Isonicotinate Ester Catalyzed Decarboxylative Borylation of (Hetero)Aryl and Alkenyl Carboxylic Acids through <i>N</i>-Hydroxyphthalimide Esters
作者:Wan-Min Cheng、Rui Shang、Bin Zhao、Wei-Long Xing、Yao Fu
DOI:10.1021/acs.orglett.7b01950
日期:2017.8.18
Decarboxylative borylation of aryl and alkenyl carboxylic acids with bis(pinacolato)diboron was achieved through N-hydroxyphthalimide esters using tert-butyl isonicotinate as a catalyst under base-free conditions. A variety of aryl carboxylic acids possessing different functional groups and electronic properties can be smoothly converted to aryl boronate esters, including those that are difficult to
芳基和链烯基羧酸与双(频哪醇合)二硼的脱羧硼化通过实现Ñ使用-hydroxyphthalimide酯叔异烟酸丁酯在无碱条件下作为催化剂。可以将具有不同官能团和电子特性的各种芳基羧酸平稳地转化为芳基硼酸酯,包括在过渡金属催化下难以脱羧的芳基硼酸酯,从而提供了一种新方法,使羧酸可以用作有机合成中的基础。机理分析表明,该反应通过自由基脱羧产生的瞬态芳基与吡啶稳定的持久性硼基的偶联而进行。氧化还原活性酯的活化可以通过分子内单电子转移(SET)过程,通过吡啶-二硼-邻苯二甲酰亚胺加合物进行,并说明了无碱反应条件。