Preparation of 5-Substituted 1H-Tetrazoles Catalyzed by Scandium Triflate in Water

Abstract

Several 5-substituted 1H-tetrazoles were prepared in water or isopropanol/water mixtures using microwave heating. Good yields were obtained for the [2 + 3] cycloaddition of sodium azide with aryl nitriles, aliphatic nitriles, and vinyl nitriles when catalyzed by scandium triflate. The reactions were typically heated for 1 h at 160 °C in a 3:1 isopropanol/water mixture to obtain the best yields.

GRAPHICAL ABSTRACT

Keywords:

• [2 + 3] Cycloaddition
• microwave
• scandium triflate
• 5-substituted 1H-tetrazoles
• water

Notes

^a 8 mmol of NaN₃ and 0.4 equiv of Sc(OTf) ₃ .xH₂O were used with nitrile 1h.

^a 8 mmol of NaN₃ and 0.4 equiv of Sc(OTf) ₃ .xH₂O were used with nitrile 1s.