Boron perturbed click reactions prompt aromatic C-H activations.

The reaction of boron alkynes and boron azides leads to rare N3BC heterocycles resulting from aromatic C-H activation of benzene and toluene. While subsequent treatment with PMe3 gave the P-B adduct with the exocyclic boron, reaction with PtBu3 effected deprotonation of the heterocycle to give the corresponding phosphonium salt.