Copper-Catalyzed Construction of Benzo[4,5]imidazo[2,1-<i>a</i>]isoquinolines Using Calcium Carbide as a Solid Alkyne Source
Haiyan Liu, Zheng Li
Abstract
A method for the synthesis of benzo[4,5]imidazo[2,1-a]isoquinolines through Sonogashira cross-coupling/nucleophilic addition tandem reactions using calcium carbide as a solid alkyne source, 2-(2-bromophenyl)benzimidazoles as starting materials, and copper as a catalyst is described. The target products can also be synthesized through one-pot three-component reactions of o-phenylenediamines, o-bromobenzaldehydes, and calcium carbide. Both reaction routes can also be scaled up to gram scale.
Topics & Concepts
Calcium carbideAlkyneChemistrySonogashira couplingCatalysisNucleophileCombinatorial chemistryCopperCalciumCarbideOrganic chemistryPalladiumCatalytic C–H Functionalization MethodsCatalytic Alkyne ReactionsSynthesis and Biological Evaluation