Organocatalytic enantioselective tandem sulfa-Michael/aldol reaction to access dihydrothiopyran-fused benzosulfolane skeletons bearing three contiguous stereocenters

Chem Commun (Camb). 2020 Oct 21;56(82):12363-12366. doi: 10.1039/d0cc04840b. Epub 2020 Sep 15.

Abstract

The first organocatalytic diastereo- and enantioselective tandem sulfa-Michael/aldol reaction of 2-mercaptoindole-3-carbaldehydes and 2-mercaptobenzaldehydes with benzo[b]thiophene sulfones was developed. With multiple hydrogen-bonding thiourea as a catalyst, a wide range of polycyclic dihydrothiopyran-fused benzosulfolanes were smoothly obtained with excellent results (up to 99% yield, >20 : 1 dr and 99% ee) under mild reaction conditions.