Dirhodium-Catalyzed Transannulation of<i>N</i>-Sulfonyl-1,2,3-triazoles to 2,3-Dehydropiperazines
作者:Michael J. Nutt、Jack W. Annear、Kieran D. Jones、Gavin R. Flematti、Stephen A. Moggach、Scott G. Stewart
DOI:10.1021/acs.joc.3c01259
日期:2023.8.18
dirhodium(II)-catalyzed synthesis of a range of C2-substituted 2,3-dehydropiperazines using 1-mesyl-1,2,3-triazoles and β-haloalkylcarbamates is reported. The reaction is proposed to proceed through an α-imino rhodium carbene 1,3-insertion into N–H followed by a base-mediated cyclization. C-Substituted dehydropiperazines can also be conducted directly from terminal alkynes in a three-step, one-pot operation, forming
据报道,使用 1-甲磺酰基-1,2,3-三唑和 β-卤代烷基氨基甲酸酯,二铑 (II) 催化合成了一系列 C2 取代的 2,3-脱氢哌嗪。该反应通过 α-亚氨基铑卡宾 1,3-插入 N-H 进行,然后进行碱介导的环化。C-取代的脱氢哌嗪也可以直接从末端炔烃以三步一锅操作进行,原位形成三唑。该方法也已得到扩展,可提供几种 2,5-二取代的 2,3-脱氢哌嗪以及更大的 4,5,6,7-四氢-1 H -1,4-二氮杂卓衍生物。