Transition-Metal-Free α Csp -H Cyanation of Sulfonamides.

This report describes the site-selective α-functionalization of sulfonylamide derivatives through the in-situ generation of imine intermediates. The N-F sulfonylamides, which could facilitate the elimination to generate imines, are coupled with TBACN to efficiently and mildly afford α-amino cyanides. Comparing with Strecker reaction, this transformation offers a complementary strategy to efficiently construct α-amino cyanides from direct α C-H functionalization of sulfonylamindes. The reaction is also characterized by broad substrate scope and flash chromatography column free workup. More importantly, the new two-electron pathway to generate imines through manipulation of the leaving group allows us to achieve excellent α site-selectivity.