Dehydrative amination of benzhydrols with electron-withdrawing group-substituted 2-aminopyridines utilizing Au(iii)/TPPMS catalyst system in water

We report a method for gold(iii)/sodium diphenylphosphinobenzene-3-sulfonate (TPPMS)-catalyzed direct amination of benzhydrols using 2-aminopyridines with poor nucleophilic character in water. Various functional groups such as electron-withdrawing nitro, cyano and halogen groups were tolerated well to form the desired N-benzylated 2-aminopyridine compounds. On the basis of mechanistic studies including kinetic profiles, Hammett study and isotope effects, we propose a pathway in which a Lewis acidic gold cation species activates the sp3 C–O bond of the alcohol in the rate-determining step.