Palladium(II)-catalyzed oxidative C-H/C-H coupling and eliminative S _N ~H reactions in direct functionalization of imidazole oxides with indoles

摘要

Two novel synthetic approaches to realize the direct C(sp ~2)-H bond functionalization in cyclic nitrones are reported. Palladium(II)-catalyzed oxidative C-C coupling of 2,2-dialkyl-4-phenyl-2H-imidazole 1-oxides with indoles was shown to result in the formation of 5-indolyl-3-yl derivatives, while nucleophilic substitution of hydrogen (S _N ~H) at C(5) of the same imidazole system was found to afford the corresponding deoxygenated compounds.