Source:http://linkedlifedata.com/resource/pubmed/id/15782267
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| Predicate | Object |
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| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
7
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| pubmed:dateCreated |
2005-3-22
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| pubmed:abstractText |
The fluoroaryl phosphines P{C6H3(CF3)2-3,5}3 (La) and P(C6F5)3 (Lb) form the complexes trans-[MCl2(La)2] and trans-[MCl2(Lb)2](M = Pd or Pt) which have been isolated and fully characterised. 31P NMR studies of competition experiments show that the stability of trans-[PdCl2L2] is in the order L = Lb< La <PPh3. The crystal structure of trans-[PtCl2(La)2] is reported and reveals that the Pt-P bond lengths in trans-[PtCl2L2] are in the order L = Lb< La < PPh3. The equilibria established when [Pt(norbornene)3] is treated with or are investigated by 31P and 195Pt NMR spectroscopy and the species [PtLn(norbornene)3-n](n= 1-3) identified. Ligands and appear to have similar affinities for platinum(0). The complexes trans-[MCl(CO)(La)2] and trans-[MCl(CO)(Lb)2](M = Rh or Ir) have been synthesised and fully characterised; the values of nu(CO) are comparable with those for analogous phosphite complexes. The ligands La, Lb, P(C6H2F3-3,4,5)3 (Lc), P{C6H4(CF3)-2}3 (Ld), PPh3 and P(OPh)3 have been tested in rhodium-catalysed hydroformylation of 1-hexene and La, Lb, and PPh3 have been tested in rhodium-catalysed hydroformylation of 4-methoxystyrene. Ligands La, and Lb, have been shown to be stable under the hydroformylation catalysis conditions. For the 1-hexene reaction, the activity and selectivity for and are very similar to the PPh3 catalyst (TOF ca. 400 h(-1); n : iso 2.5-3.0) but for the sterically demanding and the activity and selectivity was much lower than with PPh3 (TOF ca. 15, n : iso ratio 0.6). Thus, the yield of heptanals obtained with the catalyst derived from La is 94% while under the same conditions with Lb only 6%. The TOF for the La/Rh catalyst was 5 times lower than for the P(OPh)3/Rh catalyst despite the superficially similar ligand electronic characteristics for La and P(OPh)3.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:status |
PubMed-not-MEDLINE
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| pubmed:month |
Apr
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| pubmed:issn |
1477-9226
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:day |
7
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
1294-300
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| pubmed:year |
2005
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| pubmed:articleTitle |
The electron-poor phosphines P{C6H3(CF3)2-3,5}3 and P(C6F5)3 do not mimic phosphites as ligands for hydroformylation. A comparison of the coordination chemistry of P{C6H3(CF3)2-3,5}3 and P(C6F5)3 and the unexpectedly low hydroformylation activity of their rhodium complexes.
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| pubmed:affiliation |
School of Chemistry, University of Bristol, Cantocks Close, Bristol, UK BS8 1TS.
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| pubmed:publicationType |
Journal Article
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