Harnessing Ultrasound-Derived Hydroxyl Radicals for the Selective Oxidation of Aldehyde Functions.

Autor: Fischer AF; School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459, Singapore.; Cambridge Centre for Advanced Research and Education in Singapore (CARES), 1 Create Way, Singapore, 138602, Singapore., Bahry T; CNRS, Université de Poitiers, Institut de Chimie des Milieux et Matériaux de Poitiers, 1 rue Marcel Doré, Bat B1 (ENSI-Poitiers), Poitiers, Cedex 9 86073, France., Xie Z; School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459, Singapore., Qian K; National Engineering Lab for Textile Fiber Materials and Processing Technology, Zhejiang Sci-Tech University, Hangzhou, 310018, China., Li R; National Engineering Lab for Textile Fiber Materials and Processing Technology, Zhejiang Sci-Tech University, Hangzhou, 310018, China., Kwan J; Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, United Kingdom., Jerome F; CNRS, Université de Poitiers, Institut de Chimie des Milieux et Matériaux de Poitiers, 1 rue Marcel Doré, Bat B1 (ENSI-Poitiers), Poitiers, Cedex 9 86073, France., Valange S; CNRS, Université de Poitiers, Institut de Chimie des Milieux et Matériaux de Poitiers, 1 rue Marcel Doré, Bat B1 (ENSI-Poitiers), Poitiers, Cedex 9 86073, France., Liu W; School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459, Singapore.; Cambridge Centre for Advanced Research and Education in Singapore (CARES), 1 Create Way, Singapore, 138602, Singapore., Amaniampong PN; CNRS, Université de Poitiers, Institut de Chimie des Milieux et Matériaux de Poitiers, 1 rue Marcel Doré, Bat B1 (ENSI-Poitiers), Poitiers, Cedex 9 86073, France., Choksi TS; School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459, Singapore.; Cambridge Centre for Advanced Research and Education in Singapore (CARES), 1 Create Way, Singapore, 138602, Singapore.
Jazyk: angličtina
Zdroj: ChemSusChem [ChemSusChem] 2024 Dec 20; Vol. 17 (24), pp. e202400838.
DOI: 10.1002/cssc.202400838
Abstrakt: Ultrasonic irradiation holds potential for the selective oxidation of non-volatile organic substrates in the aqueous phase by harnessing hydroxyl radicals as chemical initiators. Here, a mechanistic description of hydroxyl radical-initiated glyoxal oxidation is constructed by gleaning insights from photolysis and radiation chemistry to explain the yields and kinetic trends for oxidation products. The mechanistic description and kinetic measurements reported herein reveal that increasing the formation rate of hydroxyl radicals by changing the ultrasound frequency increases both the rates of glyoxal consumption and the selectivity towards C 2 acid products over those from C-C cleavage. Glyoxal consumption also occurs more rapidly and with greater selectivity towards C 2 acids under acidic conditions, which favor the protonation of carboxylate intermediates into their less reactive acidic forms. Leveraging such pH and frequency effects is crucial to mitigating product degradation by secondary reactions with hydroxyl radicals and oxidation products (specifically hydrogen peroxide and superoxide). These findings demonstrate the potential of ultrasound as a driver for the selective oxidation of aldehyde functions to carboxylic acids, offering a sustainable route for valorizing biomass-derived platform molecules.
(© 2024 Wiley-VCH GmbH.)
Databáze: MEDLINE
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