Silica supported lanthanum triflate mediated synthesis of 5-substituted-1H tetrazoles

Silica supported lanthanum triflate (Ln(OTf)3-SiO2) promoted synthesis of 5-substituted 1H-tetrazoles via [3+2] cycloaddition between aromatic/heteroaromatic nitriles and sodium azide is a high product yielding, facile, and straightforward procedure. Non toxicity, recovery, and reusability for three continuous cycles are the noteworthy features of the currently employed heterogeneous catalyst.