Indium(III) Chloride Catalyzed Synthesis of 5-Substituted 1H-Tetrazoles from Oximes and Sodium Azide

A simple and efficient protocol has been developed for the synthesis of 5-substituted 1 H -tetrazole derivatives in good to excellent yields from various oximes and sodium azide by using indium(III) chloride as a Lewis acid catalyst. The present method has significant advantages, such as an inexpensive catalyst, low catalyst loading, mild reaction conditions, and simple experimental procedures.