Organic Chemistry Portal



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:

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

DOI: 10.1021/jo901813g (free Supporting Information)

see article for more reactions


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.

see article for more examples

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

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

Key Words

Benzimidazoles, Benzoxazoles

ID: J42-Y2009-3340