Skip to main content

Research Repository

Advanced Search

Visible light mediated oxidation of benzylic sp3 C–H bonds using catalytic 1,4hydroquinone, or its biorenewable glucoside, arbutin, as a pre-oxidant

Finney, Laura C.; Mitchell, Lorna, J.; Moody, Christopher J.

Authors

Laura C. Finney

Lorna, J. Mitchell pcxljmi@nottingham.ac.uk

Christopher J. Moody



Abstract

Benzylic ethers undergo a visible light induced C–H activation and oxygen insertion to give the corresponding benzoate esters in moderate to good yields. The conditions employ substoichiometric amounts of 1,4-hydroquinone with copper(II) chloride dihydrate as an electron-transfer mediator, oxygen as the terminal oxidant and dimethyl carbonate as solvent under visible light irradiation. The naturally occurring glucoside, arbutin, which is commercially available or can be accessed via extraction of the leaves of bearberry (Arctostaphylos uva-ursi) or elephant ears (Bergenia crassifolia) can be used as a biorenewable source of 1,4-hydroquinone. The methodology exploits the increase in oxidizing ability of quinones upon irradiation with visible light, and offers a sustainable alternative for the late stage oxidative functionalization of benzylic C–H bonds. It is applicable to a range of cyclic benzylic ethers such as isochromans and phthalans, and simple benzyl alkyl ethers. It can also be applied in the oxidation of benzylic amines into amides, and of diarylmethanes into the corresponding ketones. Mechanistic studies suggest that the reaction proceeds by Habstraction by the photo-excited triplet benzoquinone to give a benzylic radical that subsequently reacts with molecular oxygen.

Citation

Finney, L. C., Mitchell, L. J., & Moody, C. J. (2018). Visible light mediated oxidation of benzylic sp3 C–H bonds using catalytic 1,4hydroquinone, or its biorenewable glucoside, arbutin, as a pre-oxidant. Green Chemistry, 20(10), https://doi.org/10.1039/C7GC03741D

Journal Article Type Article
Acceptance Date Apr 12, 2018
Online Publication Date Apr 17, 2018
Publication Date May 21, 2018
Deposit Date May 9, 2018
Publicly Available Date Apr 18, 2019
Journal Green Chemistry
Print ISSN 1463-9262
Electronic ISSN 1463-9270
Publisher Royal Society of Chemistry
Peer Reviewed Peer Reviewed
Volume 20
Issue 10
DOI https://doi.org/10.1039/C7GC03741D
Public URL http://eprints.nottingham.ac.uk/id/eprint/51625
Publisher URL http://pubs.rsc.org/en/content/articlelanding/2018/gc/c7gc03741d#!divAbstract
Copyright Statement Copyright information regarding this work can be found at the following address: http://eprints.nottingham.ac.uk/end_user_agreement.pdf

Files


Chris Moody Visible light mediated oxidation.pdf (636 Kb)
PDF

Copyright Statement
Copyright information regarding this work can be found at the following address: http://eprints.nottingham.ac.uk/end_user_agreement.pdf





You might also like



Downloadable Citations