Polymer-Supported Dibutylstannyl Azide: An Efficient and Recoverable Reagent in the One-Pot Synthesis of Aryl Azides and 5-Aryl 1H-tetrazoles

Herein, a very stable and highly reactive insoluble polymer-supported organotin azide was prepared from a Merrifield resin and its azide loading was determined by elemental analysis. This immobilized azide was employed in one-pot diazotization-azidodediazoniation of aromatic amines to provide a wide range of aryl azides in very good yields under mild conditions. On the other hand, this supported reagent was successfully applied in the 1,3-dipolar cycloaddition reaction with aromatic nitriles to provide 5-aryl 1H-tetrazoles in good yields. In addition, the recyclability of tin azide from the supported dibutyltin sulfonate recovered in the synthesis processes was reported. The developed methods allow the recycling and reuse of the supported tin azide, without significant loss of reactivity after four cycles in our reaction scale and less than 20 ppm of residual tin concentration in final products without additional purification.

Keywords:
polymer-supported organotin azide; aryl azides; azidodeamination; 5-aryl 1H-tetrazoles; 1,3-dipolar cycloaddition