Source:http://linkedlifedata.com/resource/pubmed/id/11456565
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
4
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| pubmed:dateCreated |
2001-7-17
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| pubmed:abstractText |
The regioselectivity of styrene insertion to an acyl-Pd bond was studied by NMR in (i) a stoichiomeric reaction and (ii) a copolymerization with CO. In the stoichiometric reaction of styrene with [(CH(3)CO)Pd(CH(3)CN)[(R,S)-BINAPHOS]].[B[3,5-(CF(3))(2)C(6)H(3)](4)], both 1,2- and 2,1-products were given. To mimic the real polymerization conditions, a polyketone-substituted complex [[CH(3)(CH(2)CHCH(3)CO)(n)]Pd[(R,S)-BINAPHOS]].[B(3,5-(CF(3))(2)C(6)H(3))(4)] (n approximately 14) was prepared. When this polymer-attached Pd species was treated with styrene, the 1,2-insertion product was the only detectable species. Thus, exclusive 1,2-insertion is demonstrated to be responsible for the styrene-CO copolymerization, in sharp contrast to the predominant 2,1-insertion with conventional nitrogen ligands. Chain-end analysis revealed that beta-hydride elimination took place from the 2,1-complex but not from the 1,2-complex. Thus, once 2,1-insertion occurs, rapid beta-hydride elimination proceeds to terminate the polymerization, as is common to the other phosphorus-ligand systems. The resulting Pd-H species re-initiates the copolymerization, as was proven by MALDI-TOF mass analysis of the product copolymers.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:status |
PubMed-not-MEDLINE
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| pubmed:month |
Jan
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| pubmed:issn |
0002-7863
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:day |
31
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| pubmed:volume |
123
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
534-44
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| pubmed:dateRevised |
2003-10-31
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| pubmed:year |
2001
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| pubmed:articleTitle |
Predominant 1,2-insertion of styrene in the Pd-catalyzed alternating copolymerization with carbon monoxide.
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| pubmed:affiliation |
Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501 Japan.
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| pubmed:publicationType |
Journal Article
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