The intramolecular nitrile oxide cycloaddition (INOC) reaction is applied to the synthesis of novel isoxazolooxazepinoindazole, benzoisoxazolodiazepinoindazolone, and spiro[isoxazoloazepine]piperidine heterocycles. Each of these targets incorporates a unique trinitrogen-containing triheterocyclic framework. alkenes - cycloadditions - heterocycles - pericyclic reactions - spiro compounds