Cobalt-Catalyzed Effective Access to Quinoxalines with Insights in Annulation of Terminal Alkynes and -Phenylenediamines.

Org Lett

Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, China.

Published: November 2022

A novel methodology for the annulation of terminal alkynes and -phenylenediamines by using a combination of a cobalt catalyst and oxygen as a terminal oxidant is reported. This method shows wide substrate scope and good functional group tolerance and provides a wide range of quinoxalines in good to high yields. The method is demonstrated by its gram-scale and broad potential applications. Furthermore, this protocol serves as a powerful tool for the late-stage functionalization of various complex bioactive molecules and drugs to provide a new class of molecules containing two distinct bioactive molecules directly linked. Detailed mechanistic studies reveal that the current reaction goes through a novel mechanism different from the previously reported glyoxal mechanism.

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http://dx.doi.org/10.1021/acs.orglett.2c03465DOI Listing

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