Asymmetric Synthesis of Chiral Sulfoximines through the S-Alkylation of Sulfinamides

Innovation in drug discovery critically depends on the development of new bioisosteric groups. Chiral sulfoximines, which contain a tetrasubstituted sulfur atom that bears one nitrogen, one oxygen, and two different carbon substituents, represent an emerging chiral bioisostere in medicinal chemistry. Chiral sulfoximines are conventionally prepared by a stereospecific nitrene transfer reaction to chiral sulfoxides; however, the number of readily available chiral sulfoxides remains limited. Herein, we report the asymmetric synthesis of a class of hitherto difficult-to-access chiral sulfoximines with two structurally similar alkyl chains. Our synthetic approach is based on the sulfur-selective alkylation of easily accessible chiral sulfinamides with commercially available reagents under simple and safe conditions. This stereospecific S-alkylation offers a general and scalable approach to the asymmetric synthesis of chiral sulfoximines, which represent important substructures in bioactive molecules.