Cobalt(III) hydride HAT mediated enantioselective intramolecular hydroamination access to chiral pyrrolidines

Abstract

Enantioenriched pyrrolidines and derivatives are ubiquitous substructures in compounds of importance to medicinal and biological chemistry. Herein, we report an efficient cobalt-catalyzed intramolecular asymmetric hydroamination reaction that produces chiral pyrrolidines with good to excellent yield and enantiocontrol. Compared with previously reported radical-involved methodologies for enantioenriched pyrrolidines, these conditions feature two elegant versatilities, enabling (1) the use of cobalt-catalyzed hydrogen atom transfer (HAT) to generate organocobalt intermediates that bring radical reaction to organometallic chemistry, and (2) enantioselective intramolecular C–N bond forging through an S_N2-like displacement involving dynamic kinetic resolution (DKR). This approach provides a new alternative and efficient methodology for enantioselective radical-involved C–N bond construction that can be used in the synthesis of both chiral pyrrolidines and homologous nitrogen heterocycles.