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Two Directing Groups Used for Metal Catalysed Meta‐C−H Functionalisation Only Effect Ortho Electrophilic C−H Borylation

Two templates used in meta‐directed C−H functionalisation under metal catalysis do not direct meta‐C−H borylation under electrophilic borylation conditions. Using BCl(3) only Lewis adduct formation with Lewis basic sites in the template is observed. While combining BBr(3) and the template containing...

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Autores principales: Iqbal, Saqib A., Millet, Clement R. P., Pahl, Jürgen, Yuan, Kang, Ingleson, Michael J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9828458/
https://www.ncbi.nlm.nih.gov/pubmed/36636663
http://dx.doi.org/10.1002/ejoc.202200901
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author Iqbal, Saqib A.
Millet, Clement R. P.
Pahl, Jürgen
Yuan, Kang
Ingleson, Michael J.
author_facet Iqbal, Saqib A.
Millet, Clement R. P.
Pahl, Jürgen
Yuan, Kang
Ingleson, Michael J.
author_sort Iqbal, Saqib A.
collection PubMed
description Two templates used in meta‐directed C−H functionalisation under metal catalysis do not direct meta‐C−H borylation under electrophilic borylation conditions. Using BCl(3) only Lewis adduct formation with Lewis basic sites in the template is observed. While combining BBr(3) and the template containing an amide linker only led to amide directed ortho C−H borylation, with no pyridyl directed meta borylation. The amide directed borylation is selective for the ortho borylation of the aniline derived unit in the template, with no ortho borylation of the phenylacetyl ring – which would also form a six membered boracycle – observed. In the absence of other aromatics amide directed ortho borylation on to phenylacetyl rings can be achieved. The absence of meta‐borylation using two templates indicates a higher barrier to pyridyl directed meta borylation relative to amide directed ortho borylation and suggests that bespoke templates for enabling meta‐directed electrophilic borylation may be required.
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spelling pubmed-98284582023-01-10 Two Directing Groups Used for Metal Catalysed Meta‐C−H Functionalisation Only Effect Ortho Electrophilic C−H Borylation Iqbal, Saqib A. Millet, Clement R. P. Pahl, Jürgen Yuan, Kang Ingleson, Michael J. European J Org Chem Research Articles Two templates used in meta‐directed C−H functionalisation under metal catalysis do not direct meta‐C−H borylation under electrophilic borylation conditions. Using BCl(3) only Lewis adduct formation with Lewis basic sites in the template is observed. While combining BBr(3) and the template containing an amide linker only led to amide directed ortho C−H borylation, with no pyridyl directed meta borylation. The amide directed borylation is selective for the ortho borylation of the aniline derived unit in the template, with no ortho borylation of the phenylacetyl ring – which would also form a six membered boracycle – observed. In the absence of other aromatics amide directed ortho borylation on to phenylacetyl rings can be achieved. The absence of meta‐borylation using two templates indicates a higher barrier to pyridyl directed meta borylation relative to amide directed ortho borylation and suggests that bespoke templates for enabling meta‐directed electrophilic borylation may be required. John Wiley and Sons Inc. 2022-11-25 2022-11-25 /pmc/articles/PMC9828458/ /pubmed/36636663 http://dx.doi.org/10.1002/ejoc.202200901 Text en © 2022 The Authors. European Journal of Organic Chemistry published by Wiley-VCH GmbH https://creativecommons.org/licenses/by/4.0/This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Articles
Iqbal, Saqib A.
Millet, Clement R. P.
Pahl, Jürgen
Yuan, Kang
Ingleson, Michael J.
Two Directing Groups Used for Metal Catalysed Meta‐C−H Functionalisation Only Effect Ortho Electrophilic C−H Borylation
title Two Directing Groups Used for Metal Catalysed Meta‐C−H Functionalisation Only Effect Ortho Electrophilic C−H Borylation
title_full Two Directing Groups Used for Metal Catalysed Meta‐C−H Functionalisation Only Effect Ortho Electrophilic C−H Borylation
title_fullStr Two Directing Groups Used for Metal Catalysed Meta‐C−H Functionalisation Only Effect Ortho Electrophilic C−H Borylation
title_full_unstemmed Two Directing Groups Used for Metal Catalysed Meta‐C−H Functionalisation Only Effect Ortho Electrophilic C−H Borylation
title_short Two Directing Groups Used for Metal Catalysed Meta‐C−H Functionalisation Only Effect Ortho Electrophilic C−H Borylation
title_sort two directing groups used for metal catalysed meta‐c−h functionalisation only effect ortho electrophilic c−h borylation
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9828458/
https://www.ncbi.nlm.nih.gov/pubmed/36636663
http://dx.doi.org/10.1002/ejoc.202200901
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