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

A Rh-catalyzed [5 + 1] cycloaddition reaction for the synthesis of spirocyclicindoline imine from 3-diazoindolin-2-imine with benzo[d]isoxazole is reported. The reaction proceeds under gentle catalytic conditions, thus giving the expected spiro[benzo[e][1,3]oxazine-2,3'-indolin]-2-imines with good functional-group tolerance. Scheme 1. Synthesis of spirocyclicindolines through metallo carbenoid protocols.