File Download

There are no files associated with this item.

  Links for fulltext
     (May Require Subscription)
Supplementary

Article: Ruthenium meso-tetrakis(2,6-dichlorophenyl)porphyrin complex immobilized in mesoporous MCM-41 as a heterogeneous catalyst for selective alkene epoxidations

TitleRuthenium meso-tetrakis(2,6-dichlorophenyl)porphyrin complex immobilized in mesoporous MCM-41 as a heterogeneous catalyst for selective alkene epoxidations
Authors
Issue Date1998
PublisherAmerican Chemical Society. The Journal's web site is located at http://pubs.acs.org/joc
Citation
Journal Of Organic Chemistry, 1998, v. 63 n. 21, p. 7364-7369 How to Cite?
AbstractA ruthenium complex of meso-tetrakis(2,6-dichlorophenyl)porphyrin, [RuII(TDCPP)(CO)(EtOH)], is immobilized into mesoporous MCM-41 molecular sieves; the supported Ru catalyst can effect highly selective heterogeneous alkene epoxidations using 2,6-dichloropyridine TV-oxide as terminal oxidant. Aromatic and aliphatic alkenes can be efficiently converted to their epoxides in good yields and selectivities, and cis-alkenes such as czs-stilbene, cis-β-methylstyrene, and cis-β-deuteriostyrene are epoxidized stereospecifically. Oxidation of cycloalkenes, e.g., norbornene and cyclooctene, can be carried out effectively using the heterogeneous Ru-catalyzed reaction while these alkenes are unreactive in the zeolite-based titanium silicate (TS-l)-catalyzed conditions (Murugavel, R.; Roesky, H. W. Angew. Chem., Int. Ed. Engl. 1997, 36, 477). On the other hand, the Ru/M-41(m) catalyst displays size selectivity in the (+)-limonene oxidation where the terminal C=C bond (vs internal trisubstituted C=C bond) becomes more readily oxidized. Bulky 3,4,6-tri-O-benzyl-D-glucal has failed to react under the heterogeneous Ru-catalyzed conditions, whereas the smaller acetyl derivative is converted to a 3:1 mixture of α- and β-glycal epoxides. The Ru/M-41(m) catalyst can be used repeatedly, and 67% of its initial activity is retained after 11 691 turnovers (three runs). The loss of activity is attributed to catalyst leaching and/or deactivation. On the basis of Hammett correlation (ρ+ = -0.72, R = 0.997) and product studies (cyclohexene and crs-alkenes as the substrates), a reactive dioxorutheniumCVI) porphyrin intermediate is not favored. An oxoruthenium(V) complex or oxoruthenium(IV) porphyrin cation radical could be the key intermediate for this highly selective epoxidation reaction. © 1998 American Chemical Society.
Persistent Identifierhttp://hdl.handle.net/10722/167382
ISSN
2015 Impact Factor: 4.785
2015 SCImago Journal Rankings: 2.095
ISI Accession Number ID
References

 

DC FieldValueLanguage
dc.contributor.authorLiu, CJen_US
dc.contributor.authorYu, WYen_US
dc.contributor.authorLi, SGen_US
dc.contributor.authorChe, CMen_US
dc.date.accessioned2012-10-08T03:06:18Z-
dc.date.available2012-10-08T03:06:18Z-
dc.date.issued1998en_US
dc.identifier.citationJournal Of Organic Chemistry, 1998, v. 63 n. 21, p. 7364-7369en_US
dc.identifier.issn0022-3263en_US
dc.identifier.urihttp://hdl.handle.net/10722/167382-
dc.description.abstractA ruthenium complex of meso-tetrakis(2,6-dichlorophenyl)porphyrin, [RuII(TDCPP)(CO)(EtOH)], is immobilized into mesoporous MCM-41 molecular sieves; the supported Ru catalyst can effect highly selective heterogeneous alkene epoxidations using 2,6-dichloropyridine TV-oxide as terminal oxidant. Aromatic and aliphatic alkenes can be efficiently converted to their epoxides in good yields and selectivities, and cis-alkenes such as czs-stilbene, cis-β-methylstyrene, and cis-β-deuteriostyrene are epoxidized stereospecifically. Oxidation of cycloalkenes, e.g., norbornene and cyclooctene, can be carried out effectively using the heterogeneous Ru-catalyzed reaction while these alkenes are unreactive in the zeolite-based titanium silicate (TS-l)-catalyzed conditions (Murugavel, R.; Roesky, H. W. Angew. Chem., Int. Ed. Engl. 1997, 36, 477). On the other hand, the Ru/M-41(m) catalyst displays size selectivity in the (+)-limonene oxidation where the terminal C=C bond (vs internal trisubstituted C=C bond) becomes more readily oxidized. Bulky 3,4,6-tri-O-benzyl-D-glucal has failed to react under the heterogeneous Ru-catalyzed conditions, whereas the smaller acetyl derivative is converted to a 3:1 mixture of α- and β-glycal epoxides. The Ru/M-41(m) catalyst can be used repeatedly, and 67% of its initial activity is retained after 11 691 turnovers (three runs). The loss of activity is attributed to catalyst leaching and/or deactivation. On the basis of Hammett correlation (ρ+ = -0.72, R = 0.997) and product studies (cyclohexene and crs-alkenes as the substrates), a reactive dioxorutheniumCVI) porphyrin intermediate is not favored. An oxoruthenium(V) complex or oxoruthenium(IV) porphyrin cation radical could be the key intermediate for this highly selective epoxidation reaction. © 1998 American Chemical Society.en_US
dc.languageengen_US
dc.publisherAmerican Chemical Society. The Journal's web site is located at http://pubs.acs.org/jocen_US
dc.relation.ispartofJournal of Organic Chemistryen_US
dc.titleRuthenium meso-tetrakis(2,6-dichlorophenyl)porphyrin complex immobilized in mesoporous MCM-41 as a heterogeneous catalyst for selective alkene epoxidationsen_US
dc.typeArticleen_US
dc.identifier.emailChe, CM:cmche@hku.hken_US
dc.identifier.authorityChe, CM=rp00670en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.doi10.1021/jo981003l-
dc.identifier.pmid11672384-
dc.identifier.scopuseid_2-s2.0-0004558813en_US
dc.identifier.hkuros40274-
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-0004558813&selection=ref&src=s&origin=recordpageen_US
dc.identifier.volume63en_US
dc.identifier.issue21en_US
dc.identifier.spage7364en_US
dc.identifier.epage7369en_US
dc.identifier.isiWOS:000076550200038-
dc.publisher.placeUnited Statesen_US
dc.identifier.scopusauthoridLiu, CJ=7409788746en_US
dc.identifier.scopusauthoridYu, WY=7403913673en_US
dc.identifier.scopusauthoridLi, SG=7409245032en_US
dc.identifier.scopusauthoridChe, CM=7102442791en_US

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats