Copper-Catalyzed Diversity-OrientedSynthesis (DOS) of 4-Amino-2H-chromen-2-imines:Application of Kemp Eliminationtoward O-Heterocycles

摘要

We report herein a copper-catalyzed sequential multicomponent reaction of benzo[d]isoxazoles with terminal alkynes and sulfonyl azides, which produced divergent 4-amino-2H-chromen-2-imines with excellent chemical selectivity. The reaction tolerated a broad range of functional groups, and released only N2 as the sole byproduct. The sulfonyl imino group could be removed to give biologically active free 4-amino-2H-chromenone in good yield.