Copper-Catalyzed Oxidation of Hydrazones to Diazo Compounds Using Oxygen as the Terminal Oxidant,ACS Catalysis

当前位置： X-MOL 学术 › ACS Catal. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Copper-Catalyzed Oxidation of Hydrazones to Diazo Compounds Using Oxygen as the Terminal Oxidant
ACS Catalysis ( IF 11.3 ) Pub Date : 2021-02-12 , DOI: 10.1021/acscatal.1c00264
Wenbin Liu ₁ , Jack Twilton ₂ , Bo Wei ₁ , Maizie Lee ₁ , Melissa N. Hopkins ₂ , John Bacsa ₁ , Shannon S. Stahl ₂ , Huw M. L. Davies ₁

Affiliation

A mild method for accessing diazo compounds via aerobic oxidation of hydrazones is described. This catalytic transformation employs a Cu(OAc)₂/pyridine catalyst and molecular oxygen from ambient air as the terminal oxidant, generating water as the sole byproduct and affording the desired diazo compounds within minutes at room temperature. A broad array of electronically diverse aryldiazo esters, ketones, and amides can be accessed. Pyridine dramatically enhances the rate of the reaction by solubilizing the copper catalyst and serving as the Brønsted base in the turnover-limiting proton-coupled oxidation of hydrazone by copper(II). Insights gained from mechanistic studies led to expansion of the scope of this method to include diaryl hydrazones, delivering diaryl diazomethane derivatives, which cannot be accessed via established diazo transfer methods. The products of this method may be employed in rhodium carbene catalysis without isolation of the diazo intermediate to afford cyclopropane products in good yield with high enantioselectivity.

中文翻译：

以氧为末端氧化剂的铜催化of氧化为重氮化合物

描述了一种通过的好氧氧化访问重氮化合物的温和方法。该催化转化采用Cu（OAc）₂吡啶催化剂和来自周围空气的分子氧作为末端氧化剂，生成水作为唯一的副产物，并在室温下在数分钟内提供所需的重氮化合物。可以使用各种各样的电子形式的芳基重氮酯，酮和酰胺。吡啶通过溶解铜催化剂并在Br的营业额限制质子偶联的-（II）氧化中充当布朗斯台德碱，大大提高了反应速率。从机理研究中获得的见识导致该方法的范围扩大到包括二芳基，并提供了二芳基重氮甲烷衍生物，而这是通过既定的重氮转移方法无法获得的。

更新日期：2021-03-05

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南