A [bmim]Cl-promoted domino protocol using an isocyanide-based [4+1]-cycloaddition reaction for the synthesis of diversely functionalized 3-alkylamino-2-alkyl/aryl/hetero-aryl indolizine-1-carbonitriles under solvent-free conditions

A domino protocol involving aldehydes, isocyanides and 2-pyridylacetonitrile in the presence of [bmim]Cl as a promoter and solvent for the synthesis of 3-alkylamino-2-alkyl/arylindolizine-1-carbonitriles is described. A wide range of alkyl, aryl and hetero-aryl aldehydes reacted with 2-pyridylacetonitrile and isocyanides, leading to indolizine derivatives with high selectivity, high atom economy, and good to excellent yields. This straight-forward and highly efficient method allows the synthesis of bis-indolizine-1-carbonitrile derivatives. A room temperature-based ionic liquid [bmim]Cl-catalyzed multicomponent coupling strategy for the synthesis of 3-alkylamino-2-alkyl/aryl/hetero-aryl indolizine-1-carbonitrile derivatives under mild conditions is shown.