کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1327807 | 977506 | 2009 | 9 صفحه PDF | دانلود رایگان |
Two cobalt-containing bulky monodentate phosphines {[(μ-PPh2CH2PPh2)Co2(CO)4][(μ,η-(tBu)2PCCAr]} (4cm: Ar = 3-CF3C6H4; 4cmm: Ar = 3,5-(CF3)2C6H3) were prepared from the reaction of Co2(CO)6(μ-PPh2CH2PPh2) (3) with each corresponding alkynes (tBu)2PCCAr. Both compounds were converted to their oxidized forms {[(μ-PPh2CH2PPh2)Co2(CO)4][(μ,η-(tBu)2P(O)CCAr]} (4cmO: Ar = 3-CF3C6H3; 4cmmO: Ar = 3,5-(CF3)2C6H3) in the presence of oxide. Further reactions of 4cm and 4cmm with Pd(OAc)2 gave palladium complexes {[(μ-PPh2CH2PPh2)Co2(CO)4][(μ,η-(tBu)2PCC(Ar)-κC1)]Pd(μ-OAc)} 5cm (Ar = 3-CF3C6H3) and 5cmm (Ar = 3,5-(CF3)2C6H2), respectively. By contrast, reactions of 4cm and 4cmm with Pd(COD)Cl2 gave products, [{μ-P,P-PPh2CH2PPh2}Co2(CO)3(μ-CO){μ,η-(tBu)2PCCAr}]-PdCl2] 8cm and 8cmm, respectively, with unique bonding modes. Several crystallines of [(4cm)2Pd3(μ-Cl)(μ-CO)2)(μ-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.
A cobalt-containing bulky monodentate phosphine 4cmm was prepared from the reaction of 3 with corresponding alkyne 2cmm. Its capacity as phosphine ligand in the amination as well as Suzuki coupling reactions in the presence of palladium salt was evaluated.Figure optionsDownload as PowerPoint slide
Journal: Journal of Organometallic Chemistry - Volume 694, Issue 1, 1 January 2009, Pages 113–121