Copper-Mediated Synthesis of Substituted 2-Aryl-N-benzylbenzimidazoles and 2-Arylbenzoxazoles via C-H Functionalization/C-N/C-O Bond Formation

Murali Mohan Guru, Md Ashif Ali and Tharmalingam Punniyamurthy*

*Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati-781039, India, Email: tpunniiitg.ernet.in

M. M. Guru, M. A. Ali, T. Punniyamurthy, J. Org. Chem., 2011, 76, 5295-5308.

DOI: 10.1021/jo2005632

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Abstract

An efficient method for the transformation of N-benzyl bisarylhydrazones and bisaryloxime ethers to functionalized 2-aryl-N-benzylbenzimidazoles and 2-arylbenzoxazoles involves a copper(II)-mediated cascade C-H functionalization/C-N/C-O bond formation under neutral conditions. Substrates having either electron-donating or -withdrawing substituents undergo the cyclization at moderate temperature.

see article for more examples

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Ligand-Free Copper-Catalyzed Synthesis of Substituted Benzimidazoles, 2-Aminobenzimidazoles, 2-Aminobenzothiazoles, and Benzoxazoles

P. Saha, T. Ramana, N. Purkait, M. A. Ali, R. Paul, T. Punniyamurthy, J. Org. Chem., 2009, 74, 8719-8725.

Copper(II)-Catalyzed Conversion of Bisaryloxime Ethers to 2-Arylbenzoxazoles via C-H Functionalization/C-N/C-O Bonds Formation

M. M. Guru, M. A. Ali, T. Punniyamurthy, Org. Lett., 2011, 13, 1194-1197.

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Key Words

benzimidazoles, benzoxazoles

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ID: J42-Y2011-1830