Cargando…

Synthesis of highly functionalized 2,2'-bipyridines by cyclocondensation of β-ketoenamides – scope and limitations

The scope of a flexible route to unsymmetrically functionalized bipyridines is described. Starting from 1,3-diketones 1a–e, the corresponding β-ketoenamines 2a–e were converted into different β-ketoenamides 3a–g by N-acylation with 2-pyridinecarboxylic acid derivatives. These β-ketoenamides were tre...

Descripción completa

Detalles Bibliográficos
Autores principales: Hommes, Paul, Reissig, Hans-Ulrich
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Beilstein-Institut 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4979911/
https://www.ncbi.nlm.nih.gov/pubmed/27559368
http://dx.doi.org/10.3762/bjoc.12.112
_version_ 1782447403042865152
author Hommes, Paul
Reissig, Hans-Ulrich
author_facet Hommes, Paul
Reissig, Hans-Ulrich
author_sort Hommes, Paul
collection PubMed
description The scope of a flexible route to unsymmetrically functionalized bipyridines is described. Starting from 1,3-diketones 1a–e, the corresponding β-ketoenamines 2a–e were converted into different β-ketoenamides 3a–g by N-acylation with 2-pyridinecarboxylic acid derivatives. These β-ketoenamides were treated with a mixture of TMSOTf and Hünig’s base to promote the cyclocondensation to 4-hydroxypyridine derivatives. Their immediate O-nonaflation employing nonafluorobutanesulfonyl fluoride provided the expected 4-nonafloxy-substituted bipyridine derivatives 5a–g in moderate to good overall yields. The bipyridyl nonaflates are excellent precursors for palladium-catalyzed reactions as demonstrated by representative Suzuki and Sonogashira couplings. Thus, a library of specifically substituted bipyridine derivatives was generated, showing the versatility of the simple 1,3-diketone-based approach to this important class of ligands.
format Online
Article
Text
id pubmed-4979911
institution National Center for Biotechnology Information
language English
publishDate 2016
publisher Beilstein-Institut
record_format MEDLINE/PubMed
spelling pubmed-49799112016-08-24 Synthesis of highly functionalized 2,2'-bipyridines by cyclocondensation of β-ketoenamides – scope and limitations Hommes, Paul Reissig, Hans-Ulrich Beilstein J Org Chem Full Research Paper The scope of a flexible route to unsymmetrically functionalized bipyridines is described. Starting from 1,3-diketones 1a–e, the corresponding β-ketoenamines 2a–e were converted into different β-ketoenamides 3a–g by N-acylation with 2-pyridinecarboxylic acid derivatives. These β-ketoenamides were treated with a mixture of TMSOTf and Hünig’s base to promote the cyclocondensation to 4-hydroxypyridine derivatives. Their immediate O-nonaflation employing nonafluorobutanesulfonyl fluoride provided the expected 4-nonafloxy-substituted bipyridine derivatives 5a–g in moderate to good overall yields. The bipyridyl nonaflates are excellent precursors for palladium-catalyzed reactions as demonstrated by representative Suzuki and Sonogashira couplings. Thus, a library of specifically substituted bipyridine derivatives was generated, showing the versatility of the simple 1,3-diketone-based approach to this important class of ligands. Beilstein-Institut 2016-06-09 /pmc/articles/PMC4979911/ /pubmed/27559368 http://dx.doi.org/10.3762/bjoc.12.112 Text en Copyright © 2016, Hommes and Reissig https://creativecommons.org/licenses/by/2.0https://www.beilstein-journals.org/bjoc/termsThis is an Open Access article under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The license is subject to the Beilstein Journal of Organic Chemistry terms and conditions: (https://www.beilstein-journals.org/bjoc/terms)
spellingShingle Full Research Paper
Hommes, Paul
Reissig, Hans-Ulrich
Synthesis of highly functionalized 2,2'-bipyridines by cyclocondensation of β-ketoenamides – scope and limitations
title Synthesis of highly functionalized 2,2'-bipyridines by cyclocondensation of β-ketoenamides – scope and limitations
title_full Synthesis of highly functionalized 2,2'-bipyridines by cyclocondensation of β-ketoenamides – scope and limitations
title_fullStr Synthesis of highly functionalized 2,2'-bipyridines by cyclocondensation of β-ketoenamides – scope and limitations
title_full_unstemmed Synthesis of highly functionalized 2,2'-bipyridines by cyclocondensation of β-ketoenamides – scope and limitations
title_short Synthesis of highly functionalized 2,2'-bipyridines by cyclocondensation of β-ketoenamides – scope and limitations
title_sort synthesis of highly functionalized 2,2'-bipyridines by cyclocondensation of β-ketoenamides – scope and limitations
topic Full Research Paper
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4979911/
https://www.ncbi.nlm.nih.gov/pubmed/27559368
http://dx.doi.org/10.3762/bjoc.12.112
work_keys_str_mv AT hommespaul synthesisofhighlyfunctionalized22bipyridinesbycyclocondensationofbketoenamidesscopeandlimitations
AT reissighansulrich synthesisofhighlyfunctionalized22bipyridinesbycyclocondensationofbketoenamidesscopeandlimitations