γ-Selective allylic substitution reaction with Grignard reagents catalyzed by copper N -heterocyclic carbene complexes and its application to enantioselective synthesis
The reaction of allylic compounds with alkyl Grignard reagents in the presence of a catalytic amount of copper N-heterocyclic carbene (NHC) complexes proceeded predominantly in an SN2′ reaction pathway to give γ-substituted product in excellent yield. The method was applied to asymmetric reaction by using optically active NHC ligands.
Alkenylfluorosilanes smoothly underwent cross-coupling reaction with allylic carbonates in the presence of a palladiun catalyst and in the absence of fluoride ion to give 1,4-dienes in good yields with retention of configuration.