Article ID Journal Published Year Pages File Type
1323836 Journal of Organometallic Chemistry 2006 8 Pages PDF
Abstract

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.

Graphical abstractStudies 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 full-size imageDownload as PowerPoint slide

Related Topics
Physical Sciences and Engineering Chemistry Inorganic Chemistry
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