Magnesium catalyzed [3 + 3] heteroannulation of α-enolic dithioesters with MBH acetate: access to functionalized 3,4-dihydro-2H-thiopyrans

Abstract

Magnesium catalysis proved to be efficient towards [3 + 3] chemo- and diastereoselective heteroannulation employing racemic Morita–Baylis–Hillman (MBH) acetate as the C3 unit and α-enolic dithioester as the C2S1 unit, leading to highly substituted 3,4-dihydro-2H-thiopyrans in excellent yields. The compatibility with a wide range of functional groups makes this domino formation of C–C and C–S bonds interesting. DFT analyses for the regioselective formation of the intermediate was performed.