Some reactions of the platinum(II) carbene complex cis-dichloro(dimethylaminomethylene)(triphenylphosphine)platinum(II) and the X-ray crystal and molecular structures of the products trans-(CH2,P)-chloro(chloromethyl)(dimethylaminomethylene)(tripheny

摘要

The reaction of the title complex 1 with excess diazomethane results in the exclusive insertion of a methylene group into the Pt-Cl bond trans to the phosphine ligand, to give the chloromethyl complex 6. The reactions of 1 with the diphosphines, Ph2P(CH2)nPPh(2)(n = 2, dppe, n = 3, dppp), and with the organometallic reagents Ph4Sn, Ph2Hg, or PhSnMe3, can also all be interpreted as proceeding via initial displacement of the chlorine trans to PPh3. The chelating phosphine ligands give equilibrium mixtures of the products [(LL)Pt(CHNMe2)(PPh3)](2 +)2Cl(-) and [(LL)Pt(CHNMe2)Cl]Cl+- (LL = dppe, dppp), and treatment of the mixture [(LL)= dppe] with excess aqueous KPF6 gave [(dppe)Pt(CHNMe2)PPh3)](2+) 2PF(6)(-) (9b). The insertion product (Ph3P)Pt(CHPhNMe2)Cl (11) was isolated from the reaction of 1 with PhSnMe3. This complex undergoes further reaction upon standing in CDCl3 solution, giving various products including benzaldehyde, N,N-dimethylbenzylamine, cis- and trans(Ph3P)Pt(NHMe2)Cl-2, and the new carbene complex cis-(Ph3P)Pt[C(Ph)NMe2]Cl-2 (17). Mechanisms are suggested for the formation of these products. The structures of chloromethyl complex 6 and hexafluorophosphate salt 9b have been determined by X-ray crystallography. (C) 2001 Published by Elsevier Science B.V. [References: 24]