Enantioselective cross-dehydrogenative coupling enabled by organocatalysis

Abstract

Oxidative cross-dehydrogenative coupling (CDC) reactions offer an attractive option for the direct formation of C–C and C–X (X = heteroatom) bonds because there is no need for prefunctionalization of substrates. Due to the atom-economical nature, these reactions are considered environmentally friendly. While nonasymmetric CDC reactions have been extensively explored, asymmetric versions are still underdeveloped. In recent years, asymmetric CDC reactions have gained significant attention, particularly in the field of organocatalysis. In this regard, several distinct activation modes of organocatalysis have been developed, and successfully applied to the asymmetric CDC reactions for the construction of chiral molecules via the formation of C–C and C–X bonds under oxidative conditions. In addition, the incorporation of cooperative strategies, such as the combination of organocatalysis with transition metal catalysis, photocatalysis, and electrocatalysis, can further expand the scope of organocatalytic enantioselective CDC reactions. In this review, recent progress in enantioselective CDC reactions catalyzed by organocatalysts is summarized. The entire review is categorized by reaction type, and the proposed mechanisms and prospects are also discussed.