Efficient synthesis of chiral benzofuryl β-amino alcohols via a catalytic asymmetric Henry reaction

Chiral beta-amino alcohol ligands were found effective for the copper(II)-catalyzed asymmetric Henry reaction of benzofuran-2-carbaldehydes with nitromethane, which led to the formation of (S)-enriched benzofuryl beta-nitro alcohols with satisfactory enantioselectivities (up to 98% ee). Using this catalytic protocol, bioactive (S)-benzofuryl beta-amino alcohols could be conveniently prepared in short steps.