Facile access to polymer supported zinc–salen complex: highly efficient heterogeneous catalyst for synthesizing hydantoins, thiohydantoins and Schiff bases in aqueous medium
synthesized PS-Zn–salen complex used as a recyclable heterogeneous catalyst for the efficient synthesis of hydantoins, thiohydantoins and Schiffbases in an aqueous medium. The isolated yields of hydantoins, thiohydantoins and Schiffbases achieved up to 89, 95 and 94%, respectively. In spite of conventional heterogeneous catalysts, current PS-Zn–salen complex shows thermal stability up to 280 °C. Moreover