Photoinduced cobalt-catalyzed enantioconvergent synthesis of 1,3-diamines via aziridine ring-opening addition.

Abstract

Chiral amines are privileged scaffolds with pervasive importance across the organic synthesis. Nevertheless, the stereoselective construction of 1,3-diamines bearing multiple stereocenters represents a significant and persistent challenge in synthetic chemistry. Addressing this, we recognized aziridines as ideal yet underutilized precursors. While these readily available three-membered heterocycles are established building blocks for chiral amines synthesis via ring-opening substitutions, catalytic methods that directly engage them in enantioselective addition to electrophiles have remained elusive. Herein, we report a photoinduced, cobalt-catalyzed enantioconvergent addition of styrenyl aziridines to imines via radical ring-opening. This strategy enables direct and modular access to valuable 1,3-diamine scaffolds bearing vicinal stereocenters-including a tetrasubstituted carbon chiral center-with excellent stereocontrol (99% ee, >20:1 dr). The reaction proceeds via a completely regioselective ring-opening pathway involving a stabilized benzylic radical intermediate, avoids waste generation from radical precursors, tolerates a broad range of substrates, and requires no stoichiometric metal reductants.