Source:http://linkedlifedata.com/resource/pubmed/id/17371024
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
14
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| pubmed:dateCreated |
2007-4-4
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| pubmed:abstractText |
The reaction of a palladiumII-hydride species with molecular oxygen to form palladiumII-hydroperoxide has been proposed as a key step in Pd-catalyzed aerobic oxidation reactions. We recently reported one of the first experimental precedents for such a step (Angew. Chem., Int. Ed. 2006, 45, 2904-2907). DFT calculations have been used to probe the mechanism for this reaction, which consists of formal insertion of O2 into the palladium-hydride bond of trans-(NHC)2Pd(H)OAc (NHC = N-heterocyclic carbene). Four different pathways were considered: (1) hydrogen atom abstraction (HAA) of the Pd-H bond by molecular oxygen, (2) reductive elimination of HX followed by oxygenation of Pd0 and protonolysis of the (eta2-peroxo)-PdII species, (3) oxygenation of palladiumII-hydride with subsequent reductive elimination of the O-H bond from an eta2-peroxo-PdIV center, and (4) formation of a cis-superoxide adduct of the palladium-hydride species followed by O-H bond formation via hydrogen atom migration. The calculations reveal that pathways 1 and 2 are preferred energetically, and both pathways exhibit very similar kinetic barriers. This result suggests that more than one pathway is possible for catalyst reoxidation in Pd-catalyzed aerobic oxidation reactions.
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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 |
0002-7863
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:day |
11
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| pubmed:volume |
129
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
4410-22
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| pubmed:year |
2007
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| pubmed:articleTitle |
Insertion of molecular oxygen into a palladium-hydride bond: computational evidence for two nearly isoenergetic pathways.
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| pubmed:affiliation |
Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, USA. bpopp@chem.wisc.edu
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| pubmed:publicationType |
Journal Article
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