Reactions of Imidazoles with Electrophilic Metal Alkyl Complexes

The C−C coupling of two molecules of 1-methylbenzimidazole was effected by neutral yttrium and lutetium benzyl complexes supported by a 1,1′-ferrocenylene-diamide ligand. This transformation involves the C−H activation and coupling of one η2(N,C)-imidazolyl fragment with a coordinated 1-methylbenzimidazole ligand. The coupled product can be transformed into a mono- or dinuclear product, in which one of the imidazole rings is cleaved. Variable-temperature 1H and 2H NMR spectroscopic data support the reversibility of the C−C coupling event and explain the formation of the dinuclear product.