CuI nanoparticles: A highly efficient catalyst for expedient and mild synthesis of dihydrochromeno[b]chromenone derivatives

A novel and practically useful protocol is described for the synthesis of dihydrochromeno[b]chromenone derivatives, by a coupling reaction of salicylaldehydes with 4-hydroxycoumarin catalyzed by copper (I) iodide nanoparticles (CuI NPs) as an efficient heterogeneous catalyst in green media-water.