作者:Tanno A. Schmidt、Benjamin Ciszek、Prasad Kathe、Ivana Fleischer
DOI:10.1002/chem.202000251
日期:2020.3.18
investigations show that the substrate undergoes rearrangement to an aldehyde under [1,2]-H-migration and cleavage of an oxygen-based leaving group. The leaving group is trapped as its formic ester, and the aldehyde is reduced and subsequently esterified to a formate. While the rearrangement to the aldehyde is catalyzed by sulfonic acids, the reduction step requires a unique catalyst system comprising
在本文中,我们描述了酸/ Pd串联催化的乙二醇衍生物向末端甲酸酯的转化。机理研究表明,在[1,2] -H迁移和氧基离去基团的裂解下,底物发生重排成醛。离开的基团被捕获为其甲酸酯,醛被还原并随后酯化为甲酸酯。磺酸可催化醛的重排,而还原步骤则需要独特的催化剂体系,该体系包含Pd(II)-或Pd(0)-前体,其负载量低至0.75 mol%和a,a'-bis(二叔丁基膦基)-邻二甲苯作为配体。还原步骤利用甲酸作为易于处理的转移还原剂。