Catalytic Intramolecular Acylsulfenylation of Activated Alkenes: Enantioselective Synthesis of 3,3-Disubstituted Quinoline-2,4-diones

An asymmetric intramolecular acylsulfenylation approach is presented. By combining catalytic amount of chiral amino diether (1S,2S)-L6 and RSLi, a wide range of 3,3-disubstituted quinoline-2,4-dione derivatives incorporating all-carbon quaternary stereocenters could be accessed in excellent yields and enantioselectivities in a catalytically atom-economic fashion. The concept relies on an asymmetric SMA/aldol type sequence by employing thioester as a bifunctional carbonyl resource, which enabled the construction of the cyclic scaffolds smoothly.