Cargando…

Visible-light photoredox-catalyzed C–O bond cleavage of diaryl ethers by acridinium photocatalysts at room temperature

Cleavage of C–O bonds in lignin can afford the renewable aryl sources for fine chemicals. However, the high bond energies of these C–O bonds, especially the 4-O-5-type diaryl ether C–O bonds (~314 kJ/mol) make the cleavage very challenging. Here, we report visible-light photoredox-catalyzed C–O bond...

Descripción completa

Detalles Bibliográficos
Autores principales: Tan, Fang-Fang, He, Xiao-Ya, Tian, Wan-Fa, Li, Yang
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7705023/
https://www.ncbi.nlm.nih.gov/pubmed/33257656
http://dx.doi.org/10.1038/s41467-020-19944-x
_version_ 1783616876994101248
author Tan, Fang-Fang
He, Xiao-Ya
Tian, Wan-Fa
Li, Yang
author_facet Tan, Fang-Fang
He, Xiao-Ya
Tian, Wan-Fa
Li, Yang
author_sort Tan, Fang-Fang
collection PubMed
description Cleavage of C–O bonds in lignin can afford the renewable aryl sources for fine chemicals. However, the high bond energies of these C–O bonds, especially the 4-O-5-type diaryl ether C–O bonds (~314 kJ/mol) make the cleavage very challenging. Here, we report visible-light photoredox-catalyzed C–O bond cleavage of diaryl ethers by an acidolysis with an aryl carboxylic acid and a following one-pot hydrolysis. Two molecules of phenols are obtained from one molecule of diaryl ether at room temperature. The aryl carboxylic acid used for the acidolysis can be recovered. The key to success of the acidolysis is merging visible-light photoredox catalysis using an acridinium photocatalyst and Lewis acid catalysis using Cu(TMHD)(2). Preliminary mechanistic studies indicate that the catalytic cycle occurs via a rare selective electrophilic attack of the generated aryl carboxylic radical on the electron-rich aryl ring of the diphenyl ether. This transformation is applied to a gram-scale reaction and the model of 4-O-5 lignin linkages.
format Online
Article
Text
id pubmed-7705023
institution National Center for Biotechnology Information
language English
publishDate 2020
publisher Nature Publishing Group UK
record_format MEDLINE/PubMed
spelling pubmed-77050232020-12-03 Visible-light photoredox-catalyzed C–O bond cleavage of diaryl ethers by acridinium photocatalysts at room temperature Tan, Fang-Fang He, Xiao-Ya Tian, Wan-Fa Li, Yang Nat Commun Article Cleavage of C–O bonds in lignin can afford the renewable aryl sources for fine chemicals. However, the high bond energies of these C–O bonds, especially the 4-O-5-type diaryl ether C–O bonds (~314 kJ/mol) make the cleavage very challenging. Here, we report visible-light photoredox-catalyzed C–O bond cleavage of diaryl ethers by an acidolysis with an aryl carboxylic acid and a following one-pot hydrolysis. Two molecules of phenols are obtained from one molecule of diaryl ether at room temperature. The aryl carboxylic acid used for the acidolysis can be recovered. The key to success of the acidolysis is merging visible-light photoredox catalysis using an acridinium photocatalyst and Lewis acid catalysis using Cu(TMHD)(2). Preliminary mechanistic studies indicate that the catalytic cycle occurs via a rare selective electrophilic attack of the generated aryl carboxylic radical on the electron-rich aryl ring of the diphenyl ether. This transformation is applied to a gram-scale reaction and the model of 4-O-5 lignin linkages. Nature Publishing Group UK 2020-11-30 /pmc/articles/PMC7705023/ /pubmed/33257656 http://dx.doi.org/10.1038/s41467-020-19944-x Text en © The Author(s) 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Tan, Fang-Fang
He, Xiao-Ya
Tian, Wan-Fa
Li, Yang
Visible-light photoredox-catalyzed C–O bond cleavage of diaryl ethers by acridinium photocatalysts at room temperature
title Visible-light photoredox-catalyzed C–O bond cleavage of diaryl ethers by acridinium photocatalysts at room temperature
title_full Visible-light photoredox-catalyzed C–O bond cleavage of diaryl ethers by acridinium photocatalysts at room temperature
title_fullStr Visible-light photoredox-catalyzed C–O bond cleavage of diaryl ethers by acridinium photocatalysts at room temperature
title_full_unstemmed Visible-light photoredox-catalyzed C–O bond cleavage of diaryl ethers by acridinium photocatalysts at room temperature
title_short Visible-light photoredox-catalyzed C–O bond cleavage of diaryl ethers by acridinium photocatalysts at room temperature
title_sort visible-light photoredox-catalyzed c–o bond cleavage of diaryl ethers by acridinium photocatalysts at room temperature
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7705023/
https://www.ncbi.nlm.nih.gov/pubmed/33257656
http://dx.doi.org/10.1038/s41467-020-19944-x
work_keys_str_mv AT tanfangfang visiblelightphotoredoxcatalyzedcobondcleavageofdiarylethersbyacridiniumphotocatalystsatroomtemperature
AT hexiaoya visiblelightphotoredoxcatalyzedcobondcleavageofdiarylethersbyacridiniumphotocatalystsatroomtemperature
AT tianwanfa visiblelightphotoredoxcatalyzedcobondcleavageofdiarylethersbyacridiniumphotocatalystsatroomtemperature
AT liyang visiblelightphotoredoxcatalyzedcobondcleavageofdiarylethersbyacridiniumphotocatalystsatroomtemperature