Enantioselective intramolecular Morita-Baylis-Hillman reaction using chiral bifunctional phosphinothiourea as an organocatalyst

摘要

Chiral cyclohexane-based phosphinothioureas were found to be efficient organocatalysts for the enantioselective intramolecular Morita-Baylis-Hillman reaction of ω-formyl-enone. Among the solvents screened, t-BuOH was the best one which provided good yield and enantioselectivity. Moreover in the presence of 3 mol % of phosphinothiourea 2b, the desired products were obtained in good-to-excellent yields with up to 98% ee under mild reaction conditions.