Structural and Catalytic Properties of Alkyl-Substituted Phosphanes. Effect of Ortho-Modification on Rhodium-Catalyzed 1-Hexene Hydroformylation

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• 作者：Pekka Suomalainen ; Helena Riihim?ki ; Sirpa J??skel?inen ; Matti Haukka ; Jouni T. Pursiainen and Tapani A. Pakkanen
• 关键词：rhodium ; phosphane ligands ; 1 ; hexene hydroformylation
• 刊名：Catalysis Letters
• 出版年：2001
• 出版时间：2001
• 年：2001
• 卷：77
• 期：1/3
• 页码：125-130
• 全文大小：121 KB

文摘

The influence of the alkyl-substituted phosphanes (o-methylphenyl)diphenylphosphane (o-MeP), (o-ethylphenyl)diphenylphosphane (o-EtP), bis(o-methylphenyl)phenylphosphane (o-Me₂P), bis(o-ethylphenyl)phenylphosphane (o-Et₂P), and (2,4,5-trimethylphenyl)diphenylphosphane (2,4,5-MeP) was screened in model reaction of rhodium-catalyzed 1-hexene hydroformylation. Compared with PPh₃, the prepared phosphanes afforded lower chemoselectivity towards aldehydes, but increased the normal to branched ratio. Catalyst results are discussed in relation to stereoelectronic properties of the phosphane ligands. Electron donor capacity of the ligands was studied in terms of spectroscopic data of the trans-RhCl(CO)P₂ species, formed in reaction between Rh₂(-Cl)₂(CO)₄ and the ligands (P). Furthermore, steric attributes of free and bound phosphanes were investigated by Tolmans cone angle method. Crystal structures for ligands o-EtP, o-Me₂P, o-Et₂P, and complexes trans-Rh(CO)Cl(o-MeP)₂ and trans-Rh(CO)Cl(o-Et₂P) were solved as well.