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

Abstract

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