Diazo transfer reaction to 1,3-dicarbonyl compounds with sulfonyl azides catalyzed by molecular sieves

A simple and effective heterogeneous catalyst based on zeolite-type materials has been developed for the diazo transfer reaction involving 1,3-dicarbonyl compounds and tosyl azide. a-Diazo carbonyl compounds were obtained under mild conditions in good to high yields using commercial molecular sieve 4A or analogues as the catalyst. The best catalyst was found to be 4A-1000, a synthetic potassium-free nepheline obtained by heating molecular sieve 4A at 1000 degrees C. Characterization of the resulting aluminosilicate by XRD, FTIR and SEM-EDS analysis confirmed the change of the crystal structure. Besides being nontoxic and inexpensive, the heterogeneous catalyst was readily removed by filtration and could be reused at least for four runs without any special treatment.(C) 2014 Elsevier B.V. All rights reserved.