Nucleophilic Aromatic Substitution of 5-Bromo-1,2,3-triazines with Phenols

Nucleophilic aromatic substitution (S Ar) reaction in classic textbook is a stepwise mechanism, and few examples of concerted reactions have been reported. Herein, we developed a concerted S Ar reaction of 5-bromo-1,2,3-triazines with phenols in which the nonclassic mechanism of this reaction could be revealed by calculation. Furthermore, the resulting 5-aryloxy-1,2,3-triazines could be used as convenient precursors to access biologically important 3-aryloxy-pyridines in one-pot manner.