A N-heterocyclic carbene derived highly regioselective ambident C–C–S and C–C–N 1,3-dipolar system
作者:Mei-Fang Liu、Bo Wang、Ying Cheng
DOI:10.1039/b517700f
日期:——
N-Heterocyclic carbene derived 2-phenylthiocarbamoyl benzimidazolium and imidazolinium inner salts are a unique ambident CâCâS and CâCâN 1,3-dipolar system able to undergo highly efficient and regioselective cycloaddition with dimethyl acetylenedicarboxylate and ethyl propiolate to furnish, respectively, spiro[imidazole-2,3â²-thiophene] and spiro[imidazole-2,3â²-pyrrole] derivatives in good to excellent yields.
由 N-杂环碳烯衍生的 2-苯基硫代氨基甲酰苯并咪唑鎓和咪唑啉鎓内盐是一种独特的 CâCâS 和 CâCâN 1、3 双极体系,能够与乙酰二甲酸二甲酯和丙炔酸乙酯发生高效和区域选择性环加成反应,分别生成螺[咪唑-2,3â²-噻吩]和螺[咪唑-2,3â²-吡咯]衍生物,收率良好甚至极佳。