Heterogeneous Copper-Catalyzed Cascade Three-Component Reaction Towards Imidazo1,2-apyridines: Efficient and Practical One-Pot Synthesis of Alpidem

摘要

abstract_textpThe heterogeneous cascade three-component reaction of 2-aminopyridines, aldehydes and terminal alkynes was achieved in toluene at 120 degrees C in the presence of 3-(2-aminoethylamino)propyl-functionalized MCM-41-immobilized copper(I) complex MCM-41-2 N-CuCl (5 mol) and copper(II) complex MCM-41-2N-Cu(OTf)(2) (5 mol), yielding a wide variety of imidazo1,2-apyridines in mostly good to excellent yields. These two heterogeneous copper catalysts can be facilely prepared via a simple procedure from readily available and inexpensive reagents, and recovered by filtration and recycled up to eight times with almost consistent activity./p/abstract_text