Pd-P(t-Bu)₃-Catalyzed Cross-Coupling of Silanes with Aryl Halides

Significance

This is the first report of a successful cross-coupling reaction of trialkylsilanes with aryl halides. Trialkoxysilanes, which possess a weaker reducing ability, have already been involved in this reaction. The proper choice of the ligand (a bulky electron-rich phosphine) and of the reaction condition allowed to suppress, at least in some cases, the reduction pathway and to achieve good yield of aryl trialkylsilanes. Still, the reaction can be applied only to electron-rich aryl iodides. Electron-withdrawing groups on the ring or an ortho-substitution lead preferentially to the product of halide reduction. Nevertheless, the method is synthetically useful and it is a significant contribution in the field of cross-coupling reactions.