Influence of alkyne and azide substituents on the choice of the reaction mechanism of the Cu+-catalyzed addition of azides to iodoalkynes
Autor(a) principal: | |
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Data de Publicação: | 2018 |
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/10284/7824 |
Resumo: | The cycloaddition of azides to iodoalkynes is strongly enhanced by some Cu+-complexes. We have studied computationally six reaction pathways for the cycloaddition of 24 combinations of azide and iodoalkyne to identify the dominant pathways and the influence of reactant structure on the evolution of the reaction. Two pathways were found to be operating for distinct sets of reactants. In the first pathway, initial complexation of iodoalkyne by Cu+ is followed by the binding of the azide to the metal through its substituted nitrogen atom, followed by attack of the nonhalogenated alkyne carbon by the terminal nitrogen atom. This pathway is generally followed by aromatic or electron-deficient azides, unless the iodoalkyne bears an electron-withdrawing group. The second pathway is a single-step mechanism similar (apart from the alkyne bond weakening caused by complexation) to that observed in the absence of catalyst. Electron-deficient iodoalkynes and methyl azides strongly prefer this mechanism, regardless of the identity of the reaction partners. The catalytic gain obtained through the use of Cu+ depends only partially on its direct effect on the energy of the transition state (relative to that of the infinitely separated reactants) and may be lost if the iodoalkyne itself strongly interacts with the catalyst through the formation of too strong a π-complex. |
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Influence of alkyne and azide substituents on the choice of the reaction mechanism of the Cu+-catalyzed addition of azides to iodoalkynesThe cycloaddition of azides to iodoalkynes is strongly enhanced by some Cu+-complexes. We have studied computationally six reaction pathways for the cycloaddition of 24 combinations of azide and iodoalkyne to identify the dominant pathways and the influence of reactant structure on the evolution of the reaction. Two pathways were found to be operating for distinct sets of reactants. In the first pathway, initial complexation of iodoalkyne by Cu+ is followed by the binding of the azide to the metal through its substituted nitrogen atom, followed by attack of the nonhalogenated alkyne carbon by the terminal nitrogen atom. This pathway is generally followed by aromatic or electron-deficient azides, unless the iodoalkyne bears an electron-withdrawing group. The second pathway is a single-step mechanism similar (apart from the alkyne bond weakening caused by complexation) to that observed in the absence of catalyst. Electron-deficient iodoalkynes and methyl azides strongly prefer this mechanism, regardless of the identity of the reaction partners. The catalytic gain obtained through the use of Cu+ depends only partially on its direct effect on the energy of the transition state (relative to that of the infinitely separated reactants) and may be lost if the iodoalkyne itself strongly interacts with the catalyst through the formation of too strong a π-complex.Repositório Institucional da Universidade Fernando PessoaSilva, Pedro J.Bernardo, Carlos E. P.2019-09-12T08:46:41Z2018-01-01T00:00:00Z2018-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10284/7824engSilva P.J., Bernardo C.E.P. (2018). Influence of Alkyne and Azide Substituents on the Choice of the Reaction Mechanism of the Cu+-Catalyzed Addition of Azides to Iodoalkynes. The Journal of Physical Chemistry. A,122 (37): 7497-7507. doi: 10.1021/acs.jpca.8b06894. ISSN 1089-5639.1089-563910.1021/acs.jpca.8b068941520-5215info: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:RCAAP2022-09-06T02:07:11Zoai:bdigital.ufp.pt:10284/7824Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T15:44:43.893616Repositório 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 |
Influence of alkyne and azide substituents on the choice of the reaction mechanism of the Cu+-catalyzed addition of azides to iodoalkynes |
title |
Influence of alkyne and azide substituents on the choice of the reaction mechanism of the Cu+-catalyzed addition of azides to iodoalkynes |
spellingShingle |
Influence of alkyne and azide substituents on the choice of the reaction mechanism of the Cu+-catalyzed addition of azides to iodoalkynes Silva, Pedro J. |
title_short |
Influence of alkyne and azide substituents on the choice of the reaction mechanism of the Cu+-catalyzed addition of azides to iodoalkynes |
title_full |
Influence of alkyne and azide substituents on the choice of the reaction mechanism of the Cu+-catalyzed addition of azides to iodoalkynes |
title_fullStr |
Influence of alkyne and azide substituents on the choice of the reaction mechanism of the Cu+-catalyzed addition of azides to iodoalkynes |
title_full_unstemmed |
Influence of alkyne and azide substituents on the choice of the reaction mechanism of the Cu+-catalyzed addition of azides to iodoalkynes |
title_sort |
Influence of alkyne and azide substituents on the choice of the reaction mechanism of the Cu+-catalyzed addition of azides to iodoalkynes |
author |
Silva, Pedro J. |
author_facet |
Silva, Pedro J. Bernardo, Carlos E. P. |
author_role |
author |
author2 |
Bernardo, Carlos E. P. |
author2_role |
author |
dc.contributor.none.fl_str_mv |
Repositório Institucional da Universidade Fernando Pessoa |
dc.contributor.author.fl_str_mv |
Silva, Pedro J. Bernardo, Carlos E. P. |
description |
The cycloaddition of azides to iodoalkynes is strongly enhanced by some Cu+-complexes. We have studied computationally six reaction pathways for the cycloaddition of 24 combinations of azide and iodoalkyne to identify the dominant pathways and the influence of reactant structure on the evolution of the reaction. Two pathways were found to be operating for distinct sets of reactants. In the first pathway, initial complexation of iodoalkyne by Cu+ is followed by the binding of the azide to the metal through its substituted nitrogen atom, followed by attack of the nonhalogenated alkyne carbon by the terminal nitrogen atom. This pathway is generally followed by aromatic or electron-deficient azides, unless the iodoalkyne bears an electron-withdrawing group. The second pathway is a single-step mechanism similar (apart from the alkyne bond weakening caused by complexation) to that observed in the absence of catalyst. Electron-deficient iodoalkynes and methyl azides strongly prefer this mechanism, regardless of the identity of the reaction partners. The catalytic gain obtained through the use of Cu+ depends only partially on its direct effect on the energy of the transition state (relative to that of the infinitely separated reactants) and may be lost if the iodoalkyne itself strongly interacts with the catalyst through the formation of too strong a π-complex. |
publishDate |
2018 |
dc.date.none.fl_str_mv |
2018-01-01T00:00:00Z 2018-01-01T00:00:00Z 2019-09-12T08:46:41Z |
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/10284/7824 |
url |
http://hdl.handle.net/10284/7824 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Silva P.J., Bernardo C.E.P. (2018). Influence of Alkyne and Azide Substituents on the Choice of the Reaction Mechanism of the Cu+-Catalyzed Addition of Azides to Iodoalkynes. The Journal of Physical Chemistry. A,122 (37): 7497-7507. doi: 10.1021/acs.jpca.8b06894. ISSN 1089-5639. 1089-5639 10.1021/acs.jpca.8b06894 1520-5215 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
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openAccess |
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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 |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
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RCAAP |
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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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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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