2.16 Chromium-Catalyzed Cross Coupling and C—H Functionalization

Abstract The use of the earth-abundant group 6 metal chromium as a cost-effective alternative to precious metal catalysts has emerged as a useful tool in modern synthetic chemistry. Significant advances in the field of cross coupling and C—H functionalization with chromium catalysis have been achieved, providing cost-effective and selective strategies to form C—C bonds, usually under mild conditions. This chapter aims to highlight recent achievements in the arena of cross coupling and C—H functionalization that are catalyzed by chromium. It is organized based on the type of bond (chemically unactivated C—heteroatom and C—H bonds) involved in the catalytic coupling, and there is a focus on the discussion of possible mechanisms for insight into the design of robust chromium catalysts for the development of new coupling models and strategies.