کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1323836 | 977307 | 2006 | 8 صفحه PDF | دانلود رایگان |
Homogeneous catalysis by palladium complexes with phosphorus(III) ligands of the carbonylation of o-xylylene dihalides in the presence of water to form 3-isochromanone has been studied. Triphenylphosphine was found to provide the most effective catalyst, and by-products and intermediates of systems containing this ligand have been investigated. 2-Indanone is one by-product but is unstable to decomposition under catalytic conditions. Excess PPh3 is necessary to prolong activity of the catalyst but is also transformed to bis-phosphonium compound [o-C6H4(CH2PPh3)2]X2 (X = Cl or Br); this quaternization has been investigated and the structure of the bromide salt determined by X-ray diffraction. An unstable oxidative addition product of Pd(PPh3)4 was detected as a probable intermediate and related to the previously reported but catalytically-inactive complex trans-Pd(o-CH2C6H4CH2Cl)Cl(PMe3)2, which has been structurally characterized by X-ray diffraction in this work.
Studies of the Pd-catalyzed synthesis of 3-isochromanone from o-xylylene-α,α′-dihalides are reported, including crystal structures of PdCl(o-CH2C6H4CH2Cl)(PMe3)2 and [o-C6H4(CH2PPh3)2]Br2.Figure optionsDownload as PowerPoint slide
Journal: Journal of Organometallic Chemistry - Volume 691, Issue 11, 15 May 2006, Pages 2378–2385