Visible-light-promoted N–H functionalization of O-substituted hydroxamic acid with diazo esters
作者:Shuangshuang Xia、Yongchan Jian、Liwen Zhang、Cheng Zhang、Yuanyuan An、Yubin Wang
DOI:10.1039/d3ra02407e
日期:——
Herein we report an N–H functionalization of O-substituted hydroxamic acid with diazo esters under blue LED irradiation conditions. The present transformations could be performed efficiently under mild conditions without use of catalyst, additive and N2 atmosphere. Interestingly, when THF and 1,4-dioxane were employed as the reaction solvents, an active oxonium ylide involved three-component reaction
在此,我们报道了在蓝色 LED 照射条件下 O-取代异羟肟酸与重氮酯的 N-H 官能化。在不使用催化剂、添加剂和 N 2气氛的情况下,本转化可以在温和条件下有效地进行。有趣的是,当使用 THF 和 1,4-二恶烷作为反应溶剂时,活性氧鎓叶立德分别涉及三组分反应和卡宾物种向异羟肟酸酯中的 N-H 插入。
One-Step Synthesis of <i>O</i>-Benzyl Hydroxamates from Unactivated Aliphatic and Aromatic Esters
[GRAPHICS]We have developed a simple and high yielding one-step method for the synthesis of hydroxamate derivatives directly from a broad range of unactivated esters and the anion of O-benzyl-hydroxylamine generated in situ. The reaction takes place in minutes at -78 degrees C. Very importantly, the method was successfully employed with enolizable esters, including chiral alpha-amino acid esters and peptides, with no trace of racemization/epimerization at the a carbon detected.