Catalytic enantioselective construction of quaternary stereocenters by direct vinylogous Michael addition of deconjugated butenolides to nitroolefins.

A direct vinylogous Michael reaction of γ-substituted deconjugated butenolides with nitroolefins has been developed with the help of a newly identified quinine-derived bifunctional catalyst, allowing the synthesis of densely functionalized products with contiguous quaternary and tertiary stereocenters in excellent yield with perfect diastereoselectivity (>20:1 dr) and high enantioselectivity (up to 99:1 er). This journal is © The Royal Society of Chemistry 2012