Transition-metal-free [3+2] cycloaddition of C,N-cycloazomethylimines with in situ formed isocyanates from dioxazolones: a facile synthesis of triazolinones

A novel strategy for synthesizing triazolinone with C , N -cycloazomethylimine and dioxazolone has been developed, in which the isocyanate formed in situ from dioxazolone is employed for cyclization instead of the widely used N -acyl nitrene.