Rh(II)-catalysed N 2 -selective arylation of benzotriazoles and indazoles using quinoid carbenes via 1,5-H shift.

An efficient Rh(II)-catalyzed highly selective N 2 -arylation of benzotriazole, indazole, and 1,2,3 triazole is developed using diazonaphthoquinone. The developed protocol is extended with a wide scope. In addition, late-stage arylation of these scaffolds tethered with bioactive molecules is explored. Control experiments and DFT calculations reveal that the reaction proceeds presumably via nucleophilic addition of the N 2 (of the 1 H tautomer) center to quinoid-carbene followed by a 1,5-H shift.