Cu2O-catalyzed Ullmann-type reaction of vinyl bromides with imidazole and benzimidazole

Cu2O was found to be an efficient and economical metal catalyst in the Ullmann cross-coupling reaction of vinyl bromides with imidazole or benzimidazole. The system Cu2O/ethyl 2-oxocyclohexanecarboxylate showed high catalytic activity in MeCN at 80-90 °C. The reaction gave the corresponding coupling products in good to excellent yields.

Cu2O was found to be an efficient and economical metal catalyst in the Ullmann cross-coupling reaction of vinyl bromides with imidazole or benzimidazole. It showed high catalytic activity with the ligand ethyl 2-oxocyclohexanecarboxylate in MeCN at 80-90 °C and gave the corresponding products in good to excellent yields. The double bond geometry of the vinyl bromides was retained under the reaction condition.