Regioselective Annulation of 2-(2-Bromophenyl)-1 H-Imidazoles With Ortho-Substituted Phenylacetylenes Catalyzed by CuI

Abstract

The two-component reaction between 2-(2-bromophenyl)-1H-imidazoles and ortho-substituted phenylacetylenes was investigated under basic conditions catalyzed by CuI. High yields of 5-benzylidene-5H-imidazo[2,1-a]isoindoles were obtained via a 5-exo-dig reaction when the substituent was an electron-withdrawing group. Conversely, when the substituent was an electron-donating group, the reaction yielded 5-arylimidazo[2,1-a]isoquinolines through a 6-endo-dig process.