Alternative Non-Ionic Pathway for Uncatalyzed Prins Cyclization: DFT Approach
Autor(a) principal: | |
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Data de Publicação: | 2019 |
Outros Autores: | , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Journal of the Brazilian Chemical Society (Online) |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532019000801717 |
Resumo: | Density functional theory calculations (ωB97X-D/6-311++G(d,p)) are employed to investigate an alternative pathway for Prins-like cyclization. Although strong acids usually catalyze this reaction, 4-amino-1,3-dioxanes are rapidly obtained in high yields without catalyst when benzenamines and acetaldehyde react at low temperatures, in aqueous medium. Considering these conditions, we applied a supermolecule model with explicit water molecules to compute the mechanism for 4-amino-1,3-dioxanes formation from the reactants. The structure of the primary solvation shell was determined by Metropolis Monte Carlo method. In the Prins-cyclization step, we found an unpredicted pathway with non-ionic transition structures or intermediates. Explicit water molecules establish a net of hydrogen bonds allowing prototropism, maintaining the electrical neutrality in the system while two protons transfer occurs. To provide data to further experimental confirmation of this hypothesis, we estimated the kinetic isotope effect for the reaction. We also investigated the use of aliphatic amines, which indicates that the reaction may be of a broader application than first observed experimentally. |
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Alternative Non-Ionic Pathway for Uncatalyzed Prins Cyclization: DFT Approachreaction mechanismsupermolecule modelPrins cyclizationdioxanesDFTDensity functional theory calculations (ωB97X-D/6-311++G(d,p)) are employed to investigate an alternative pathway for Prins-like cyclization. Although strong acids usually catalyze this reaction, 4-amino-1,3-dioxanes are rapidly obtained in high yields without catalyst when benzenamines and acetaldehyde react at low temperatures, in aqueous medium. Considering these conditions, we applied a supermolecule model with explicit water molecules to compute the mechanism for 4-amino-1,3-dioxanes formation from the reactants. The structure of the primary solvation shell was determined by Metropolis Monte Carlo method. In the Prins-cyclization step, we found an unpredicted pathway with non-ionic transition structures or intermediates. Explicit water molecules establish a net of hydrogen bonds allowing prototropism, maintaining the electrical neutrality in the system while two protons transfer occurs. To provide data to further experimental confirmation of this hypothesis, we estimated the kinetic isotope effect for the reaction. We also investigated the use of aliphatic amines, which indicates that the reaction may be of a broader application than first observed experimentally.Sociedade Brasileira de Química2019-08-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532019000801717Journal of the Brazilian Chemical Society v.30 n.8 2019reponame:Journal of the Brazilian Chemical Society (Online)instname:Sociedade Brasileira de Química (SBQ)instacron:SBQ10.21577/0103-5053.20190075info:eu-repo/semantics/openAccessFiorot,Rodolfo G.Rambabu,GottimukkalaVijayakumar,VijayaparthasarathiKiran,Yarragudi B.Carneiro,José W. M.eng2019-08-08T00:00:00Zoai:scielo:S0103-50532019000801717Revistahttp://jbcs.sbq.org.brONGhttps://old.scielo.br/oai/scielo-oai.php||office@jbcs.sbq.org.br1678-47900103-5053opendoar:2019-08-08T00:00Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ)false |
dc.title.none.fl_str_mv |
Alternative Non-Ionic Pathway for Uncatalyzed Prins Cyclization: DFT Approach |
title |
Alternative Non-Ionic Pathway for Uncatalyzed Prins Cyclization: DFT Approach |
spellingShingle |
Alternative Non-Ionic Pathway for Uncatalyzed Prins Cyclization: DFT Approach Fiorot,Rodolfo G. reaction mechanism supermolecule model Prins cyclization dioxanes DFT |
title_short |
Alternative Non-Ionic Pathway for Uncatalyzed Prins Cyclization: DFT Approach |
title_full |
Alternative Non-Ionic Pathway for Uncatalyzed Prins Cyclization: DFT Approach |
title_fullStr |
Alternative Non-Ionic Pathway for Uncatalyzed Prins Cyclization: DFT Approach |
title_full_unstemmed |
Alternative Non-Ionic Pathway for Uncatalyzed Prins Cyclization: DFT Approach |
title_sort |
Alternative Non-Ionic Pathway for Uncatalyzed Prins Cyclization: DFT Approach |
author |
Fiorot,Rodolfo G. |
author_facet |
Fiorot,Rodolfo G. Rambabu,Gottimukkala Vijayakumar,Vijayaparthasarathi Kiran,Yarragudi B. Carneiro,José W. M. |
author_role |
author |
author2 |
Rambabu,Gottimukkala Vijayakumar,Vijayaparthasarathi Kiran,Yarragudi B. Carneiro,José W. M. |
author2_role |
author author author author |
dc.contributor.author.fl_str_mv |
Fiorot,Rodolfo G. Rambabu,Gottimukkala Vijayakumar,Vijayaparthasarathi Kiran,Yarragudi B. Carneiro,José W. M. |
dc.subject.por.fl_str_mv |
reaction mechanism supermolecule model Prins cyclization dioxanes DFT |
topic |
reaction mechanism supermolecule model Prins cyclization dioxanes DFT |
description |
Density functional theory calculations (ωB97X-D/6-311++G(d,p)) are employed to investigate an alternative pathway for Prins-like cyclization. Although strong acids usually catalyze this reaction, 4-amino-1,3-dioxanes are rapidly obtained in high yields without catalyst when benzenamines and acetaldehyde react at low temperatures, in aqueous medium. Considering these conditions, we applied a supermolecule model with explicit water molecules to compute the mechanism for 4-amino-1,3-dioxanes formation from the reactants. The structure of the primary solvation shell was determined by Metropolis Monte Carlo method. In the Prins-cyclization step, we found an unpredicted pathway with non-ionic transition structures or intermediates. Explicit water molecules establish a net of hydrogen bonds allowing prototropism, maintaining the electrical neutrality in the system while two protons transfer occurs. To provide data to further experimental confirmation of this hypothesis, we estimated the kinetic isotope effect for the reaction. We also investigated the use of aliphatic amines, which indicates that the reaction may be of a broader application than first observed experimentally. |
publishDate |
2019 |
dc.date.none.fl_str_mv |
2019-08-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532019000801717 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532019000801717 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.21577/0103-5053.20190075 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
dc.source.none.fl_str_mv |
Journal of the Brazilian Chemical Society v.30 n.8 2019 reponame:Journal of the Brazilian Chemical Society (Online) instname:Sociedade Brasileira de Química (SBQ) instacron:SBQ |
instname_str |
Sociedade Brasileira de Química (SBQ) |
instacron_str |
SBQ |
institution |
SBQ |
reponame_str |
Journal of the Brazilian Chemical Society (Online) |
collection |
Journal of the Brazilian Chemical Society (Online) |
repository.name.fl_str_mv |
Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ) |
repository.mail.fl_str_mv |
||office@jbcs.sbq.org.br |
_version_ |
1750318182099320832 |