Air-Tolerant Direct Thiol Esterification with Carboxylic Acids Using Hydrosilane via Simple Inorganic Base Catalysis
作者:Maojie Xuan、Chunlei Lu、Meina Liu、Bo-Lin Lin
DOI:10.1021/acs.joc.9b00500
日期:2019.6.21
thioesterification of carboxylicacids with thiolsusing nontoxic activation agents is highly desirable. Herein, an efficient and practical protocol using safe and inexpensive industrial waste polymethylhydrosiloxane as the activation agent and K3PO4 with 18-crown-6 as a catalyst is described. Various functional groups on carboxylicacid and thiol substituents can be tolerated by the present system to afford thioesters
非常需要使用无毒的活化剂将羧酸与硫醇直接硫酯化。在此,描述了一种有效且实用的方案,该方案使用安全且廉价的工业废聚甲基氢硅氧烷作为活化剂,并以18-crown-6作为催化剂的K 3 PO 4。本系统可以耐受羧酸和硫醇取代基上的各种官能团,从而以19-100%的收率提供硫酯。
A Practical Synthesis of β-Keto Thioesters by Direct Crossed-Claisen Coupling of Thioesters and N-Acylbenzotriazoles
作者:Don Coltart、Guoqiang Zhou、Daniel Lim、Fang Fang
DOI:10.1055/s-0029-1216971
日期:2009.10
Thioesters undergo chemoselective soft enolization and acylation with N-acylbenzotriazoles on treatment with MgBr2ËOEt2 and i-Pr2NEt to give β-keto thioesters. Prior enolate formation is not required and the reaction is conducted using untreated dichloromethane open to the air.