Site-selective halogenation on meso-mesityl substituents of 10,20-dimesityl-5,15-diazaporphyrins with an AuX3/AgOTf combination

We have developed site-selective bromination on the mesityl substituents of 10,20-dimesityl-5,15-diazaporphyrins. Treatment of 10,20-dimesityl-5,15-diazaporphyrin and its nickel(II) complex with a combination of AuBr3/AgOTf induced selective bromination on the mesityl groups. These brominated products can be employed for late-stage modification of the aryl substituents.