Application of Cobalt-containing P∩N Ligands in PalladiumCatalyzed Amination Reactions

• Main Authors: You-Chen Hsiao, 蕭有成
• Other Authors: Feng-E HONG
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/32734199549794247833

碩士 === 國立中興大學 === 化學系所 === 95 === Alkynylphosphines Me2NCH2C≡CPR2 (2a: R = tBu; 2b: R = Ph) were prepared according to the procedures modified from published methods. Further treatment of a dppm-bridged dicobalt compound [Co2(CO)6(μ-P,P-PPh2CH2PPh2)] 3 with one molar equivalent of 2 in toluene at 110˚C afforded alkyne-bridged dicobalt phosphines [(μ-PPh2CH2PPh2)Co2(CO)4(μ,η-Me2NCH2C≡CPR2)] (4a: R = tBu; 4b: R = Ph). A smaller amount of oxidized counterpart [(μ-PPh2CH2PPh2)Co2(CO)4(μ,η-Me2NCH2C≡CP(=O)(t-Bu)2)] 4aO was obtained during the chromatographic process of 4a. Compound 4b and 4aO were characterized by spectroscopic methods as well as single-crystal X-ray diffraction. Both 4a and 4b are authentic cobalt-containing P∩N bidentate ligands and can be used in ligating palladium sources such as Pd(OAc)2 or PdCl2. Reasonable efficiencies were observed for Amination reactions of arylbromides and morpholine employing 4a- or 4b-chelated palladium complex as the catalytic precursor.