An efficient approach to (E)-β-methyl Baylis–Hillman adducts via indium-mediated allylation of aldehydes in aqueous media

Abstract

A new method has been developed for the synthesis of (E)-β-methyl Baylis–Hillman adducts with high E–Z (>93%) selectivity in modest to good yields. The process consists of two steps: an indium-mediated allylation reaction and a simple base-catalyzed isomerization step. Various aldehydes were allylated with allyl bromides using indium under very mild conditions in aqueous media. The allylation reactions of aromatic and aliphatic aldehydes were largely accelerated by the presence of HCl.