When Hydrazonoyl Chlorides Meet Terminal Alkynes: Regioselective Copper(I)-Catalysed "Click" Sequential Reactions to 5-Substituted Pyrazoles
作者:Giorgio Molteni
DOI:10.3987/com-20-14268
日期:——
In the presence of catalytic amounts of copper(I) salts, terminal alkynes underwent the formation of copper(I) acetylides that enabled their nucleophilic addition onto hydrazonoyl chlorides followed by spontaneous cyclisation of the resulting alkynylhydrazone intermediate. This sequential reaction sequence was exploited as a facile and regioselective synthesis of 1,3,5-substituted pyrazoles. A catalytic
When Aryldiazonium Salts Meet Vinyl Diazoacetates: A Cobalt-Catalyzed Regiospecific Synthesis of <i>N</i>-Arylpyrazoles
作者:Haiheng Guo、Daming Zhang、Chenghao Zhu、Jian Li、Guangyang Xu、Jiangtao Sun
DOI:10.1021/ol5012339
日期:2014.6.6
A cobalt-catalyzed C-N bond formation between aryl diazonium salts and vinyl diazoacetates has been developed under relatively mild conditions. The N-arylpyrazoles have been prepared in moderate to high yields in a regiospecific way.