Palladium-catalysed oxidative nucleophilic allylation between alkenes and activated ketimines

Abstract

While electrophilic allylation with alkenes under oxidative palladium catalysis has been well explored, its umpolung nucleophilic allylation version under identical conditions has not been disclosed. Here we report that the direct and linear regioselective allylation reaction between alkenes and activated ketimines can be realised by using the classical Pd(OAc)₂/2,6-dimethyl-1,4-benzoquinone (2,6-DMBQ) system, probably via the isomerisation of η³-π-allylpalladium complexes to η¹-allylpalladium species in the absence of additional nucleophilic reagents. Diverse control and deuterium experiments have been conducted to elucidate the catalytic mechanism.