Synthesis of Thieno[2,3-d]imidazoles by Copper-Catalyzed Amidine Cyclization

A new synthetic approach to thieno[2,3-d]imidazoles is presented on the basis of the N′-(3-halothiophen-2-yl)amidine cyclization under copper-catalyzed cross-coupling. Using commercially available starting materials such as 2-aminothiophenes or their Boc-protected derivatives and copper catalysts, this method offers a convenient route to a wide range of thieno[2,3-d]imidazole derivatives, especially the 5-alkyl-subtituted thieno[2,3-d]imidazoles.

Liubchak K.; Tolmachev A.; Nazarenko K.
Synlett 2014, 25 (07), 965-968
DOI: 10.1055/s-0033-1340959