Reactions of platinum complexes with alkyl-substituted cyclopropanes. The formation of platinacyclobutanes

Abstract

Mono-, di-, and tri-alkyl-substituted cyclopropanes react with certain platinum complexes to form platinacyclobutanes, tetrakis[dichloro(substituted-cyclopropane)platinum]. These products result from insertion of platinum into the least-substituted carboncarbon bond of the cyclopropane ring. Although the stereochemistry of insertion is compatible with steric control of the reaction, evidence is presented for dominant electronic control, with platinum behaving as a nucleophile in the actual insertion step. Formation of these compounds, and their subsequent chemical reactions, appear to be competitive with rearrangement to platinumolefin complexes.