Substituent-Controllable Cascade Regioselective Annulation of β-Enaminones with N-Sulfonyl Triazoles for Modular Access to Imidazoles and Pyrroles
作者:Hua Wang、Tongtong Zhou、Mengdi Wu、Qingqing Ye、Xinwei He
DOI:10.3390/molecules28114416
日期:——
A controllable synthesis of trisubstituted imidazoles and pyrroles has been developed through rhodium(II)-catalyzed regioselective annulation of N-sulfonyl-1,2,3-trizaoles with β-enaminones. The imidazole ring was formed through a 1,1-insertion of the N-H bond to α-imino rhodium carbene, followed by a subsequent intramolecular 1,4-conjugate addition. This occurred when the α-carbon atom of the amino
通过铑 (II) 催化的 N-磺酰基-1,2,3-三唑与 β-烯胺酮的区域选择性环化,开发了三取代咪唑和吡咯的可控合成。咪唑环是通过将 NH 键 1,1-插入到 α-亚氨基铑卡宾上,随后进行分子内 1,4-共轭加成而形成的。这发生在氨基的 α-碳原子带有甲基时。此外,吡咯环是通过利用苯基取代基并进行分子内亲核加成而构建的。温和的条件、对官能团的良好耐受性、克级合成能力以及对产品进行有价值的转化的能力使这一独特的协议成为合成 N-杂环的有效工具。