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

摘要

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