Regioselective SN' allylic substitution versus 1,4-addition: Synthesis of α-substituted β,γ-unsaturated esters

Article abstract of DOI:10.1016/S0040-4039(00)70708-8

The reaction of the higher order organocuprate reagents R₂Cu(CN)Li₂-BF₃ with γ-bromo α,β-unsaturated esters gives with very high selectivity α-substituted β,γ-unsaturated esters arising from a SN' allylic substitution. This reaction allows an easy access to α-silyl β,γ-unsaturated esters.