A simple, metal- and ligand-free procedure for the Ullmann-type C–O coupling reactions has been achieved by allowing aryl bromides to react with a variety of phenols in the presence of t-BuOK. Moderate to excellent yields of O-arylation products are obtained under mild conditions in a short time. In addition, two examples of C–N coupling reactions are also reported. A benzyne mechanism is proposed
Combination of formamide and cyanuric chloride afforded a new combined “CN” source which is highly stable and safe and can be used in organic cyanation transformation reactions instead of common cyanide sources. This study unfolds the efficient Pd‐catalyzedcyanation of aryl halides using TCT‐formamide reagent as a new combined “CN” source.
Copper-catalyzed <i>O</i>-arylation of phenols with diazonium salts
作者:Xin Fang、Chengning Qi、Xiangqian Cao、Zhi-Gang Ren、David James Young、Hong-Xi Li
DOI:10.1039/d3gc02541a
日期:——
It is well known that diazonium salts (ArN2+) react with phenols (Ar′OH) to give aryl diazoethers or diazo compounds, but their cross-coupling to exclusively access diaryl ethers is challenging. Herein we disclose the Cu-catalyzed etherification of phenols with aryl diazonium salts at room temperature, yielding diaryl ethers in moderate to excellent yields. The advantages of this protocol are mild