Aerobic Coupling of Organophosphonium Salts with Alkenes: Catalyst-Free C(sp³)−C(sp²) Bond Formation

An aerobic coupling of benzhydryl phosphonium salts with simple alkenes for accessing trisubstituted olefins is developed under metal-free, catalyst-free, and additive-free conditions. New C(sp³)−C(sp²) bond is constructed via the C−P and C−H bond functionalization by synergistically using O₂ as a “green” oxidant and DMSO as a promoter. The method also distinguishes itself by its broad substrate scope and synthetic potential. Particularly, the use of 1,3,5-trimethoxybenzene fragment in the resulting products as a carbon-based leaving group for further transformations is proved to be feasible.