Bicyclic phosphines as ligands for cobalt-catalysed hydroformylation

Autor:	Werner Janse van Rensburg, Chantelle Crause, Llewellyn Damoense, Cronje Grove, Linette Bennie, Konrad Mokheseng, Petrus J. Steynberg, Catherine L. Dwyer, Megan M. Kirk, Stefanus Otto, Neil Grimmer
Rok vydání:	2003
Předmět:	chemistry.chemical_classification Bicyclic molecule Alkene Substituent chemistry.chemical_element Medicinal chemistry Catalysis Inorganic Chemistry chemistry.chemical_compound chemistry Organic chemistry Selectivity Cobalt Hydroformylation Phosphine
Zdroj:	Dalton Trans.. :2036-2042
ISSN:	1477-9234 1477-9226
DOI:	10.1039/b210650g
Popis:	A range of tertiary phosphine ligands derived from (R)-(+)-limonene was studied by HP-31P NMR, HP-IR, batch autoclave reactions and molecular modelling during the hydroformylation of 1-dodecene using a cobalt catalyst system and a metal ∶ ligand ratio of 1 ∶ 2. The phosphorus atom was incorporated in a limonene bicycle where the third substituent was systematically varied, Lim-R (R = (CH2)17CH3, (CH2)9CH3, (CH2)4CH3, (CH2)3CH3, (CH2)3C6H5, (CH2)3CN, (CH2)3OCH2C6H5, (CH2)2OCH2CH3). The activity and selectivity was, to a large extent, governed by the equilibria between the modified and unmodified cobalt catalytic species in the reaction. Linearity ranged from 54 to 71% with Lim-(CH2)3CN yielding the most branched product and Lim-(CH2)4CH3 the most linear product. The n ∶ iso ratio (ratio of linear to 2-methyl branched alcohol) also followed the same trend with a ratio of 2.6 for Lim-(CH2)3CN and 4.9 for Lim-(CH2)4CH3. The rate decreased as the linearity increased with pseudo k values of 0.5 to 1.1. Hydrogenation of the alkene varied within a narrow band from 5–6%.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::448f2f629b68732e5af1476d7d14888e https://doi.org/10.1039/b210650g Zobrazit plný text záznamu