A N-heterocyclic carbene derived highly regioselective ambident C-C-S and C-C-N 1,3-dipolar system.
N-Heterocyclic carbene derived 2-phenylthiocarbamoyl benzimidazolium and imidazolinium inner salts are a unique ambident C-C-S and C-C-N 1,3-dipolar system able to undergo highly efficient and regioselective cycloaddition with dimethyl acetylenedicarboxylate and ethyl propiolate to furnish, respectively, spiro[imidazole-2,3'-thiophene] and spiro[imidazole-2,3'-pyrrole] derivatives in good to excellent yields.
Liu
Mei-Fang
MF
Chemistry Department, Beijing Normal University, Beijing 100875, China.
Wang
Bo
B
Cheng
Ying
Y