摘要:

AbstractThe thermolysis of [CpFe(CO)2]2(1) and P4or As4affords the iron clusters [Cp4Fe4(E2)2], E = As (2a), P (2b), the Fe4E4skeleton of which consists of a triangulated dodecahedron. S8and gray Se oxidize the P2ligands of2bwith formation of [Cp4Fe4(P2X2)2], X = S (3a), Se (3b), complexes with the hitherto unknown P2X2ligands,2a, band3a, bhave been characterized by X‐ray crystallograph

ISSN:0009-2940    

DOI:10.1002/cber.19951281202

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractPentacarbonyltungsten‐coordinated selenobenzaldehyde, [(CO)5W{Se=C(Ph)H}] (1), reacts withtBu‐CC‐SMe (2) by insertion of the CC into the Se=C bond to form in a highly regio‐ and stereoselective manner the α,β‐unsaturated thioselonocarboxylic ester complex (Z)(C=C)‐[(CO)5W{1‐Se=C(SMe)C(tBu)=C(Ph)H}] (3). The thioselonocarboxylic ester ligand is cleaved intact from the metal by treatment of3with [NEt4]Br. Three complexes are formed in the reaction of1with Me‐CC‐SMe (5): the thioselonocarboxylic ester complex [(CO)5W{1‐Se=C(SMe)C(Me)=C(Ph)H}] (6) as a mixture of the (E) and (Z)(C=C) isomers, a selenetane complex (7) and a dihydrodiselenine complex (8). The product distribution depends on the ratio1:5and on the solvent. The reaction of1with the bis(organylthio)alkynes RS‐CC‐SR (9) [R = Me (a),iPr (b), 2,6‐C6H3Me2(c)] yields mixtures of the (E) and (Z)(C=C) isomers of the α,β‐unsaturated α‐organylthio thioselonocarboxylic ester complexes [(CO)5W{1‐Se=C(SR)C(SR)=C(Ph)H)] (10a‐c). In contrast, the reaction of1withtert‐butoxyethyne, H‐CC‐OtBu (11), affords a bis(pentacarbonyltungsten) 5,6‐dihydro‐1,2‐diselenine complex (12). Compound12is probably formed by consecutive reaction of1with11to give the selonocarboxylic ester complex [(CO)5W{1‐Se=C(OtBu)C(H)=C(Ph)H}] which then further reacts as a heterodiene by highly regioselective [4 + 2]cycloaddition with the Se=C bond of a second molecule of1to give12. In the reaction of1with5and9athe isomer with atransarrangement of C(=Se)SMe and Ph is the kinetically controlled reaction product [(E)‐6and (Z)‐10a, respectively]. The formation of (E)‐6and (Z)‐10ais followed by isomerization until an (E)/(Z) equilib

ISSN:0009-2940    

DOI:10.1002/cber.19951281203

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe 2‐metalation of enantiomerically pure (S)‐(2‐methoxy‐methylpyrrolidin‐1‐yl)ferrocene FcSMP (1) with BuLi proceeds with high diastereoselectivity (up to 98% de) to yield the Ph2P‐substituted ferrocene (S,Sp)‐2aafter quenching with Ph2PCl. The SMP moiety was removed by heating of2aat reflux in acetic anhydride to give planar chiral (Sp)‐2‐diphenylphosphanylferrocenylmethyl acetate (5). The diastereoisomer (S,Rp)‐2bwas synthesized from1by intermediately blocking the primary metalation site with a Me3Si group which can be removed afterwards by treatment with KOtBu in DMSO. Compound2awas treated with [(C3H5)PdCl]2to give the complex [(C3H5)Pd·2a]PF6(7·PF6). The structure of7·PF6was determined by a single‐crystal X‐ray diffraction study and showed2ato act as a

ISSN:0009-2940    

DOI:10.1002/cber.19951281204

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe facile formation of boron‐nitrogen bridges allows the one‐step assembly of oligonuclear organometallic complexes. By the reaction of 1‐(dibromoboryl)ferrocene (1a) and 1,1′‐bis(dibromoboryl)ferrocene (1b) with 1‐[(dimethylamino)methyl]ferrocene (2) and (η6‐aniline)tricarbonylchromium derivatives (3, 4) dinuclear to pentanuclear units (5–10) were obtained. The homodimetallic compound FcBBr2‐NMe2CH2Fc (5, Fc: ferrocene) closely resembles a propylene‐bridged complex. Its dative B‐N link is stable at temperatures as high as 100°C. Each of the heterooligonuclear aggregates7–10is tied together by covalent B‐N bonds, which are isoelectronic with ethylene bridges. In FcB(Br)‐N(Me)Bct [7, Bct: (η6‐C6H5)Cr(CO3)] and 1,1′‐Fc[B(Br)‐N(Me)Bct]2(9) B‐N π bonding dominates over the N‐Bct π interaction as indicated by spectroscopical data and an X‐ray analysis of9. TheN‐lithiated compounds BctNRLi (4a, b; R = H, Me) possess a remarkably increased N‐Bct π donation compared to the protonated parent compounds, which results in a further perturbation of t

ISSN:0009-2940    

DOI:10.1002/cber.19951281205

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe influence of a 5 M ethereal LiClO4solution as solvent on the addition of different alkyl Grignard and alkynyllithium reagents to highly enolizable ketones was studied. A comparison with the results in the presence of CeCl3shows a similar improvement in the yield.

ISSN:0009-2940    

DOI:10.1002/cber.19951281206

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe mononuclear dichloroosmium(II) complexes [(mes)‐Os(L)Cl2] (2‐5) with the phosphanyl ether L =iPr2PCH2‐CH2OMe and phosphanyl esters L =IPr2P(CH2)nCO2R as ligands are obtained from [(mes)OsCl2]nand L in almost quantitative yield. While compound3(L =iPr2PCH2CH2CO2Me) reacts with Mg/Hg in THF in the presence of ethanol to give the monohydrido derivative6, treatment of4(L =iPr2PCH2‐CO2Me) or5(L =iPr2PCH2CO2Et) with Al2O3/NaH in THF yields the phosphanylmethanide complexes [(mes)‐Os{k2(P,C)‐iPr2PCHCO2R}Cl] (7,8). In contrast to the reaction of4with Mg/Hg in THF/EtOH which yields the dihydrido compound [(mes)OsH2{k(P)‐iPr2PCH2CO2Me}] (10), the corresponding reaction of4with excess PhMgBr does not lead to an OsPh2species but instead gives the new chelate complex [(mes)OsPh{k2(P,O)‐iPr2PCH2CPh2O}] (11). The crystal and molecular structures of7and11

ISSN:0009-2940    

DOI:10.1002/cber.19951281207

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractPhenyllithium was labeled with6Li and13C at theipsocarbon atom, and the tetramer was measured by solid‐state NMR. The chemical shift tensor data were obtained by a moment analysis of the spinning side bands and were compared with the results obtained by calculations with the IGLO method. Although no splitting by dipolar spin coupling to6Li was found the very good agreement between IGLO predictions and experimental results allowed alignment of the tensor axis to the molecular frame and interpretation of the data. The large deshielding of the isotropic chemical shift is mainly due to a decrease of the ΔEterm in

ISSN:0009-2940    

DOI:10.1002/cber.19951281208

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe diboration of the diazene PhN = NSiMe3(15) by diborane(4) derivatives provides a new synthetic route toN,N'‐diborylated hydrazines. The product formed depends on the type of the diborane(4) compound. Thus, addition of dimesityldiboron dichloride to15in a 1:1 ratio afforded (mesCIB)PhN‐N(SiMe3)(BClmes) (16) while bis(dimethyl‐amino)diboron dichloride was found to react in a 1:2 ratio to give a triazadiborolidine derivative17. In addition, it was demonstrated that in the solid state Me2N–N(BPh2)2(8) is a derivative of a three‐membered dihydroazadiboriridineCwhile its isomer, (Ph2B)MeN–NMe(BPh2) (7), forms no BN coordinative bond. The new 3,6‐difluoro‐1,2,4,5‐tetraza‐3,6‐diborine13shows a twist conformation. The molecular structures of all these compounds were determined by X‐ray crystal structure analysis, and the influence of the B substituent on the co

ISSN:0009-2940    

DOI:10.1002/cber.19951281209

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractA mild and effective method for the preparation of aromatic and olefinic sulfonamides is described. The reaction of trialkylaryl‐ (4a–f), heteroaryl‐ (4g), and vinylic stannanes (4h) with sulfuryl chloride and secondary amines provides the corresponding sulfonamides in anipso‐specific

ISSN:0009-2940    

DOI:10.1002/cber.19951281210

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe synthesis and characterization of seven copper coordination compounds with the 14‐membered macrocycliccis‐N2S2dibenzo ligand 6,7,13,14,15,16,17,18‐octahydrodibenzo[e,m]‐[1,4,8,11]dithiadiazacyclotetradecine (L1) and itsN,N'‐bisacetato and ‐bis(methylpyridyl) functionalized derivatives H2L2and L3are described. The structures of five compounds were determined by single‐crystal X‐ray diffraction. The tetrahedrally distorted square‐planar coordination geometry of [CuL1](ClO4)2(1) changes upon reduction of copper to a severely distorted tetrahedral geometry in [CuL1]Br · MeCN (2). The Cu–N bond lengths increase from 1.988(3) to 2.029(5) Å; the Cu–S bond lengths decrease from 2.293(1) to 2.255(2) Å. Copper(II) is hexacoordinated in [CuHL2]HSO4· 2.5 H2O (5) and [CuHL2]ClO4· H2O (6). Both compounds exhibit very similar overall structures in the cationic part. The macrocyclic ring of the ligand is folded along an N ⃜S axis, the octahedral geometry is strongly Jahn‐Teller distorted, with O and S donor atoms in the apical positions. Compound5contains one very short [2.271(3) Å] and one long [2.701(3) Å]Cu–S (thioether) bond. In [CuL3](ClO4)2· 2 H2O (7) one thioether group of the ligand L3remains uncoordinated. The coordination polyhedron is rather irregular: Cu–S 2.506(3) and Cu–N 1.960(7)–2.107(8) Å. The compounds were further characterized by electronic and EPR spectroscopy and by cyclic voltammetry. Some relationships to the structural and spectroscopic prope

ISSN:0009-2940    

DOI:10.1002/cber.19951281211

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY