Three-Component Reaction of Isocyanides and 2-Formylbenzoic Acid with Dibenzylamine Catalyzed by Silica Nanoparticles under Solvent-Free Conditions

Reaction of an isocyanide with an iminium ion intermediate, formed by reaction between 2-formylbenzoic acid and dibenzylamine in the presence of silica nanoparticles NP, ca 42 nm) proceeds smoothly at room temperature to afford isocoumarin (=1H-2 benzopyran-1-one) derivatives in high yields (Scheme I and Table I)