Synfacts 2010(2): 0158-0158  
DOI: 10.1055/s-0029-1219119
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart ˙ New York

Copper Nanoparticle Catalyzed Synthesis of Benzimidazoles, -oxazoles and -thiazoles

Contributor(s): Victor Snieckus, Toni Rantanen
P. Saha, T. Ramana, N. Purkait, M. A. Ali, R. Paul, T. Punniyamurthy*
Indian Institute of Technology Guwahati, India
Further Information

Publication History

Publication Date:
21 January 2010 (online)

Significance

The presented procedure expands on the research of the same group on ligand-free CuO nanoparticle catalyzed coupling of aryl iodides with sulfur, oxygen, and nitrogen nucleophiles (T. Punniyamurthy and co-workers J. Org. Chem. 2009, 74, 1971). The procedure is utilized in the synthesis of benzannulated heterocycles, benzimidazoles, benzoxazoles, and benzothia­zoles starting from bromo- or iodoaryl derivatives. Chloro derivatives (X = Cl) did not function at all, and neither did attempted CH activation reactions (X = H). Yields are mostly very good, with three exceptions in the synthesis of benzothiazoles being below 50% (Y = S, R² = Ar). The substrate scope was exhaustively studied, with over 50 examples reported.