Abstract
The N–H-benzimidazole directing group (DG)–assisted transition metal (TM)–catalyzed
C(sp2)–H activation and annulation reaction emerged as a powerful strategy for the synthesis
of benzimidazole-based organic compounds, natural products and late-stage functionalization.
This account highlights the recent advancements made in rhodium- and palladium-catalyzed
C–H activation/annulation reactions on the benzimidazole core developed over the past
decades. These strategies have facilitated the formation of C–C, C–N, C–O, and C–F
bonds through Rh- and Pd-catalyzed cross-coupling annulation. A diverse array of diazo,
alkynes, maleimides, olefins, ylides and aryl halides were used as the coupling partners
to achieve C–H annulation. This review summarizes benzimidazole-based synthetic strategies,
highlighting the substrate scope, key mechanistic insights and the nature of the coupling
partners.
Keywords
Carbenes - Combinatorial chemistry - Cross-coupling - Cycloaddition - Diazo compounds