Amination and Suzuki coupling reactions catalyzed by palladium complexes coordinated by cobalt-containing monodentate phosphine ligands with bis-trifluoromethyl substituents on bridged arylethynyl: Observation of some unusual metal-containing compounds

作者：Huang Po Cheng; Hong Fung E^*

来源：Journal of Organometallic Chemistry, 2009, 694(1): 113-121.

DOI：10.1016/j.jorganchem.2008.10.005

• Suzuki-Miyaura cross-coupling reaction
• Amination reaction
• Phosphine ligand
• Electron-withdrawing substituent
• Palladium-cobalt bond
• Palladium cluster

Two cobalt-containing bulky monodentate phosphines {[(mu-PPh(2)CH(2)PPh(2))Co(2)(CO)(4)][(mu, eta- (t)Bu)(2)PC CAr]} (4cm: Ar = 3-CF(3)C(6)H(4); 4cmm: Ar = 3,5-(CF(3))(2)C(6)H(3)) were prepared from the reaction of Co(2)(CO)(6)(mu-PPh(2)CH(2)PPh(2)) (3) with each corresponding alkynes ((t)Bu)(2)PC CAr. Both compounds were converted to their oxidized forms {[(mu-PPh(2)CH(2)PPh(2))Co(2)(CO)(4)][(mu, eta-((t)Bu)(2)P(=O) C CAr]} (4cmO: Ar = 3-CF(3)C(6)H(3); 4cmmO: Ar = 3,5-(CF(3))(2)C(6)H(3)) in the presence of oxide. Further reactions of 4cm and 4cmm with Pd(OAc)(2) gave palladium complexes {[(mu-PPh(2)CH(2)PPh(2))Co(2)(CO)(4)][(mu, eta-((t)Bu)(2)PC C(Ar)kappa C(1))] Pd(mu-OAc)} 5cm (Ar = 3-CF(3)C(6)H(3)) and 5cmm (Ar = 3,5-(CF(3))(2)C(6)H(2)), respectively. By contrast, reactions of 4cm and 4cmm with Pd(COD)Cl(2) gave products, [{mu-P, P-PPh(2)CH(2)PPh(2)}Co(2)(CO)(3)( mu-CO){mu, eta-((t)Bu)(2)PC CAr}]-PdCl(2)] 8cm and 8cmm, respectively, with unique bonding modes. Several crystallines of [(4cm)(2)Pd(3)(mu-Cl)(mu-CO)(2))(mu-Cl)](2) (9) were obtained along with crystallines of 8cm during the crystallization process. The crystal structures of all three compounds, 4cmmO, 8cmm and 9 were determined by single-crystal X-ray diffraction methods. Fair to excellent efficiencies were observed for employing 4cmm/palladium salt as catalytic precursor in amination as well as in Suzuki coupling reactions.

• 出版日期2009-1-1