Enantioselective C−H functionalization reactions enabled by cobalt catalysis

Abstract

Enantioselective functionalization of C–H bonds offers a powerful solution and transformative tool for the step- and atom-economical construction of chiral molecular complexity. However, for a long time, this area was dominated by 4d and 5d transition metal catalysts. Recently, cobalt, as a 3d transition metal and group 9 metal, has earned considerable attention. Indeed, enantioselective C−H functionalization reactions enabled by cobalt catalysis have progressed rapidly in the past decade. In this review, we provide an overview of recent progress on cobalt-catalyzed enantioselective C−H functionalization reactions, including synthetic strategies, reactivities, selectivities, proposed mechanisms, and potential upcoming opportunities. Cobalt-catalyzed enantioselective C−H functionalization reactions have progressed rapidly in the past decade. In this context, cobalt catalysis not only emulates the similar but more expensive 4d/5d metal catalysis but also exhibits unique reactivities. However, compared with 4d/5d metal catalysis, cobalt-catalyzed enantioselective C−H functionalization reactions are underdeveloped in terms of synthetic strategies, reactivities, selectivities, chiral catalytic modes, and intrinsic mechanisms. In this review, we provide an overview of recent progress and potential upcoming opportunities on cobalt-catalyzed enantioselective C−H functionalization reactions. Enantioselective functionalization of C–H bonds offers a powerful solution and transformative tool for the step- and atom-economical construction of chiral molecular complexity. Recently, cobalt, as a 3d transition metal and group 9 metal, has earned considerable attention. Herein, we summarize and discuss four representative catalytic modes of cobalt catalysis, thus expecting to increase the interest of researchers in related fields and promote further developments in this area.