Preparation of a palladium dimer with a cobalt-containing bulky phosphine ligand: Its application in palladium catalyzed Suzuki reactions

作者：Gan Ya Huei; Lee Han Cheng; Hong Fung E^*

来源：Polyhedron, 2006, 25(18): 3555-3561.

DOI：10.1016/j.poly.2006.07.005

• palladium dimer
• Suzuki reaction
• transition-metal containing phosphine ligand
• orthometallation

A palladium dimer with a cobalt-containing phosphine ligand, {(mu-PPh2CH2PPh2)CO2(CO)(4)(mu,eta-(tBu)(2)PC CC6H4-kappa C-1)Pd(mu-Cl)}(2) (3), was prepared from the reaction of its monomer precursor, (mu-PPh2CH2PPh2)Co-2(CO)(4)(mu,eta-(tBu)(2)PC CC6H4-kappa C-1)Pd(mu-OAc) (2), with LiCl. The crystal structure of 3, determined by X-ray diffraction methods, revealed a doubly chloride-bridged palladium dimeric conformation. Suzuki coupling reactions of bromobenzene with phenylboronic acid were carried out catalytically using these two novel palladium complexes 2 and 3 as catalyst precursors. Factors such as the molar ratio of substrate/catalyst, reaction temperature, base and solvent that might affect the catalytic efficiencies were investigated. As a general rule, the performance is much better by employing 3 than 2 as the catalyst precursor.

• 出版日期2006-12-25