Boron Perturbed Click Reactions Prompt Aromatic CH Activations

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