Copper(I)-Catalyzed [3 + 2] Cycloaddition/Ring-Opening Rearraegement/[4+2]Cycloaddition/Aromatization Cascade: An Unprecedented Chemo-and Stereoselective Three Component Coupling of Sulfonyl Azide, Alkyne and N-Arylidenepyridin-2-amine to Pyrido[1,2-a]pyrimidin-4-imine

摘要

A novel synthetic protocol for the one-pot chemo-and stereoselective construction of diversely functionalized pyrido[1,2-a]pyrimidin-4-imines via copper(I)-catalyzed [3+2]cycloaddition/ ring-opening rearrangenent/[4+2] cycloaddition/ar-omatization cascade of sulfonyl azides, alkynes and N-arylidenepyridin-2-amines under mild reaction conditions is reported. In addition, the catalytic activity of copper(I)-modified zeolite, a recyclable, heterogeneous catalyst is also investigated, which gives improved yield compared to its homogeneous equivalents.