Recent advances in C–B bond formation by borylation with NHC–boranes

Organoboron compounds play a pivotal role in synthetic, pharmaceutical, and material chemistry due to their distinctive properties. Developing efficient, regioselective methods for C–B bond construction via borylation remains a challenging yet highly desirable research goal. In this review, we provide an overview of recent advancements in borylation reactions of alkenes, alkynes, arenes, diazo compounds, imines, amides, and isocyanides using NHC–boranes as the borylation reagents, facilitated by transition-metal catalysis, organocatalysis, photoredox catalysis, biocatalysis, and cooperative catalysis. The reaction parameters, generality and limitations of substrate scope, and typical reaction mechanisms are mainly discussed. This review summarises recent advances in C–B bond formation utilising B–H activation strategy of N -heterocyclic carbene borane with various borylation acceptors, including alkenes, alkynes, arenes, diazo compounds, imines, amides, and isocyanides.