Ligand-Free Copper-Catalyzed Synthesis of Substituted Benzimidazoles, 2-Aminobenzimidazoles, 2-Aminobenzothiazoles, and Benzoxazoles
Prasenjit Saha, Tamminana Ramana, Nibadita Purkait, Md Ashif Ali, Rajesh Paul and Tharmalingam Punniyamurthy*
*Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati-781039, India, Email: tpunniiitg.ernet.in
P. Saha, T. Ramana, N. Purkait, M. A. Ali, R. Paul, T. Punniyamurthy, J. Org. Chem., 2009, 74, 8719-8725.
DOI: 10.1021/jo901813g
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Abstract
An experimentally simple, general, efficient, and ligand-free synthesis of substituted benzimidazoles, 2-aminobenzimidazoles, 2-aminobenzothiazoles, and benzoxazoles via intramolecular cyclization of o-bromoaryl derivatives is catalyzed by copper(II) oxide nanoparticles in DMSO under air. The heterogeneous catalyst can be recovered and recycled without loss of activity.
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M. M. Guru, M. A. Ali, T. Punniyamurthy, J. Org. Chem., 2011, 76, 5295-5308.
Key Words
ID: J42-Y2009-3340