Convenient and Efficient Palladium-Catalyzed Coupling Reaction Between Ferroceneboronic Acid and Organic Triflates

A simple and efficient palladium (Pd)-catalyzed Suzuki cross-coupling reaction between ferroceneboronic acid and organic triflates for the preparation of monosubstituted ferrocene derivatives has been developed. A systematic study of various solvents, bases, and catalysts revealed that the combination of Pd(PPh3)4 (0.025 equiv) and K3PO4 (2 equiv) in refluxing dioxane gave reproducible and excellent yields of the coupling products. The reaction could be applied to a wide variety of aryl and vinyl triflates in good to excellent yields, and the electronic and steric effects were observed for ortho-, meta-, and para-substituents of aryl triflates.