Some mechanistic aspects regarding the Suzuki–Miyaura reaction between selected ortho-substituted phenylboronic acids and 3,4,5-tribromo-2,6-dimethylpyridine
Background: Atropisomers are very interesting stereoisomers having axial chirality resulting from restricted rotation around single bonds and are found in various classes of compounds. ortho-Substituted arylpyridines are an important group of them. A regio- and atropselective Suzuki–Miyaura cross-co...
Main Authors: | , , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
Beilstein-Institut
2018-09-01
|
Series: | Beilstein Journal of Organic Chemistry |
Subjects: | |
Online Access: | https://doi.org/10.3762/bjoc.14.214 |
id |
doaj-402e6e0decdd4c05aeade61bac57d3d3 |
---|---|
record_format |
Article |
spelling |
doaj-402e6e0decdd4c05aeade61bac57d3d32021-02-02T00:16:41ZengBeilstein-InstitutBeilstein Journal of Organic Chemistry1860-53972018-09-011412384239310.3762/bjoc.14.2141860-5397-14-214Some mechanistic aspects regarding the Suzuki–Miyaura reaction between selected ortho-substituted phenylboronic acids and 3,4,5-tribromo-2,6-dimethylpyridinePiotr Pomarański0Piotr Roszkowski1Jan K. Maurin2Armand Budzianowski3Zbigniew Czarnocki4Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, PolandFaculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, PolandNational Medicines Institute, Chełmska 30/34, 00-725 Warsaw, PolandNational Centre for Nuclear Research, 05-400 Otwock-Świerk, PolandFaculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, PolandBackground: Atropisomers are very interesting stereoisomers having axial chirality resulting from restricted rotation around single bonds and are found in various classes of compounds. ortho-Substituted arylpyridines are an important group of them. A regio- and atropselective Suzuki–Miyaura cross-coupling reaction on 3,4,5-tribromo-2,6-dimethylpyridine was studied.Results: Reactions with various amounts of ortho-substituted phenylboronic acids with 3,4,5-tribromo-2,6-dimethylpyridine gave a series of mono- di- and triarylpyridine derivatives which allowed to draw conclusions about the order of substitution. Also, the observed selectivity in the case of ortho-methoxyphenylboronic acid suggested an additional metal O-chelation effect in the transition state, apparently not present in the ortho-chloro analogues. The rotational barrier in selected atropisomers was determined on the basis of HT NMR and thermal epimerisation experiments. The structure of most presented atropisomeric derivatives of 2,6-dimethylpyridine was confirmed by single-crystal X-ray analysis. Racemic chiral, differently substituted atropisomers were also examined by 1H NMR spectroscopy in the presence of a chiral solvating agent.Conclusion: This regio- and atropselectivity may be generally applicable to other arylpyridine systems. A regio- and atropselective Suzuki–Miyaura cross-coupling process has been observed, giving an efficient access to a class of atropisomeric compounds. An opposite selectivity using a differently ortho-substituted phenylbornic acid was observed.https://doi.org/10.3762/bjoc.14.214arylpyridinesatropisomerismcross-couplingpalladiumSuzuki–Miyaura reaction |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Piotr Pomarański Piotr Roszkowski Jan K. Maurin Armand Budzianowski Zbigniew Czarnocki |
spellingShingle |
Piotr Pomarański Piotr Roszkowski Jan K. Maurin Armand Budzianowski Zbigniew Czarnocki Some mechanistic aspects regarding the Suzuki–Miyaura reaction between selected ortho-substituted phenylboronic acids and 3,4,5-tribromo-2,6-dimethylpyridine Beilstein Journal of Organic Chemistry arylpyridines atropisomerism cross-coupling palladium Suzuki–Miyaura reaction |
author_facet |
Piotr Pomarański Piotr Roszkowski Jan K. Maurin Armand Budzianowski Zbigniew Czarnocki |
author_sort |
Piotr Pomarański |
title |
Some mechanistic aspects regarding the Suzuki–Miyaura reaction between selected ortho-substituted phenylboronic acids and 3,4,5-tribromo-2,6-dimethylpyridine |
title_short |
Some mechanistic aspects regarding the Suzuki–Miyaura reaction between selected ortho-substituted phenylboronic acids and 3,4,5-tribromo-2,6-dimethylpyridine |
title_full |
Some mechanistic aspects regarding the Suzuki–Miyaura reaction between selected ortho-substituted phenylboronic acids and 3,4,5-tribromo-2,6-dimethylpyridine |
title_fullStr |
Some mechanistic aspects regarding the Suzuki–Miyaura reaction between selected ortho-substituted phenylboronic acids and 3,4,5-tribromo-2,6-dimethylpyridine |
title_full_unstemmed |
Some mechanistic aspects regarding the Suzuki–Miyaura reaction between selected ortho-substituted phenylboronic acids and 3,4,5-tribromo-2,6-dimethylpyridine |
title_sort |
some mechanistic aspects regarding the suzuki–miyaura reaction between selected ortho-substituted phenylboronic acids and 3,4,5-tribromo-2,6-dimethylpyridine |
publisher |
Beilstein-Institut |
series |
Beilstein Journal of Organic Chemistry |
issn |
1860-5397 |
publishDate |
2018-09-01 |
description |
Background: Atropisomers are very interesting stereoisomers having axial chirality resulting from restricted rotation around single bonds and are found in various classes of compounds. ortho-Substituted arylpyridines are an important group of them. A regio- and atropselective Suzuki–Miyaura cross-coupling reaction on 3,4,5-tribromo-2,6-dimethylpyridine was studied.Results: Reactions with various amounts of ortho-substituted phenylboronic acids with 3,4,5-tribromo-2,6-dimethylpyridine gave a series of mono- di- and triarylpyridine derivatives which allowed to draw conclusions about the order of substitution. Also, the observed selectivity in the case of ortho-methoxyphenylboronic acid suggested an additional metal O-chelation effect in the transition state, apparently not present in the ortho-chloro analogues. The rotational barrier in selected atropisomers was determined on the basis of HT NMR and thermal epimerisation experiments. The structure of most presented atropisomeric derivatives of 2,6-dimethylpyridine was confirmed by single-crystal X-ray analysis. Racemic chiral, differently substituted atropisomers were also examined by 1H NMR spectroscopy in the presence of a chiral solvating agent.Conclusion: This regio- and atropselectivity may be generally applicable to other arylpyridine systems. A regio- and atropselective Suzuki–Miyaura cross-coupling process has been observed, giving an efficient access to a class of atropisomeric compounds. An opposite selectivity using a differently ortho-substituted phenylbornic acid was observed. |
topic |
arylpyridines atropisomerism cross-coupling palladium Suzuki–Miyaura reaction |
url |
https://doi.org/10.3762/bjoc.14.214 |
work_keys_str_mv |
AT piotrpomaranski somemechanisticaspectsregardingthesuzukimiyaurareactionbetweenselectedorthosubstitutedphenylboronicacidsand345tribromo26dimethylpyridine AT piotrroszkowski somemechanisticaspectsregardingthesuzukimiyaurareactionbetweenselectedorthosubstitutedphenylboronicacidsand345tribromo26dimethylpyridine AT jankmaurin somemechanisticaspectsregardingthesuzukimiyaurareactionbetweenselectedorthosubstitutedphenylboronicacidsand345tribromo26dimethylpyridine AT armandbudzianowski somemechanisticaspectsregardingthesuzukimiyaurareactionbetweenselectedorthosubstitutedphenylboronicacidsand345tribromo26dimethylpyridine AT zbigniewczarnocki somemechanisticaspectsregardingthesuzukimiyaurareactionbetweenselectedorthosubstitutedphenylboronicacidsand345tribromo26dimethylpyridine |
_version_ |
1724314134486450176 |