Copper-Promoted One-Pot Sandmeyer-Type Reaction for the Synthesis of N-Aryltriazoles
Menghan Cui, Rong Wang, Qing Yang and Chunxiang Kuang*
*Shanghai Key Lab of Chemical Assessment and Sustainability,
School of Chemical Science and Engineering, Tongji University, Shanghai 200092,
China, Email: kuangcx
tongji.edu.cn
M. Cui, R. Wang, Q. Yang, C. Kuang, J. Org. Chem., 2022, 87, 9654-9662.
DOI: 10.1021/acs.joc.2c00697
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Abstract
Diazonium salts, formed from aromatic amines and tert-butyl nitrite in the presence of fluoroboric acid, reacted with triazoles in a copper-catalyzed Sandmeyer-type reaction under mild conditions to afford N-aryltriazoles in good yields. This method is amenable to a wide range of aromatic amines and triazoles and shows diverse functional group tolerance.
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proposed mechanism
Details
The article discusses a novel copper-catalyzed one-pot Sandmeyer-type reaction for synthesizing N-aryl-1,2,3-triazoles from aromatic amines and triazoles. The process involves forming diazonium salts from aromatic amines and tert-butyl nitrite in the presence of fluoroboric acid, which then react with triazoles in a copper-catalyzed reaction. This method operates under mild conditions and yields N-aryltriazoles in moderate to good yields, demonstrating broad functional group tolerance. The reaction mechanism suggests a radical pathway, where aryl radicals, copper, and triazoles form a complex that undergoes reductive elimination to produce aryltriazole compounds. This approach offers a valuable alternative for constructing C−N bonds and synthesizing aryltriazole derivatives, which are significant in medicine, pesticides, synthetic chemistry, and materials sciences. The method is advantageous over traditional click reactions and cycloaddition reactions, which often involve hazardous azides and harsh conditions. The study also explores the reaction's substrate scope, showing good yields with various functionalized arylamines and triazoles. The findings highlight the potential of this method for further applications in synthesizing aromatic C−N bonds and triazole compounds.
Key Words
Sandmeyer reaction, 1,2,3-triazoles, benzotriazoles, N-arylation
ID: J42-Y2022
