摘要:

AbstractThis review deals with lanthanoid mediated organic reactions investigated by the authors. The scope of the lanthanoid‐mediated reactions are discussed under the following topics:(a)Reactions of Yb metal umpoled diaryl ketones with electrophiles;(b)Reactions of Yb metal with imines;(c)Reactions of Yb metal with CC multiple bonds;(d)Reactions of Sm metal with nitroarenes;(e)Reactions of Yb metal with α,β‐unsaturated carbonyl compounds;(f)Reactions of a PhYbI σ‐complex;(g)Reactions of LnCl3as Friedel‐Cra

ISSN:0268-2605    

DOI:10.1002/aoc.590040402

出版商:John Wiley&Sons Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractThis article comprehensively reviews the literature concerning the adducts formed between crown ethers and organotin(IV), inorganic tin(IV) and inorganic tin(II) species, and it also covers organotin(II) complexes containing alkali metal–crown ether cations. The uses of crown ethers as cocatalysts in organic and organotin synthesis are surveyed and some potential industrial applications of crown ether/tin chemical systems are discusse

ISSN:0268-2605    

DOI:10.1002/aoc.590040403

出版商:John Wiley&Sons Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe reactivity of isopropenylacetylene (IP) in the presence of [Ni(NCS){CCC(CH3)CH2}(PPh3)2] has been examined. 1,2,4‐Tris(isopropenyl)benezene (1,2,4‐TIB), two isomeric tetramers formed by reaction of 1,2,4‐TIB with IP, and polymeric fractions have been separated and characterized by IR, NMR and mass spectra. Stability of reaction products towards oxygen and humidity has also been

ISSN:0268-2605    

DOI:10.1002/aoc.590040404

出版商:John Wiley&Sons Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe mechanism of but‐1‐ene, pent‐1‐ene and 3‐methylbut‐1‐ene isomerization catalysed withtrans‐[PtH(SnX3)L2] (I, L = PPh3, PMePh2, PEt3, PPr3; X = Cl, Br) have been studied. Stoichiometric reactions of I with the alkenes proceed even at −90°C givingcis‐[Pt(alkyI‐1) (SnX3) L2] (II). The equilibrium amounts of II are dependent on the nature of the phosphines, halogens and alkenes. The isomerization rates, determined at +20°C, change in parallel with the relative stabilities of II as a function of phosphine (PMePh2>PPh3>PAlk3) and halogen (Br>Cl), and decrease with methyl substitution at γ‐ and δ‐ carbons of the alkenes. 2‐Substituted alk‐1‐enes undergo no isomerization in the reactions under investigation. When L is PPh3or PMePh2, the main platinum‐containing species in the course of the isomerization aretrans‐[Pt(alkyl‐1) (SnX3)L2], appearing as a result ofcis‐transisomerization of II. The conversion of I, L = PAlk3into relatedtrans‐alkyl complexes, and oxidation of I, proceed more slowly than the isomerization of alkenes. The ratio ofcis‐ totrans‐alk‐2‐enes is dep

ISSN:0268-2605    

DOI:10.1002/aoc.590040405

出版商:John Wiley&Sons Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe characterization by 1D and/or 2D1H NMR,13C NMR,119Sn NMR, Mössbauer and mass spectrometry of a series of di‐n‐butyltin derivatives of 3‐, 4‐, and 5‐methyl‐, 3‐, 4‐, and 5‐methoxy‐, 4‐ and 5‐amino‐substituted, and 3,5‐diiodo‐salicyclic acids is described. Their NMR spectra suggest that they are present as dimers in CDCl3solution, like the di‐n‐butyltin derivative of unsubstituted salicyclic acid. This has been confirmed by the observation of mixed dimers. The insoluble derivatives have been characterizerd by solid state cross polarization/magic angle spinning (CP/MAS)13C and/or119Sn NMR, Mössbauer and mass spectroscopy. These compounds are characterizedin vitroby a lower inhibition dose thancis‐platin or etoposide agai

ISSN:0268-2605    

DOI:10.1002/aoc.590040406

出版商:John Wiley&Sons Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe diphenyllead(IV) derivatives ofN‐benzoyl‐(glycine,DL‐alanine);N‐formyl andN‐acetyl‐L‐phenylalanine;N‐monochloroacetyl‐L‐phenylalanine;N‐benzoyl‐(glycylglycine,DL‐alanylglycine), andN‐formyl‐N‐acetyl‐ andN‐monochloroacetyl‐(L‐phenylalanylglycine) have been prepared in 1:2 molar ratio by reaction of diphenyllead dichloride with the appropriate amino‐acid or dipeptide. Corresponding triphenyllead(IV) derivatives have been prepared in 1:1 molar ratio by reaction of triphenyllead chloride with the thallium(I) salts of the amino‐acid or the dipeptide. These complexes have been characterized by elemental analysis, IR and1H NMR spectral studies. A polymeric hexacoordinated octahedral structure for diphenyllead(IV), and a five‐coordinated distorted trigonalbipyramidal chain‐type structure for triphenyllead(IV), complexes is confirmed by IR spectra. The carboxylate group acts in a bidentate manner, not as in diorgano and triorganotin(IV) complexes with these acids, where it is monodentate. The available bonding sites such as amide and peptide carbonyl (CO) and amide and peptide nitrogen atoms are not involved in bonding with lead (IV) and thus are available for bonding with the biological systems. The presence of differentN‐protecting groups does not affect the coordination sites around lead(IV). The triphenyllead(IV) compounds are relativel

ISSN:0268-2605    

DOI:10.1002/aoc.590040407

出版商:John Wiley&Sons Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractA large amount of data has appeared in the literature within the last few years dealing with the monitoring of butyltin compounds in coastal environments. However, the strategies used strongly differed from one author to another, which led to difficulties in the comparison of contamination levels and the evaluation of long‐term trends. In this paper, different causes of pitfalls due to uncontrolled sources of variability are addressed; they involve precautions to be undertaken for the monitoring of butylins in water and sediment, particularly: sample collection; sample pretreatment (filtration/centrifugation, acidification, sieving); sample storage (different methods for storage and drying procedures); variability over the same site; variations over a tidal cycle; and variability due to diffusion (e.g. due to flushing

ISSN:0268-2605    

DOI:10.1002/aoc.590040408

出版商:John Wiley&Sons Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractHydroformylation of propene was studied at 90–120°C and 3–10 atm. The catalyst was hydrido‐(carbonyl)tris(triphenylphosphine)rhodium [H(CO)Rh(PPh3)3] supported on silica, in an excess of a liquid phosphine (P) ligand as solvent. The following series of ligands (P) was synthesized and studied in this application: CH3(CH2)nPPh2(n= 3, 7, 17), (c – C6H11)xPPh3−x(x= 0, 1, 2) and also unsaturated allyl‐ and poly(butadienyl)‐diphenylphosphines. The activity and regioselectivity of the catalysts are discussed in terms of the mobility and coordination ability of the ligands used. With the same electron density of the phosphorus atom, the activity of the catalysts increases with the mobility of the ligands. On the other hand, given the same mobility of the ligand, a lower electron density on phosphorus results in increased cata

ISSN:0268-2605    

DOI:10.1002/aoc.590040409

出版商:John Wiley&Sons Ltd.    

年代:1990

数据来源: WILEY

摘要:

Abstract[Bis(aminomethyl)dimethylsilane]platinum(II) dichloride (1) was synthesized by a three‐step procedure. The antitumor activity of 1 was evaluated in the i.p. implanted mouse L1210 leukemia model. A 10 mg kg−1dose administered every fourth day for a total of three injections extended the median life span of the dying mice by at least 100% and resulted in 40–50% survivors (day 30) in two experiments corresponding to an approximate 6 log10reduction in tumor burden at the end of treatment. Compound 1 appeared at least as active as cisplatin under the testing protocols utilized. The closely related bis[aminomethyltrimethylsilane]platinum(II) dichloride complex was inactive in this mouse

ISSN:0268-2605    

DOI:10.1002/aoc.590040410

出版商:John Wiley&Sons Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractPolysorbate 80 (Tween 80) was used as an emulsifying agent for administering tri‐n‐butyltin chloride (TBTCl) to rats below, at and above the LD50for the compound. Tween 80 greatly enhanced the toxicity of the organotin compound. The LD50in the presence of Tween 80 (16% of the emulsion) is less than half of the LD50when the TBTCl was administered in corn

ISSN:0268-2605    

DOI:10.1002/aoc.590040411

出版商:John Wiley&Sons Ltd.    

年代:1990

数据来源: WILEY