Organocatalytic enantioselective direct vinylogous Michael addition of γ-substituted deconjugate butenolides to azadienes

Abstract

The diastereoselective and enantioselective direct vinylogous Michael addition of γ-substituted β,γ-unsaturated γ-lactones to 2-arylidene-<italic>N</italic>-tosylbenzofuran-3(2<italic>H</italic>)-imines has been achieved with the aid of a quinine-derived squaramide.