Visible-light driven regioselective synthesis of 1H-tetrazoles from aldehydes through isocyanide-based [3 + 2] cycloaddition

A novel and green Co@g-C3N4 catalyzed visible light driven direct regioselective synthesis of 1H-tetrazoles directly from various aldehydes and sodium azide is reported. Herein, NaN3 not only behaves as a three-nitrogen donor of the tetrazole ring but also it converts aldehyde into isocyanide as a one-nitrogen source. The regioselectivity of the product, operational simplicity, ambient reaction conditions, no use of column chromatography for purification, excellent yield of products (84–95%) and recyclability of the catalyst up to five times without any substantial change in the morphology and catalytic efficiency are the salient features of the envisaged protocol.