Benzylic aroylation of toluenes with unactivated tertiary benzamides promoted by directed ortho-lithiation
作者:Can-Can Bao、Yan-Long Luo、Hui-Zhen Du、Bing-Tao Guan
DOI:10.1007/s11426-021-1035-5
日期:2021.8
amides and highly reactive organometallic reagents bring great challenges for an efficient and selective synthetic approach. Herein, we reported an lithium diisopropylamide (LDA)-promoted benzylic aroylation of toluenes with unactivated tertiary benzamides, providing a direct and efficient synthesis of various aryl benzyl ketones. This process features a kinetic deprotonative functionalization of toluenes
甲苯的去质子官能化,由于酸性较弱,一般需要强碱,因此条件要求苛刻,会产生副产物。酰胺与有机金属试剂的直接亲核酰基取代反应可以为酮合成提供理想的解决方案。然而,惰性酰胺和高反应性有机金属试剂为高效和选择性的合成方法带来了巨大挑战。在此,我们报道了二异丙基酰胺锂 (LDA) 促进的甲苯与未活化的叔苯甲酰胺的苄基芳酰化,提供了各种芳基苄基酮的直接有效合成。该过程具有甲苯的动力学去质子官能化和易于获得的基础 LDA。机制研究表明,定向叔苯甲酰胺与 LDA 的邻位锂化促进了甲苯的苄基动力学去质子化,并引发了与酰胺的亲核酰基取代反应。