Source:http://linkedlifedata.com/resource/pubmed/id/12398494
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
22
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| pubmed:dateCreated |
2002-10-25
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| pubmed:abstractText |
A silica gel-immobilized [(Me(3)tacn)Ru(III)(CF(3)COO)(2)(H(2)O)]CF(3)CO(2) complex (1-SiO(2), Me(3)tacn = 1,4,7-trimethyl-1,4,7-triazacyclononane) was prepared by simple impregnation, and the catalyst was characterized by powdered X-ray diffraction, nitrogen adsorption/desorption, Raman, and diffuse reflectance UV-vis spectroscopies. The supported Ru catalyst can effect facile oxidation of alcohols by tert-butyl hydroperoxide (TBHP). Primary and secondary benzyl, allylic, and propargylic alcohols were transformed to their corresponding aldehydes and ketones in excellent yields; no oxidation of the C=C and Ctbd1;C bonds was observed for the allylic and propargylic alcohol oxidations. Likewise alkene epoxidation by TBHP can be achieved by 1-SiO(2); cycloalkenes such as norbornene and cyclooctene were oxidized to their exo-epoxides exclusively in excellent yields (>95%). The 1-SiO(2) catalyst can be recycled and reused for consecutive alcohol and alkene oxidations without significant loss of catalytic activity and selectivity; over 9000 turnovers have been attained for the oxidation of 1-phenyl-1-propanol to 1-phenyl-1-propanone. 4-Substituted phenols were oxidized by the "1 + TBHP" protocol to give exclusively ruthenium-catecholate complexes, which were characterized by UV-vis and ESI-MS spectroscopies. No (tert-butyldioxy)cyclohexadienone and other radical coupling/overoxidation products were produced using the "1 + TBHP" protocol. The formation of ruthenium-catecholate is proposed to proceed via ortho-hydroxylation of phenol.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:status |
PubMed-not-MEDLINE
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| pubmed:month |
Nov
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| pubmed:issn |
0022-3263
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:day |
1
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| pubmed:volume |
67
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
7716-23
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| pubmed:year |
2002
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| pubmed:articleTitle |
A silica gel-supported ruthenium complex of 1,4,7-trimethyl-1,4,7-triazacyclononane as recyclable catalyst for chemoselective oxidation of alcohols and alkenes by tert-butyl hydroperoxide.
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| pubmed:affiliation |
Department of Chemistry and Open Laboratory of Chemical Biology of the Institute of Molecular Technology for Drug Discovery and Synthesis, The University of Hong Kong, Pokfulam Road, Hong Kong.
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| pubmed:publicationType |
Journal Article
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