Reactions and properties of some trimethyleneplatinum(IV) complexes. Part 11. Platinacyclobutanes derived from methylcyclopropane

Abstract

It is shown that platinacyclobutanes derived from methylcyclopropane exist as a mixture of isomers with partial structures [graphic omitted]H₂ and [graphic omitted]HMe, and that these isomers interconvert easily. In some cases decomposition of these platinacyclobutanes gives ylide complexes [PtCl₂{CH(L)CH₂CH₂Me}L], e.g. L = 2-methylpyridine, while in other cases but-1-ene complexes [PtCl₂(CH₂CHCH₂Me)L], e.g. L = CD₃CN, are formed. In both cases the products are formed selectively from the least stable isomer of the platinacyclobutane. At higher temperatures or on photolysis, platinacyclobutane complexes such as [PtCl₂(C₃H₅Me)(1,10-phenanthroline)] decompose to give but-1-ene, 2-methylpropene, propene, and ethylene and the relative yields depend on the experimental conditions. Possible mechanisms are discussed.