Phenylselanyl-1H-1,2,3-triazole-4-carbonitriles: synthesis, antioxidant properties and use as precursors to highly functionalized tetrazoles

We describe herein our results on the synthesis, antioxidant properties and chemical diversification of phenylselanyl-1H-1,2,3-triazole-4-carbonitriles. These compounds were synthesized in high yields by the reaction of azidophenyl phenylselenides with a range of alpha-keto nitriles, using DMSO as the solvent in the presence of a catalytic amount of Et2NH (1 mol%). The synthesized compounds were screened for their in vitro antioxidant activity and 5-phenyl-1-(2-(phenylselanyl) phenyl)-1H-1,2,3-triazole-4-carbonitrile (3a) exhibited the highest antioxidant effect. In addition, the obtained triazoyl carbonitriles were readily transformed into more complex products via a cycloaddition protocol with NaN3, affording bifunctional hybrids containing triazole and tetrazole systems in good to excellent yields.