Design and Synthesis of Chiral Oxathiozinone Scaffolds: Efficient Synthesis of Hindered Enantiopure Sulfinamides and Sulfinyl Ketimines

摘要

Chiral-sulfinamide-mediated (1; see Scheme 1) chemistry has become one of the most employed approaches for the synthesis of compounds containing chiral amine functionalities.Moreover, their utility has been extended to being used as chiral ligands for many catalytic asymmetric transformations.Although the potential of chiral sulfinamides has long been recognized, only a few methods have been developed for their synthesis. Among the prominent works are the method reported by Davis et al. for the synthesis of p-toluenesul-finamide (pTSA) from Anderson's reagent, the method reported by Ellman and co-workersfor the synthesis of tert-butanesulfinamide (tBSA) from tert-butyl tert-butane-thiosulfinate, and others. However, these methods cannot meet the demand for accessing sulfinamides with diverse structures, which are required to fine-tune stereoselectivities in asymmetric synthesis. To meet this need, soon after the report from the group of Ellman, we designed and developed a versatile cyclic-oxathiozolidinone-based chiral sulfinyl-transfer agents which provide access to a range of sulfinamides with diverse structures (Scheme 1).