Taming of Thioketones: The First Asymmetric Thia‐Diels–Alder Reaction with Thioketones as Heterodienophiles

Abstract

An efficient application of aryl and hetaryl thioketones as dienophiles in the enantioselective thia‐Diels–Alder reaction was explored for the first time. It was found that thioketones could serve as useful heterodienophiles in aminocatalytic, trienamine‐mediated [4+2] cycloadditions with 2,4‐dienals. This enantioselective approach (up to 99:1 er) was efficiently promoted by diarylprolinol silyl ethers and led to new types of potentially relevant 5,6‐dihydro‐2H‐thiopyrans.