Cobalt/Salox‐Catalyzed Enantioselective C−H Functionalization of Arylphosphinamides

Abstract

Previous methods on CoIII‐catalyzed asymmetric C−H activation rely on the use of tailor‐made cyclopentadienyl‐ligated CoIII complexes, which require lengthy steps for the preparation. Herein, we report an unprecedented enantioselective C−H functionalization enabled by a simple cobalt/salicyloxazoline (Salox) catalysis. The chiral Salox ligands can be easily prepared in one step from salicylonitrile and chiral amino alcohols. A broad range of P‐stereogenic compounds were synthesized in high yields with excellent enantioselectivities (45 examples, up to 99 % yield and >99 % ee). The isolation and characterization of several intermediates provided insights into the generation of active catalytic cobalt species, the action of Salox, and the mode of stereocontrol.

Enantioselective cobaltaelectro-catalyzed C–H activations enabled by hydrogen evolution

“…1B). (22)(23)(24)(25) In sharp contrast, the use of Earth-abundant 3d transition metals (26)(27)(28)(29)(30)(31)(32)(33)(34) in enantioselective electrocatalytic C-H activation has thus far unfortunately proven elusive. Given these major restrictions, we questioned whether enantioselective electrocatalytic C-H activation could be accomplished with 3d transition metal catalysts which typically proceed via single electron transfer (SET) elementary steps.…”