Carbene B−H Insertion Reactions for C−B Bond Formation

Abstract Carbene B−H insertion reactions represent an efficient method for C−B bond formation, which have experienced great advances in recent years. Free and metal carbene insertion into B−H bonds based on diazo and nondiazo carbene precursors, including α‐diazoesters, α‐diazoketones, hydrazones, chloroforms, acylsilanes, alkenyl triflates, alkynes and sulfoxonium ylides have been well studied. The development of this chemistry complements existing C−B bond formation strategies in terms of substrate scope, selectivity and product diversity. Notably, the catalytic enantioselective carbene B−H insertion reactions enable easy access to the challenging but important chiral organoboron compounds. This review provides a timely overview on this research topic. Typical achievements in reaction methodologies, plausible reaction mechanisms, as well as applications in the synthesis of bioactive molecules are summarized.