. M. Vardanyan and M. P. Teterina European Polymer J. 1973 9 895. 256 J. D. Jones R. Pearce and G. L. P.Randall studied.lS3 The reaction products from Zr tetra-ally1 and TiC14 will initiate the cationic polymerization of isoprene. Transition-metal complexes are proving particularly useful for the polymeriza- tion and copolymerization of polar monomers; thus Rh' complexes in the presence of organic halides effect the free-radical polymerization of methyl methacrylate (MMA),'85 iron complexes will initiate the polymerization of styrene (ST) acrylonitrile (AN) methacrylonitrile (MAN) and MMA,ls6 and it has been demonstrated using deuteriated MMA that opening of the double bond occurs in the polymerization catalysed by diethylbis(bipyridy1)- iron.' 87 Cobalt hydrido and methyl complexes will initiate the polymerization of AN MAN and MMA'88 and the reactivity of polar monomers to polymeriza- tion effected by Co carbonyl complexes has been re~0rted.l~~ Tetrabenzyl Zr polymerizes ST by a co-ordinated anionic mechanism.' 90 Carbonyl complexes of Mn and Re are active photoinitiators of the free-radical polymerization of tetrafluoroethylene ;in addition these carbonyls in the presence of low concen-trations of tetrafluoroethylene will photoinitiate polymerization of ST.MMA and AN.'91 The free-radical polymerization of AN and MMA is also initiated by a-amino-acid ester Cu" systems.' 92 Poly(Schiff bases) are produced by the nickel-catalysed polymerization of isocyanides.' 93 9 Insertion Reactions The complex [PtH(C2H4)(PEt,),]BPh4 an intermediate in the insertion of ethylene into Pt-hydride bonds has been isolated'94 and other insertions into metal-hydride bonds have been reported. The insertion of functionally substi- tuted allylic compounds into cationic Pt" hydrides involves an initial migration of the double bond,lg5 the ortho-olefinic moiety of a chelating phosphine ligand will insert into Pt-H bonds,'96 and olefins and acetylenes insert into Ir"' hydride~.'~' The insertion of substituted acetylenes into R-methyl bonds B.A. Dolgoplosk S. I. Beilin Yu. V. Korshak K. L. Makovetsky and E. I. Tinyakova J. Polymer Sci. Part A-1 Polymer Chem. 1973 11 2569 V. A. Kormer V. A. Vasiliev N. A. Kalinicheva and 0.I. Belgordskaya J. Polymer Sci. Part A-1 Polymer Chem. 1973 11 2557. N. Kameda and N. Itagaki Bull. Chem. SOC. Japan 1973,46 2597. Y. Kubo A. Yamamoto and S. Ikeda J. Organometallic Chem. 1972 46 C50. T. Yamamoto A. Yamamoto and S. Ikeda J. Polymer Sci. Part B Polymer Letters 1972 10 835. "' Y. Kubo A. Yamamoto and S. Ikeda J.Organometallic Chem. 1973 59 353 lS9 G. Palyi F. Baumgartner and I. Czajlik J. Organometallic Chem. 1973 49 C85. I9O D. G. H. Ballard J. V. Dawkins J. M. Key and P. W. van Lienden Makromol. Chem. 1973 165 173. l9I C. H. Bamford and S. U. Mullik Polymer 1973 14 38. 192 K. Azuma Y. Inaki and K. Takemoto Makromol. Chem. 1973 166 189. '93 R.J. M. Nolte R. W. Stephany and W. Drenth Rec. Trav. chim. 1973 92 83. '94 A. J. Deeming B. F. G. Johnson and J. Lewis J.C.S. Dalton 1973 1848. '95 H. C. Clark and H. Kurosawa Inorg. Chem. 1973 12 357. '96 P. R. Brookes J. Organometallic Chem. 1973 47 179. 197 H. C. Clark and R. K. Mittal Canad. J. Chem. 1973 51 151 1. Organometallic Compounds of the Transition Elements 257 proceeds by a free-radical mechanism,' 98 insertion of 1,2-dienes1 99 and strained olefins2" into Pd-ally1 bonds proceeds viao-ally1 intermediates and interestingly the insertion of isoprene into n-crotyl-Ni bonds differs from that of n-allylic palladium in that the n-crotyl group bonds to the methylene carbon of the diolefin.20' The insertion of isocyanide into the Pt-alkyl or -aryl bonds of dialkyl or diary1 Pt phosphine complexes202 is dependent upon the nature of the phosphine and the isocyanide and is not so general as those into monoalkyl complexes.203 The crystal structure of a typical isocyanide insertion product has been deter- mined.204 Insertion of SO into Fe- Mo- Mn- and Re-alkyl bonds to form sulphur- bonded sulphinates involves the initial formation of oxygen-bonded inter- mediate~,~~~,~~~ and studies indicate that SO insertion into an Fexarbon bond occurs with retention of configuration at Fe.,07 Insertion of SO into Ptxarbon bonds is faster than that of carbon monoxide.208 New metal-acyl complexes of Ni209 by CO insertion into a Ni-methyl bond and of Cr,," by treatment of phosphines with h5-C5H5Cr(CO),Me have been prepared.The decarbonylation of (h5-C H 3-1-Me-3-Ph)Fe(CO) (PPh,) (COMe) is highly stereospecific.2 '' Other insertions of small molecules into metalkdement bonds include chloro- sulphonylisocyanate into Fexarbon, ' CO into Cu-methyl,2' aldehydes into Co-and Ni-ally1,2'4 0 into Coxarbon of alkyl cobaloxime~,~'~,~~~ carbon dioxide2l7 and carbon disulphide218 into Ru-hydride the =C(CF,) group 19' T.G. Appleton M. H. Chisholm and H. C. Clark J. Amer. Chem. Soc. 1973 94 8912. IQ9 R. P. Hughes and J. Powell J. Organometallic Chem. 1973 60 409. 2oo R. P. Hughes and J. Powell J. Organometallic Chem. 1973 60 387. 201 V. A. Vasl'ev V. I. Klepikova G. P. Kondratenkov V. A. Kormer and M. I. Lobach Proc. Acad. Sci. U.S.S.R. 1973 206 719. 202 P. M. Treichel and K. P. Wagner J. Organometallic Chem. 1973 61 415. '03 P. M. Treichel K. P.Wagner and R. W. Hess Inorg. Chem. 1973 12 1471. 204 K. P. Wagner P. M. Treichel and J. C. Calabresse J. Organometallic Chem. 1973 56 C33. 'OS S. E. Jacobson P. Reich-Rohrwig and A. Wojcicki Inorg. Chem. 1973 12 717. 206 S. E. Jacobson and A. Wojcicki J. Amer. Chem. Soc. 1973 95 6962. 207 T. C. Flood and D.L. Miles J. Amer. Chem. Soc. 1973 95 6460. *08 F. Faraone L. Silvestro S. Sergi and R. Pietropaolo J. Organometallic Chem. 1972 46 379. 209 H.-F. Klein Angew. Chem. Internat. Edn. 1973 12 402. 210 K. W. Barnett D. L. Beach and T. G. Pollman Inorg. Nuclear Chem. Letters 1973 9 131. 211 T. G. Attig P. Reich-Rohrwig and A. Wojcicki J. Organometallic Chem. 1973 51 c21. 'I2 Y. Yamamoto and A. Wojcicki Inorg. Chem. 1973 12 1779. 213 A. Miyashita and A. Yamamoto J. Organometallic Chem. 1973 49 C57. 214 G. Agnes G. P. Chiusoli and A. Marraccini J. Organometallic Chem. 1973 49 239. 21s F. R. Jensen and R. C. Kiskis J. Organometallic Chem. 1973 49 C46. C. Giannotti and B. Septe J. Organometallic Chem. 1973 52 C36. 217 S. Komiya and A. Yamamoto J.Organometallic Chem. 1972 46,C58. 2'a R. 0. Harris N. K. Hota L. Sadavoy and J. M. C. Yuen J. Organometallic Chem. 1973 54 259. 258 J. D. Jones R. Pearce and G. L. P. Randall into Pt- and Pd*hl~rine,~ l9 keto- and vinyl-carbenes into Pd-chlorine.220 and nitric oxide into C-lefin bonds.221 The expansion of a four-membered ring bound to Fe by insertion of a -CF group into a carbon4arbon bond has been reported222 and a series of five- membered-ring-metal complexes have been prepared by the insertion of various organofluoro-compounds into three-membered-ring Pt and Ni c~mplexes.~~~,~~~ One of these organofluoro-compounds (CF,),CO also inserts into carbon- hydrogen bonds of organic moieties bonded to Fe Rh,225 and Ru.226 The insertion of an ethylacetatocarbene species into the 0-H bond of alcohols is catalysed by homogeneous Rh 10 Asymmetric Induction and Stereospecific Syntheses Transition-metal catalysts are increasingly being employed for the preparation of specific stereoisomeric compounds.Further work has appeared on the asym- metric reduction of ketones to alcohols catalysed by a chiral phosphine-rhodium complex,228 and the crystal structure of a Co complex used in the asymmetric hydrogenation of various unsaturated has been determined.230 The modification of catalyst surface enhances the activity for asymmetric hydro- genation reactions. Treatment with either L-glutamic or D-tartaric acid protects the surface of Raney Ni from corrosion. Whereas the protective effects are greater with the amino-acid the activity for the hydrogenation of acetylacetone is higher for the hydroxy-acid ;231 in addition the activity for a hydroxydicarbo- xylic acid modified catalyst in the hydrogenation of methylacetoacetonate is maximized at pH 5-8.232 D-tartaric acid m0dified.R~ catalysts have been used for the hydrogenation of the carbonyl group in acetoacetic ester,z33 and boro- hydride-reduced Ni modified with ethylenediamine greatly increases the cis-trans ratio in the stereospecific hydrogenation of alkynes to alkene~.~~~ The first 219 J.Clemens M. Green and F. G. A. Stone J.C.S. Dalton 1973 1620. 220 N. Yoshimura S.-I. Murahashi and J. Moritani J. Organometaffic Chem. 1973 52 C58. 221 H. Brunner and S. Loskot J. Organometaffic Chem.1973 61 401. 222 A. Bond M. Green and S. H. Taylor J.C.S. Chem. Comm. 1973 112. 223 J. Browning H. D. Empsall M. Green and F. G. A. Stone J.C.S. Dalton 1973 381. 224 P. K. Maples M. Green and F. G. A. Stone J.C.S. Dalton 1973 388. zzs M. Green and B. Lewis J.C.S. Chem. Comm. 1973 114. 226 T. Blackmore M. I. Bruce F. G. A. Stone R. E. Davis and N. V. Raghavan J. Organo- metallic Chem. 1973 49 C35. 227 R. Paulissen H. Reimlinger E. Hayez A. J. Hubert and Ph. Teyssie Tetrahedron Letters 1973 2233. 22a M. Tanaka Y. Watanabe T. Mitsudo H. Iwane and Y. Takegami Chem. Letters 1973 239. 229 S. Takeuchi Y. Ohgo and J. Yoshimura Chem. Letters 1973 265. 230 Y. Ohashi Y. Sasada Y. Tashiro Y. Ohgo S. Takeuchi and J. Yoshimura Buff. Chem. SOC. Japan 1973,46 2589.23' T. Tanabe Bull. Chem. SOC.Japan 1973 46 1482. 232 T. Tanabe K. Okuda and Y. Izumi Bull. Chem. SOC. Japan 1973,46 514. 233 E. I. Klabunovskii N. P. Sokolova A. A. Vedenyapin Yu. M. Talanov N. D. Zubareva V. P. Polyakova and N. V. Gorina Bull. Acad. Sci. U.S.S.R.,1972 21 2306. 234 C. A. Brown and V. K. Ahuja J.C.S. Chem. Comm. 1973 553. Organometallic Compounds of the Transition Elements 259 report of a Ni-catalysed selective reduction of exocyclic methylene groups important synthetically and industrially has a~peared.~ Asymmetric hydrosilylation reactions are proving useful for the preparation of specific organic products. Chiral Rh complexes catalyse the asymmetric hydrosilylation of ketones ;236.23 optically active carbinols are produced by the Pt"-catalysed addition of a silane to ketones :238 whereas an insoluble chiral polymer-supported Rh complex related to soluble Rh'diop has a low efficiency for asymmetric hydrogenation both the insoluble and soluble catalysts are very efficient for the asymmetric silylation of ketones.239 Rhl-diop is also used in the preparation of asymmetric amine~,~~' and the asymmetric hydroformylation of aliphatic olefinsZ4l and styrene.242 The asymmetric hydrocarboxylation of olefins can be achieved using chiral Pd complexes.243 The first catalytic asymmetric synthesis in which a chiral centre results from carbon-carbon bond formation has been reported for the Ni-catalysed co- dimerization of cyclo-octa- 1,3-diene and ethylene ;244 butadiene is dimerized stereospecifically with a Zr complex245 and whereas the polymerization of butadiene with a Ni complex gives mainly the cis-1,4 an ally1 Cr catalyst gives predominantly trans-l,4-~tructures.~~~ Certain cross-coupling reactions proceed stereospecifically ;Grignard reagents react with monohalogeno-olefins in the presence of Ni248 and the addition of alkyl halides to vinyl-Rh' complexes is followed by a reductive elimination yielding trisubstituted 01efins.~~' The first report of a high stereo- and regio-selective Vor Mo catalysed epoxida- tion in a complex molecule synthesis provides a remarkable demonstration of the use of a transition-metal catalyst to give products not obtainable with any other reagent .250 235 J.H. P. Tyman and S. W.Wilkins Tetrahedron Letters 1973 1773. 236 I. Ojima T. Kogure and Y. Nagai Chem. Letters 1973 541. 237 K. Yamamoto T. Hayashi and M. Kumada J. Organometallic Chem. 1973 54 c45. 238 K. Yamamoto T. Hayashi and M. Kumada J. Organometallic Chem. 1972 46 C65. 239 W. Dumont J.-C. Poulin T.-P. Dang and H. B. Kagan J. Amer. Chem. Soc. 1973 95 8295. 240 N. Langlois T.-P. Dang and H. B. Kagan Tetrahedron Letters 1973 4865. 24' G. Consiglio C. Betteghi C. Salomon and P. Pino Angew. Chem. Internat. Edn. 1973 12 669. 242 C. Salomon G. Consiglio C. Botteghi and P. Pino Chimia (Switz.) 1973 27 215. 243 C. Botteghi G. Consiglio and P. Pino Chimia (Switz.) 1973 27 477. B. Bogdanovic B. Henc B. Meister H. Pauling and G. Wilke Angew. Chem. Internat. Edn. 1972 11 1023.245 H.-J. Kablitz and G. Wilke J. Organometallic Ckm. 1973 51 241. 246 I. Ya. Ostrovskaya and K. L. Makovetskii Proc. Acad. Sci. (U.S.S.R.),1973,208 110. 247 V. L. Shmonina. N. N. Stefanovskaya E. I. Tinyakova. and B. A. Dolgoplosk, Vysokomol. Soedineniya (A) 1973 15 647 (Chem. Abs. 1973 79 53 851r). 24a K. Tomao M. Zembayashi Y. Kiso and M. Kumada J. Organometallic Chem. 1973 55 C9 1. 249 J. Schwartz D. W. Hart and J. L. Holden J. Amer. Chem. SOC. 1972 94 9269. 250 K. B. Sharpless and R. C. Michaelson J. Amer. Chem. SOC. 1973 95 6136. 260 J. D. Jones R. Pearce and G. L. P.Randall 11 Isomerization Carbon-Carbon Double-bond 1somerizations.-The majority of papers in this area have no immediate application to synthetic organic chemistry ; however they do extend the scope of these isomerization~.~~'-~~* Mechanistic information on these reactions has been extended by isotope studies of homogeneous iso- meri~ations~~~ and also by the determination of the relative stabilities ofpalladium pentene complexes.260 Of particular interest is the isomerization of cis,rrans-cyclodeca- 1,6-diene to cis,tmns-and cis,cis-cyclodeca- 1,5-diene which is cata- lysed by RuCl,,xH,O in this conversion cannot be carried out thermally.The catalytic isomerization of allyl to propenyl ethers has been used as a step in a new method of protecting a hydroxy-group.262 The hydroxy-function to be protected is converted into an allyl ether which can only be cleaved by very strong acid or base or by SeO oxidation.When the hydroxy-group is to be regenerated the allyl ether is catalytically isomerized to a propenyl ether which can be cleaved under dilute acid conditions (pH2). In the procedure described above R hCl(PPh,) was used as the isomerization catalyst ; however Pd(PhCN),Cl also catalyses the reaction.263 The isomerizations of ligands which remain co-ordinated to a metal are of interest in so far as they can indicate how related catalytic transformations occur. Amongst these are the conversion of the n-ally1 in x-allylirondicarbonyl iodide into a a-propenyl ligand under the influence of the co-ordination of a trispyrazolyl- borate ligand,264 the rearrangement of a a-but-3-enyl group co-ordinated to nickel to a C4 allyl by heat or irradiation,265 and the conversion ofa 1,l-dimethyl- n-ally1 ligand on Co or Rh into a 1,2-dimethyl-n-ally1.266 Isomerization of Carbon Skeletons.-There has been a large amount of informa-tion concerning the extension of these reactions and the mechanistic route by which they proceed.The reactions are divided into three types. '" B. Corain and G. Puosi J. Catalysis 1973 30 403. ' J. E. Lyons J. Catalysis 1973 28 500. 2s3 B. R. James L. D. Markham B. C. Hui and G. L. Rempel J.C.S. Dalton 1973 2247. 254 C. Eaborn N. Farrell and A. Pidcock J.C.S. Chem. Comm. 1973 766. 255 W. Strohmeier J. Organometallic Chem. 1973 60,C60. W. Strohmeier R. Fleischmann and W. Rehder-Stirnweiss J. Organometallic Chem. 1973 47 C37. 257 Y. M. Zhorov G. V. Demidovich and G. M. Panchenkov Kinetika i Kataliz 1973 14 809.258 B. Corain and G. Puosi J. Catalysis 1973 30 403. '" B. I. Cruikshank and N. R. Davies Austral. J. Chem. 1973 26 1935. 260 G. F. Pregaglia F. Conti B. Minasso and R. Ugo J. Organometallic Chem. 1973,47 165. 26' D. L. Schmitt and H. B. Jonassen J. Organometallic Chem. 1973,49,469. 262 E. J. Corey and J. W. Suggs J. Org. Chem. 1973,38 3224. 263 P. Goldborn and F. Scheinmann J.C.S. Perkin I 1973 2870. 264 R. B. King and A. Bond J. Organometallic Chem. 1973 46 C53. 265 J. M. Brown and K. Mertis J.C.S. Perkin II 1973 1993. 266 M. A. Cairns J. F. Nixon and B. Wilkins J.C.S. Chem. Comm. 1973 86. Organometallic Compoundsof the Transition Elements 26 1 lsomerizations which Generate Additional Carbon Rings.The influence of transition-metal co-ordination on the equilibrium between cyclo-octa- 1,3,5- triene and bicyclo[4,2,0]octa-2,4-diene has been demonstrated by co-ordination to Fe(CO) .267 The co-ordinated polyene favours the monocyclic isomer as compared with the unco-ordinated which prefers the bicyclic structure. In the field of catalytic synthesis bicyclo[3,3,0]oct-2-ene has been made from 1,5-cod using Ni 2-ethylhexanoate and C2H,AIC12 as catalyst.268 Isomerizations which Reduce the Number of Carbon Rings. The ring-opening reactions of bicyclobutanes have received a great deal of attention. N~yori~~' has rationalized the catalytic transformations which occur with a variety of metals on the basis of the relative electrophilic or nucleophilic nature of the carbene intermediates.A labile carbene intermediate generated in the Rh- catalysed isomerization of 1-methylbicyclo[ l,l,O]butane has been trapped by reaction with methyl acrylate :270 Me3 + CH,=L-CH,CH-Rh + CH,-4C0,Me A marked substituent effect has been noted in the product distribution obtained in the silver-ion-catalysed isomerizations of tricycloheptanes which may be related to carbene intermediate^.^" The understanding of the mechanism of iron-carbonyl-catalysed isomerizations of cyclopropanes has been improved by the isolation of some trimethylenemethane-Fe(CO) complexes from one of these reaction^.^^^.^^^ Among extensions of these isomerizations are the conversion of quadri-cyclene derivatives into norbornadienes by univalent Ag274 and Rh275 and the unusual cleavage of cyclohexadiene by Ru,(CO), to give a linear p-ally1 co- ordinated to a Ru carbonyl Isomerizations Maintaining the Same Number of Carbon Rings.Mechanistic information on the bond reorganization of homocubanes by homogeneous 267 M. Brookhart N. M. Lippman and E. J. Reardon J. Organometallic Chem. 1973 54 247. 26a N. A. Maly H. Menapace and M. F. Farona J. Catalysis 1973,29 182. 269 R. Noyori Tetrahedron Letters 1973 1691. 'lo P. G. Gassman and R. R. Reitz J. Organometallic Chem. 1973 52 C51. 27' G. Zon and L. A. Paquette J. Amer. Chem. SOC. 1973,95 4456. 272 W. E. Billups L. P. Lin and B. A. Baker J. Organometallic Chem. 1973 61 C55. 273 I. S. Koull J. Organometallic Chem. 1973 57 363. 274 G. F. Koser P.R. Pappas and S.-M. Yu Tetrahedron Letters 1973,4943. 275 M. Hogeveen and B. J. Nusse Tetrahedron Letters 1973 3667. 276 T. H. Whitesides and R. A. Budnik J.C.S. Chem. Comm. 1973 87. J. D. Jones R. Pearce and G. L.P. Randall silver salts suggests that reversible Ag-C bond formation occurs and that there is little evidence for carbonium ion intermediate^.^^' A deuteriation study of the stereospecific addition of acetic acid to norborna- diene catalysed by Pt complexes indicates that a bond reorganization has oc- c~rred.~~~ A ring-expansion reaction has been described when 1.2-divinyl-cyclobutane co-ordinates to Pd to give a 1,5-cod complex.279 12 Carbonylation Reactions Used in Organic Synthesis There have been a large number of reports of transition-metal-catalysed carbonyl-ations this year.The use of complexes of metals other than Co and Rh is in- creasing although no significant improvements have been noted. Reviews on olefin hydroformylation280 and CO insertion into transition-metalkarbon bonds28 have been published. High-pressure i.r. spectroscopy has been a useful technique for determining the species present under hydroformylation conditions. Iridium carbonyl phosphine catalysts have been shown to break down to monomeric carbonyl hydrides from Ir clusters under reaction conditions.282 It has also been demon- strated that cyclohexenyl hydroperoxide activates the (PPh,),Rh(CO)Cl hydro- formylation catalyst by promoting the formation of cis-(PPh,)Rh(CO),Cl which is a very active catalytic species.283 The use of the tetracarbonylferrate anion in organic syntheses involving carbonylation has been extended and closely related anions have also been used for similar reactions.The general intermediate (CO),FeCOR made by the reaction of an alkyl bromide or tosylate followed by treatment with CO may be converted into a variety of carboxylic acid derivatives (Scheme 1). These (CO),FeCOR' R'C02H 1 R'CO~R~ R 'C02NRZR Scheme 1 reactions give isolated yields of 80%.284The reaction conditions do not affect either ester or ketone functions as demonstrated by the transformation shown in 2" L. A. Paquette and J. S. Ward Tetrahedron Letters 1973 4909. 278 E. F. Magoon and L. H. Slaugh J. Organometallir Chem. 1973,55,409. 279 P.Heimback and M. Molin J. Organometallic Chem. 1973 49 483. J. Falbe Propylene and its industrial Derivatives 1973 333. 281 A. Wojcicki Adv. Organometallic Chem. 1973 11 88. 282 A. J. Drakesmith and R. Whyman J.C.S. Dalton 1973 362. 283 H. B. Tinker and D. E. Morris J. Organometallic Chem. 1973 52 C55. 284 J. P. Collman. S. R. Winter and R. G. Komoto J. Amer. Chem. SOC. 1973 95 249. 263 Organometallic Compounds of the Transition Elements Scheme 2. The tetracarbonylferrate reagent may be used to make hemifluorinated ketones containing nitrile or chloro functions285 and also in the preparation of cyclic ketones from ethylenic bromides and allenic bromides.286 The related 0 0 II 0-c/\1 Scheme 2 anion CpFe(CO),-may be used in a similar manner but a cupric salt is required as an oxidizing agent in the carbonylation and metal removal step.287 Nickel tetracarbonyl has been used as a catalyst in the synthesis of l-alkyl-2-phenylindolin-3-ones from phenyl iodide and N-benzylidene-alkylamines :288 0 PhI + PhCH=NMe -+ (PhCONMeCHPh) The same carbonyl is used to carbonylate aryl halides in aprotic solvents with base and one atmosphere of C0.289 Olefins and saturated hydrocarbons may be converted into tertiary carboxylic acids under one atmosphere of CO at ambient temperature by a cuprous salt in concentrated sulphuric acid.290*291 The cation Cu(CO) + is suggested as the catalyst in these reactions.The rhodium catalyst (PPh,),RuCl has been used to decarbonylate an aldehyde selectively in the presence of an ester292 and silver perchlorate has also been used as a decarbonylation catalyst for strained-ring ketones.293 13 Addition and Substitution Reactions at Co-ordinated Ligands This subject has been the topic of a large number of publications recently and has been divided into two sections.lH5 J. P. Collman and N. W. Hoffman J. Amer. Chem. SOC.,1973,95 2689. J. Y. Merour J. L. Roustan C. Charrier J. Collin and J. Benaim J. Organomerallic Chem. 1973,51 C24. K. M. Nicholas and M. Rosenblum J. Amer. Chem. Soc. 1973,95 4449. 2H8 M. Ryang Y. Toyoda S. Murai N. Sonoda and S. Tsutsumi J. Org. Chem. 1973 38 62. 289 L. Cassar and M. Foa J. Org. Chem. 1973 51 381. ‘90 Y. Souma H. Sano and J. Iyoda J. Org. Chem. 1973 2016. 291 Y.Souma and H. Sano J. Org. Chem. 1973 3633. 292 B. M. Trost and M. Preckel J. Amer. Chem. SOC..1973 95 7862. 293 H. Ona M. Sakai M. Suda and S. Masamune J.C.S. Chem. Comm. 1973,45. J. D. Jones R. Pearce and G. L. P. Randall The Understanding aod Discovery of New Reactions of Functional Groups Pro-moted by Co-ordination to a Transition Metal.-The modification of the reactivity of co-ordinated nitriles and isocyanides has received much attention. An in- vestigation of the addition of hydrazine to the ligands in (RNC),PtZ+ has shown that the products (8) consist of two isocyanide residues linked by an N-N Nucleophiles such as thiols alcohols and amines produce co-ordinated carbenes by attack at isocyanide arbo on.^^^-^^' It has been proposed that the catalytic homogeneous hydration of nitriles proceeds by a related attack of hydroxide at the carbon of a co-ordinated nitrile followed by proton transfer and hydrolysis.298 The activation of olefins and dienes towards nucleophilic attack is an interesting result of co-ordination to transition metals.The Pt-olefin system has been investigated by n.m.r.,299 and it has been found that olefins co-ordinated to Fe" react with enolate anions to give the corresponding iron alk~1.~'' Reversible nucleophilic addition to butadiene which is co-ordinated to Mo has been demon- strated in the complex (9).301 Q Nucleophilic addition of PPh to cyclohexadienyl- and cycloheptadienyl- Fe(CO) complexes gives phosphonium derivatives and pyridine adds in a similar way.3o2 In the related open-chain pentadienyl complexes the product of reaction with nucleophiles either addition or H+ removal is dictated by the substituents on the pentadienyl chain.303 Electrophilic addition of C2(CN) 294 W.M. Butler J. H. Enemark J. Parks and A. L. Balch Inorg. Chem. 1973 12 451. 295 W. M. Butler and J. H. Enemark Inorg. Chem. 1973 12,540. 296 B. Crociani T. Boschi G. G. Troilo and U. Croatto Inorg. Chim. Acta 1972 6 655. 297 J. Chatt R. L. Richards and G. M. D. Royston Inorg. Chim. Acta 1972 6 669. 298 M. A. Bennett and T. Yoshida J. Amer. Chem. Soc. 1973,95 3030. 299 D. Hollings M. Green and D. V.Claridge J. Organometallic Chem. 1973 54 399. 300 A. Rosan M. Rosenblum and J. Tancrede J. Amer. Chem. SOC. 1973 95 3062. 301 M.L. H. Green L. C. Mitchard and W. E. Silverthorn J.C.S. Dalton 1973 1952. 302 J. Evans D. V. Howe B. F. G. Johnson and J. Lewis J. Organometallic Chem. 1973 61 C48. '03 P. McArdle and M. Sherlock J. Organometallic Chem. 1973 52 C29. Organometallic Compounds of the Transition Elements to (cycloheptatriene)Fe(CO) gives an exo-l,3-addition and it has been shown that in (ditropyl jFe(CO) the unco-ordinated cycloheptatriene ring is the first to react with C,(CN),.305 The Synthetic Use of Transition-metal-promoted Additions and Substitutions.-There have been several very interesting reports covered by this heading. The synthesis of Vitamin K has been carried out by the use of a n-allyl-Ni derivative.,06 In this reaction the bromine of an aryl halide is replaced by a substituted ally1 group in high yield.The addition of an amine to a n-allyl-Ni complex produced by a Ni-H addition to butadiene is suggested as the important step in the synthesis of butenylamine from butadiene and amine in 60% yield.," Iron tricarbonyl complexes have found use in the preparation of cyclopentanones from 1,l'-dibromoketones and 01efins.~'~ The oxyallyl ligand is suggested as the intermediate to which olefin adds. Terpene complexes of Fe(CO) may be isomerized and have addition reactions carried out on them which do not occur in the unco-ordinated materials. These properties have been used in some terpene transformation^.^^^ Birch and his co-workers have studied the removal of Fe(CO), which is an essential step in any synthesis involving an Fe(CO) Besides the efficient removal of the Fe(CO) group under mild conditions a chemical transformation of the ligand can be achieved by careful choice of reagents (Scheme 3).CH,COMe A FeCI inw/ethanolic lpb(o\ d3 c=o I c=o Scheme 3 304 M. Green S. Heathcock and D. C. Wood J.C.S. Dalton 1973 1564. 305 P. McArdle J.C.S. Chem. Comm. 1973 482. 306 K. Sato S. Inoue and K. Saito J.C.S. Perkin I 1973 2289. 307 J. Kiji K. Yamamoto E. Sasakowa and J. Furukawa J.C.S. Chem. Comm. 1973 770. 308 R. Noyori. K. Yokoyama and Y. Hayakawa. J. Amer. Chem. SOC.,1973,95 2722. 309 D. V. Banthorpe H. Fitton and J. Lewis J.C.S. Perkin I 1973 2051. 3 10 A. J. Birch K. B. Chamberlain M. A. Haas and D. J. Thompson J.C.S.Perkin I 1973. 1882. 266 J. D. Jones R. Pearce andG. L. P.Randaii The Pd-catalysed addition of secondary amines to both carbon-carbon double bonds and carbon-nitrogen double bonds has been used to prepare pyrimidenes in 75 % yield from secondary amines and a,~-diamines.~ 14 Heterogeneous Catalysts Derived from Known Homogeneous Systems The modification of homogeneous catalysts to operate in a heterogeneous mode has the attraction of possibly being able to combine the most attractive features of each system. The adaptation of homogeneous hydroformylation catalysts to heterogeneous systems by supporting on a polymer backbone has been discussed in a review of hydrof~rmylation.~' The preparation of polymer-attached hydrogenation catalysts as a means of making them heterogeneous has received some attention.The hydrogenation catalyst (PPh,),RhCl has been made heterogeneous by replacing a PPh by a cross-linked phosphinated poly~tyrene.~ The catalytic activity is reduced by a factor of 16 but the catalyst is readily removed from the reaction medium by simple filtration. It shows selectivity for small substrates and may be used as a suspension in a polar solvent to hydrogenate selectively non-polar olefins in the presence of polar ones. Platinum and palladium hydrogenation catalysts have been made heterogeneous in a similar way. ' Polymer-supported palladium catalysts have also been used in the following reaction :315 / Me,SiOH + -+ Me,SiO The polymerization catalyst PhNi(bipy)Cl has been supported by replacing the monomeric phenyl group by that of polystyrene derived from 4-chloro- p~lystyrene.~'~ The polymerization activity is very poor but with added EtAlCl as an activator ethylene and propylene may be dimerized.15 Metathesis of Olefins and Acetylenes The majority of publications on this subject involve the use of WCl ,EtAlCl as an olefin metathesis catalyst ;however there have been some useful developments with applications. The alternative co-catalyst LiAlH has been used with WC1 to convert hept-3-ene into oct-4-ene and hex-3-ene. l7 The attraction of this co-catalyst is its stability towards oxygen. It has been found that the extent to which alkylation of aromatic solvent occurs using WCl ,EtAICI catalysts is very dependent on the ratio of olefin to Polybutadiene has been ' N.Yoshimura I. Moritani T. Shimamura and S.-I. Murahashi J. Amer. Chem. SOC. 1973 95 3038. 'I2 P. W. H. L. Tjan Chem. Weekblad 1973 69 K11. 313 R. H. Grubbs L. C. Kroll and E. M. Sweet J. Macromof. Sci. Chem. 1973 7 1047. 3'4 H. Bruner and J. C. Bailar Inorg. Chem. 1973 12 1465. 'I5 M. Capka P. Svoboda and J. Hetflejs Cofl.Czech. Chem. Comm. 1973 38 1242. '' S. Ikeda and T. Harimoto J. Organometaffic Chem. 1973 60 C67. 3'7 S. A. Math and P. G. Sammes J.C.S. Chem. Comm. 1973 174. 318 L. Hocks. A. J. Hubert and P. Teyssie Tetrahedron Letters 1973 2719. OrganometallicCompoundsof the TransitionElements 267 used as a substrate for metathesis with oct-4-ene319 and d0dec-6-ene.~~' The same polymer has been disproportionated using both WCl ,EtAIC12 and (C4H,),Mo,EtA1C12 catalysts to give lower molecular weight polymer together with cyclo-octadiene and cycl~dodecatriene.~~' The structure determination of a complex obtained from the reaction of a cyclic diyne with Fe,(CO), indicates that the ligand is a product of the meta- thesis of the di~ne.~~~ 319 K.Hummel and W. Ast Die Makro. Chem. 1973 166 39. 320 K. Hummel D. Wewerka F. Lorber and G. Zeplichal Die Makro. Chem. 1973 166 45. 321 E. N. Kropacheva D. E. Sterenzat Y. A. Patrushin and B. A. Dolgoplosk Proc. Acad. Sci. (U.S.S.R.),1973 206 776. 322 H. B. Chin and R. Bau J. Amer. Chem. SOC. 1973 95 5068.

 



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