Pd-Catalyzed Coupling of Thioamides with <i>N</i>-Tosylhydrazones/Trapping by Esters Cascade Reaction
作者:Zhongliang Cai、Zhi Yao、Liqin Jiang
DOI:10.1021/acs.orglett.0c03796
日期:2021.1.15
N,N-Disubstituted thioamides coupled with N-tosylhydrazones under Pd(TFA)2/tBuXPhos catalyst and NaOtBu, and the intermediates from palladium carbene migratory insertion containing β-hydrogen were trapped by intramolecular esters activated by BF3·Et2O instead of undergoing β-H elimination, providing polyfunctional thiophen-3(2H)-ones with sulfur-containing tetrasubstituted carbon centers in moderate
在Pd(TFA)2 / t BuXPhos催化剂和NaO t Bu催化下,N,N-二取代硫代酰胺与N-甲苯磺酰coupled偶合,以及含β-氢的钯卡宾迁移插入的中间体被BF 3 ·Et 2活化的分子内酯捕获。O代替β- H消除,提供多官能噻吩-3(2H含硫四取代碳原子的α-酮,产率中等至良好。该反应具有一次操作即可形成三个键,无味,安全且易于获得的底物,广泛的底物范围和出色的官能团耐受性的特点。