Chiral Cationic [Cp′Mo(CO)2(NCMe)]+ Species – Catalyst Precursors for Olefin Epoxidation with H2O2 and tert-Butyl Hydroperoxide
Autor(a) principal: | |
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Data de Publicação: | 2011 |
Outros Autores: | , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10400.26/21979 |
Resumo: | A novel cyclopentadienyl ligand bearing a chiral oxazoline pendant group (Cpox) has been prepared. Its coordination to molybdenum and tungsten afforded optically pure (R)-CpoxM(η3-C3H5)(CO)2 (M = Mo, W) in which the pendant oxazoline fragment is not coordinated to the metal center. Reaction of (R)-CpoxMo(η3-C3H5)(CO)2 with tetrafluoroboric acid gives the bidentate η5-cyclopentadienyloxazoline complex [CpoxMo(CO)2(NCMe)]BF4 in which the oxazoline is coordinated through the N-atom to the molybdenum center. Their catalytic performance in the epoxidation of cis-cyclooctene, (R)-limonene, and trans-β-methylstyrene with H2O2 and tert-butyl hydroperoxide (TBHP) as oxidants has been studied. (R)-CpoxW(η3-C3H5)(CO)2 displayed high catalytic activity achieving quantitative conversion of cyclooctene epoxide in 2 h with H2O2. [CpoxMo(CO)2(NCMe)]+ has been shown to be an efficient catalyst with TBHP and H2O2, reaching quantitative conversions of the corresponding epoxide in 30 min and 11 h, respectively. ESI-MS studies of the reaction of [CpoxMo(CO)2(NCMe)]+ with H2O2 and TBHP revealed the in situ formation of the corresponding peroxido [CpoxMo(O2)O]+ and dioxido [CpoxMoO2]+ species, respectively. Further oxidation of these complexes resulted in the loss of the cyclopentadienyloxazoline ligand. Based on spin trap experiments, the involvement of both carbon- and oxygen-centred radicals in the olefin epoxidation catalyzed by [CpoxMo(CO)2(NCMe)]+ has been proved. |
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Chiral Cationic [Cp′Mo(CO)2(NCMe)]+ Species – Catalyst Precursors for Olefin Epoxidation with H2O2 and tert-Butyl HydroperoxideA novel cyclopentadienyl ligand bearing a chiral oxazoline pendant group (Cpox) has been prepared. Its coordination to molybdenum and tungsten afforded optically pure (R)-CpoxM(η3-C3H5)(CO)2 (M = Mo, W) in which the pendant oxazoline fragment is not coordinated to the metal center. Reaction of (R)-CpoxMo(η3-C3H5)(CO)2 with tetrafluoroboric acid gives the bidentate η5-cyclopentadienyloxazoline complex [CpoxMo(CO)2(NCMe)]BF4 in which the oxazoline is coordinated through the N-atom to the molybdenum center. Their catalytic performance in the epoxidation of cis-cyclooctene, (R)-limonene, and trans-β-methylstyrene with H2O2 and tert-butyl hydroperoxide (TBHP) as oxidants has been studied. (R)-CpoxW(η3-C3H5)(CO)2 displayed high catalytic activity achieving quantitative conversion of cyclooctene epoxide in 2 h with H2O2. [CpoxMo(CO)2(NCMe)]+ has been shown to be an efficient catalyst with TBHP and H2O2, reaching quantitative conversions of the corresponding epoxide in 30 min and 11 h, respectively. ESI-MS studies of the reaction of [CpoxMo(CO)2(NCMe)]+ with H2O2 and TBHP revealed the in situ formation of the corresponding peroxido [CpoxMo(O2)O]+ and dioxido [CpoxMoO2]+ species, respectively. Further oxidation of these complexes resulted in the loss of the cyclopentadienyloxazoline ligand. Based on spin trap experiments, the involvement of both carbon- and oxygen-centred radicals in the olefin epoxidation catalyzed by [CpoxMo(CO)2(NCMe)]+ has been proved.Repositório ComumReis, PatríciaGamelas ou Carla A. Gamelas, CarlaBrito, JoséSaffon, NathalieGoméz, MontserratRoyo, Beatriz2018-03-13T14:54:15Z20112011-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10400.26/21979engReis, P., Gamelas, C., Brito, J., Saffon, N., Gómez, M. & Royo, B. (2011). Chiral Cationic [Cp′Mo(CO)2(NCMe)]+ Species: Catalyst Precursors for Olefin Epoxidation with H2O2 and tert-Butyl Hydroperoxide. European Journal of Inorganic Chemistry, 2011(5), pp. 666-673. doi: 10.1002/ejic.201001065metadata only accessinfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-11-21T09:53:30Zoai:comum.rcaap.pt:10400.26/21979Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T23:09:22.849557Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Chiral Cationic [Cp′Mo(CO)2(NCMe)]+ Species – Catalyst Precursors for Olefin Epoxidation with H2O2 and tert-Butyl Hydroperoxide |
title |
Chiral Cationic [Cp′Mo(CO)2(NCMe)]+ Species – Catalyst Precursors for Olefin Epoxidation with H2O2 and tert-Butyl Hydroperoxide |
spellingShingle |
Chiral Cationic [Cp′Mo(CO)2(NCMe)]+ Species – Catalyst Precursors for Olefin Epoxidation with H2O2 and tert-Butyl Hydroperoxide Reis, Patrícia |
title_short |
Chiral Cationic [Cp′Mo(CO)2(NCMe)]+ Species – Catalyst Precursors for Olefin Epoxidation with H2O2 and tert-Butyl Hydroperoxide |
title_full |
Chiral Cationic [Cp′Mo(CO)2(NCMe)]+ Species – Catalyst Precursors for Olefin Epoxidation with H2O2 and tert-Butyl Hydroperoxide |
title_fullStr |
Chiral Cationic [Cp′Mo(CO)2(NCMe)]+ Species – Catalyst Precursors for Olefin Epoxidation with H2O2 and tert-Butyl Hydroperoxide |
title_full_unstemmed |
Chiral Cationic [Cp′Mo(CO)2(NCMe)]+ Species – Catalyst Precursors for Olefin Epoxidation with H2O2 and tert-Butyl Hydroperoxide |
title_sort |
Chiral Cationic [Cp′Mo(CO)2(NCMe)]+ Species – Catalyst Precursors for Olefin Epoxidation with H2O2 and tert-Butyl Hydroperoxide |
author |
Reis, Patrícia |
author_facet |
Reis, Patrícia Gamelas ou Carla A. Gamelas, Carla Brito, José Saffon, Nathalie Goméz, Montserrat Royo, Beatriz |
author_role |
author |
author2 |
Gamelas ou Carla A. Gamelas, Carla Brito, José Saffon, Nathalie Goméz, Montserrat Royo, Beatriz |
author2_role |
author author author author author |
dc.contributor.none.fl_str_mv |
Repositório Comum |
dc.contributor.author.fl_str_mv |
Reis, Patrícia Gamelas ou Carla A. Gamelas, Carla Brito, José Saffon, Nathalie Goméz, Montserrat Royo, Beatriz |
description |
A novel cyclopentadienyl ligand bearing a chiral oxazoline pendant group (Cpox) has been prepared. Its coordination to molybdenum and tungsten afforded optically pure (R)-CpoxM(η3-C3H5)(CO)2 (M = Mo, W) in which the pendant oxazoline fragment is not coordinated to the metal center. Reaction of (R)-CpoxMo(η3-C3H5)(CO)2 with tetrafluoroboric acid gives the bidentate η5-cyclopentadienyloxazoline complex [CpoxMo(CO)2(NCMe)]BF4 in which the oxazoline is coordinated through the N-atom to the molybdenum center. Their catalytic performance in the epoxidation of cis-cyclooctene, (R)-limonene, and trans-β-methylstyrene with H2O2 and tert-butyl hydroperoxide (TBHP) as oxidants has been studied. (R)-CpoxW(η3-C3H5)(CO)2 displayed high catalytic activity achieving quantitative conversion of cyclooctene epoxide in 2 h with H2O2. [CpoxMo(CO)2(NCMe)]+ has been shown to be an efficient catalyst with TBHP and H2O2, reaching quantitative conversions of the corresponding epoxide in 30 min and 11 h, respectively. ESI-MS studies of the reaction of [CpoxMo(CO)2(NCMe)]+ with H2O2 and TBHP revealed the in situ formation of the corresponding peroxido [CpoxMo(O2)O]+ and dioxido [CpoxMoO2]+ species, respectively. Further oxidation of these complexes resulted in the loss of the cyclopentadienyloxazoline ligand. Based on spin trap experiments, the involvement of both carbon- and oxygen-centred radicals in the olefin epoxidation catalyzed by [CpoxMo(CO)2(NCMe)]+ has been proved. |
publishDate |
2011 |
dc.date.none.fl_str_mv |
2011 2011-01-01T00:00:00Z 2018-03-13T14:54:15Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10400.26/21979 |
url |
http://hdl.handle.net/10400.26/21979 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Reis, P., Gamelas, C., Brito, J., Saffon, N., Gómez, M. & Royo, B. (2011). Chiral Cationic [Cp′Mo(CO)2(NCMe)]+ Species: Catalyst Precursors for Olefin Epoxidation with H2O2 and tert-Butyl Hydroperoxide. European Journal of Inorganic Chemistry, 2011(5), pp. 666-673. doi: 10.1002/ejic.201001065 |
dc.rights.driver.fl_str_mv |
metadata only access info:eu-repo/semantics/openAccess |
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metadata only access |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.source.none.fl_str_mv |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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