Electron-withdrawing cocatalyst in rhodium catalyzed hydroformylation reactions. Ligand precatalyst for Heck coupling reactions. Reactant for: Preparation of palladium chiral P-N ligand complexes for regio- and stereo-selective dimerization reactions. Preparation of palladium tautomeric ferrocenylphosphinites as catalysts for Suzuki-Miyaura coupling. Trimethylsilyl halide-promoted Michaelis-Arbuzov rearrangement of phosphinites and phosphites.