Cargando…

Gold-catalyzed [4+3]- and [4+2]-annulations of 3-en-1-ynamides with isoxazoles via novel 6π-electrocyclizations of 3-azahepta trienyl cations

New gold-catalyzed [4+3]-annulations of 3-en-1-ynamides with isoxazoles afford 4H-azepines efficiently; this process involves 6π electrocyclizations of gold-stabilized 3-azaheptatrienyl cations. In the presence of Zn(OTf)(2), the resulting 4H-azepines undergo skeletal rearrangement to furnish substi...

Descripción completa

Detalles Bibliográficos
Autores principales: Giri, Sovan Sundar, Liu, Rai-Shung
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Royal Society of Chemistry 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5915799/
https://www.ncbi.nlm.nih.gov/pubmed/29732082
http://dx.doi.org/10.1039/c8sc00232k
_version_ 1783316926552866816
author Giri, Sovan Sundar
Liu, Rai-Shung
author_facet Giri, Sovan Sundar
Liu, Rai-Shung
author_sort Giri, Sovan Sundar
collection PubMed
description New gold-catalyzed [4+3]-annulations of 3-en-1-ynamides with isoxazoles afford 4H-azepines efficiently; this process involves 6π electrocyclizations of gold-stabilized 3-azaheptatrienyl cations. In the presence of Zn(OTf)(2), the resulting 4H-azepines undergo skeletal rearrangement to furnish substituted pyridine derivatives. We subsequently develop new catalytic [4+2]-annulations between the same 3-en-1-ynamides and isoxazoles to deliver substituted pyridine products using Au(i)/Zn(ii) catalysts. This work reports the first success of the 6π electrocyclizations of heptatrienyl cations that are unprecedented in literature reports.
format Online
Article
Text
id pubmed-5915799
institution National Center for Biotechnology Information
language English
publishDate 2018
publisher Royal Society of Chemistry
record_format MEDLINE/PubMed
spelling pubmed-59157992018-05-04 Gold-catalyzed [4+3]- and [4+2]-annulations of 3-en-1-ynamides with isoxazoles via novel 6π-electrocyclizations of 3-azahepta trienyl cations Giri, Sovan Sundar Liu, Rai-Shung Chem Sci Chemistry New gold-catalyzed [4+3]-annulations of 3-en-1-ynamides with isoxazoles afford 4H-azepines efficiently; this process involves 6π electrocyclizations of gold-stabilized 3-azaheptatrienyl cations. In the presence of Zn(OTf)(2), the resulting 4H-azepines undergo skeletal rearrangement to furnish substituted pyridine derivatives. We subsequently develop new catalytic [4+2]-annulations between the same 3-en-1-ynamides and isoxazoles to deliver substituted pyridine products using Au(i)/Zn(ii) catalysts. This work reports the first success of the 6π electrocyclizations of heptatrienyl cations that are unprecedented in literature reports. Royal Society of Chemistry 2018-02-19 /pmc/articles/PMC5915799/ /pubmed/29732082 http://dx.doi.org/10.1039/c8sc00232k Text en This journal is © The Royal Society of Chemistry 2018 http://creativecommons.org/licenses/by/3.0/ This article is freely available. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence (CC BY 3.0)
spellingShingle Chemistry
Giri, Sovan Sundar
Liu, Rai-Shung
Gold-catalyzed [4+3]- and [4+2]-annulations of 3-en-1-ynamides with isoxazoles via novel 6π-electrocyclizations of 3-azahepta trienyl cations
title Gold-catalyzed [4+3]- and [4+2]-annulations of 3-en-1-ynamides with isoxazoles via novel 6π-electrocyclizations of 3-azahepta trienyl cations
title_full Gold-catalyzed [4+3]- and [4+2]-annulations of 3-en-1-ynamides with isoxazoles via novel 6π-electrocyclizations of 3-azahepta trienyl cations
title_fullStr Gold-catalyzed [4+3]- and [4+2]-annulations of 3-en-1-ynamides with isoxazoles via novel 6π-electrocyclizations of 3-azahepta trienyl cations
title_full_unstemmed Gold-catalyzed [4+3]- and [4+2]-annulations of 3-en-1-ynamides with isoxazoles via novel 6π-electrocyclizations of 3-azahepta trienyl cations
title_short Gold-catalyzed [4+3]- and [4+2]-annulations of 3-en-1-ynamides with isoxazoles via novel 6π-electrocyclizations of 3-azahepta trienyl cations
title_sort gold-catalyzed [4+3]- and [4+2]-annulations of 3-en-1-ynamides with isoxazoles via novel 6π-electrocyclizations of 3-azahepta trienyl cations
topic Chemistry
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5915799/
https://www.ncbi.nlm.nih.gov/pubmed/29732082
http://dx.doi.org/10.1039/c8sc00232k
work_keys_str_mv AT girisovansundar goldcatalyzed43and42annulationsof3en1ynamideswithisoxazolesvianovel6pelectrocyclizationsof3azaheptatrienylcations
AT liuraishung goldcatalyzed43and42annulationsof3en1ynamideswithisoxazolesvianovel6pelectrocyclizationsof3azaheptatrienylcations