Iron(III)-promoted oxidative coupling of naphthylamines: synthetic and mechanistic investigations.

A facile route to the synthesis of 1,1'-binaphthyl-4,4'-diamines (naphthidines) and 1,1'-binaphthyl-2,2'-diamines (BINAMs) was developed by the oxidative homocoupling of 1- and 2-naphthylamines, respectively, using FeCl(3) as oxidant and K(2)CO(3) as base in 1,2-dichloroethane under ambient conditions. A preliminary mechanistic investigation was performed by the ESR spectroscopy and intermediate-trapping technique.