Solid support catalysts intramolecular reaction

Zeolites have also known as efficient catalysts for a wide variety of acid-promoted cyclization reactions. Most of them involves the formation of N-heterocycles through the intramolecular amination reaction pathway [48-50]. See examples are shown in Figure 11.13. Pyridines are also being produced by the reaction of ammonia over solid support acid catalyst with various aldehydes [50]. 

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