Here, an efficient and general method for the regioselective synthesis of diarylmethane-phosphonium salts will be presented via C–H alkylation. This method is based on a one pot of four-component coupling reaction of simple and commercially available starting materials. The utility of the diarylmethane-phosphonium salts building blocks was demonstrated by selective post-amination of the benzylic C–+P bond. This functionalization leads, for the first time, to varieties of amine reagents to provide bioactive diarylamines. Additionally, this method used as a powerful tool for late-stage diversification of drugs.1