Chemoselective Sulfide and Sulfoxide Oxidations by CpMo(CO)3Cl/HOOR: a DFT Mechanistic Study. Organometallics
Autor(a) principal: | |
---|---|
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/10400.26/21980 |
Resumo: | The mechanism of sulfide and sulfoxide oxidation with peroxides (ROOH, R = H, Me), catalyzed by Mo(VI) complexes, was investigated by means of DFT/PBE1PBE calculations. Two different catalytic systems were considered: the first is based on the dioxocyclopentadienyl (Cp) complex CpMoO2Cl (Cp = η5-C5H5), also active as a catalyst for olefin epoxidation, and the second based on MoO2Cl2. The most favorable mechanism in the Cp system is initiated by the O−H activation of the HOOR oxidant, which in the presence of CpMoO2Cl leads to formation of CpMoO(OH)(OOR)Cl. Although this is the active species for olefin epoxidation, an alternative pathway with lower energy is available. With the crucial H-bond assistance of another oxidant molecule, the oxoperoxo complex CpMoO(O2)Cl forms, with release of alcohol ROH as byproduct and a calculated energy barrier below 25 kcal mol−1. The mechanisms unveiled for sulfide to sulfoxide oxidation and for sulfoxide to sulfone oxidation are equivalent in their general features and follow outer-sphere mechanisms with S-nucleophilic attack from a free molecule of substrate (sulfide or sulfoxide) to the peroxide which is activated through Mo−O coordination. The MoO2Cl2 catalyst follows a similar course, calculated from MoO2Cl2(H2O)(H2O2). Again, explicit consideration of one molecule of solvent (water) proved essential to facilitate the H-transfer processes involved in the mechanism. The highest energy barrier calculated (ca. 25 kcal mol−1) corresponds to a H shift from the Oα to the Oβ atom of the coordinated H2O2 molecule, activating Oα for the oxidation reaction and preparing water (H2Oβ) as the future leaving group. The outer-sphere mechanism ends with coordination of the oxidation product. |
id |
RCAP_c189f91908f9b17b5cef9e8228c18193 |
---|---|
oai_identifier_str |
oai:comum.rcaap.pt:10400.26/21980 |
network_acronym_str |
RCAP |
network_name_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository_id_str |
7160 |
spelling |
Chemoselective Sulfide and Sulfoxide Oxidations by CpMo(CO)3Cl/HOOR: a DFT Mechanistic Study. OrganometallicsThe mechanism of sulfide and sulfoxide oxidation with peroxides (ROOH, R = H, Me), catalyzed by Mo(VI) complexes, was investigated by means of DFT/PBE1PBE calculations. Two different catalytic systems were considered: the first is based on the dioxocyclopentadienyl (Cp) complex CpMoO2Cl (Cp = η5-C5H5), also active as a catalyst for olefin epoxidation, and the second based on MoO2Cl2. The most favorable mechanism in the Cp system is initiated by the O−H activation of the HOOR oxidant, which in the presence of CpMoO2Cl leads to formation of CpMoO(OH)(OOR)Cl. Although this is the active species for olefin epoxidation, an alternative pathway with lower energy is available. With the crucial H-bond assistance of another oxidant molecule, the oxoperoxo complex CpMoO(O2)Cl forms, with release of alcohol ROH as byproduct and a calculated energy barrier below 25 kcal mol−1. The mechanisms unveiled for sulfide to sulfoxide oxidation and for sulfoxide to sulfone oxidation are equivalent in their general features and follow outer-sphere mechanisms with S-nucleophilic attack from a free molecule of substrate (sulfide or sulfoxide) to the peroxide which is activated through Mo−O coordination. The MoO2Cl2 catalyst follows a similar course, calculated from MoO2Cl2(H2O)(H2O2). Again, explicit consideration of one molecule of solvent (water) proved essential to facilitate the H-transfer processes involved in the mechanism. The highest energy barrier calculated (ca. 25 kcal mol−1) corresponds to a H shift from the Oα to the Oβ atom of the coordinated H2O2 molecule, activating Oα for the oxidation reaction and preparing water (H2Oβ) as the future leaving group. The outer-sphere mechanism ends with coordination of the oxidation product.Repositório ComumVeiros, LuísGamelas ou Carla A. Gamelas, CarlaCalhorda, Maria JoséRomão, Carlos2018-03-13T14:54:27Z20112011-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10400.26/21980engVeiros, L., Gamelas, C., Calhorda, M.J. & Romão, C. (2011). Chemoselective Sulfide and Sulfoxide Oxidations by CpMo(CO)3Cl/HOOR: a DFT Mechanistic Study. Organometallics, 30 (6), pp.1454 -1465. doi: 10.1021/om101044fmetadata 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:10400.26/21980Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T23:09:22.891098Repositório 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 |
Chemoselective Sulfide and Sulfoxide Oxidations by CpMo(CO)3Cl/HOOR: a DFT Mechanistic Study. Organometallics |
title |
Chemoselective Sulfide and Sulfoxide Oxidations by CpMo(CO)3Cl/HOOR: a DFT Mechanistic Study. Organometallics |
spellingShingle |
Chemoselective Sulfide and Sulfoxide Oxidations by CpMo(CO)3Cl/HOOR: a DFT Mechanistic Study. Organometallics Veiros, Luís |
title_short |
Chemoselective Sulfide and Sulfoxide Oxidations by CpMo(CO)3Cl/HOOR: a DFT Mechanistic Study. Organometallics |
title_full |
Chemoselective Sulfide and Sulfoxide Oxidations by CpMo(CO)3Cl/HOOR: a DFT Mechanistic Study. Organometallics |
title_fullStr |
Chemoselective Sulfide and Sulfoxide Oxidations by CpMo(CO)3Cl/HOOR: a DFT Mechanistic Study. Organometallics |
title_full_unstemmed |
Chemoselective Sulfide and Sulfoxide Oxidations by CpMo(CO)3Cl/HOOR: a DFT Mechanistic Study. Organometallics |
title_sort |
Chemoselective Sulfide and Sulfoxide Oxidations by CpMo(CO)3Cl/HOOR: a DFT Mechanistic Study. Organometallics |
author |
Veiros, Luís |
author_facet |
Veiros, Luís Gamelas ou Carla A. Gamelas, Carla Calhorda, Maria José Romão, Carlos |
author_role |
author |
author2 |
Gamelas ou Carla A. Gamelas, Carla Calhorda, Maria José Romão, Carlos |
author2_role |
author author author |
dc.contributor.none.fl_str_mv |
Repositório Comum |
dc.contributor.author.fl_str_mv |
Veiros, Luís Gamelas ou Carla A. Gamelas, Carla Calhorda, Maria José Romão, Carlos |
description |
The mechanism of sulfide and sulfoxide oxidation with peroxides (ROOH, R = H, Me), catalyzed by Mo(VI) complexes, was investigated by means of DFT/PBE1PBE calculations. Two different catalytic systems were considered: the first is based on the dioxocyclopentadienyl (Cp) complex CpMoO2Cl (Cp = η5-C5H5), also active as a catalyst for olefin epoxidation, and the second based on MoO2Cl2. The most favorable mechanism in the Cp system is initiated by the O−H activation of the HOOR oxidant, which in the presence of CpMoO2Cl leads to formation of CpMoO(OH)(OOR)Cl. Although this is the active species for olefin epoxidation, an alternative pathway with lower energy is available. With the crucial H-bond assistance of another oxidant molecule, the oxoperoxo complex CpMoO(O2)Cl forms, with release of alcohol ROH as byproduct and a calculated energy barrier below 25 kcal mol−1. The mechanisms unveiled for sulfide to sulfoxide oxidation and for sulfoxide to sulfone oxidation are equivalent in their general features and follow outer-sphere mechanisms with S-nucleophilic attack from a free molecule of substrate (sulfide or sulfoxide) to the peroxide which is activated through Mo−O coordination. The MoO2Cl2 catalyst follows a similar course, calculated from MoO2Cl2(H2O)(H2O2). Again, explicit consideration of one molecule of solvent (water) proved essential to facilitate the H-transfer processes involved in the mechanism. The highest energy barrier calculated (ca. 25 kcal mol−1) corresponds to a H shift from the Oα to the Oβ atom of the coordinated H2O2 molecule, activating Oα for the oxidation reaction and preparing water (H2Oβ) as the future leaving group. The outer-sphere mechanism ends with coordination of the oxidation product. |
publishDate |
2011 |
dc.date.none.fl_str_mv |
2011 2011-01-01T00:00:00Z 2018-03-13T14:54:27Z |
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/10400.26/21980 |
url |
http://hdl.handle.net/10400.26/21980 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Veiros, L., Gamelas, C., Calhorda, M.J. & Romão, C. (2011). Chemoselective Sulfide and Sulfoxide Oxidations by CpMo(CO)3Cl/HOOR: a DFT Mechanistic Study. Organometallics, 30 (6), pp.1454 -1465. doi: 10.1021/om101044f |
dc.rights.driver.fl_str_mv |
metadata only access info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
metadata only access |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
|
_version_ |
1799135355464581120 |