Pd‐Catalyzed P–C Cross‐Coupling of Aryl Bromides and Triflates with Hydroxymethylphosphine Sulfide Derivatives

The development of a versatile process for phosphine synthesis has attracted considerable interest because organophosphines are indispensable for organic synthesis. Previously, we developed a Pd‐catalyzed P–C coupling reaction for hydroxymethylphosphine sulfide derivatives with various aryl iodides as a method for preparing a variety of triarylphosphine derivatives. However, the catalyst system for aryl iodides did not activate aryl bromides and triflates, which are more readily available than aryl iodides. Herein, we report a new and effective catalyst system for the P–C coupling of various aryl bromides and triflates with hydroxymethylphosphine sulfides. An application of the new method was demonstrated with the sequential synthesis of an unsymmetrically substituted triarylphosphine sulfide by using multiple couplings of an orthogonally protected precursor.