CC BY 4.0 · Sustainability & Circularity NOW 2025; 02: a25056356
DOI: 10.1055/a-2505-6356
Sustainable Solvents
Original Article

Aqueous Mixtures of Deep Eutectic Solvents: Tuning the Reaction Medium and Photocatalyst for Highly Selective Amine Oxidation

Varsha S. Kare
1   Department of Chemistry, Institute of Chemical Technology, Nathalal Parekh Marg, Matunga, Mumbai 400019, India
,
1   Department of Chemistry, Institute of Chemical Technology, Nathalal Parekh Marg, Matunga, Mumbai 400019, India
› Institutsangaben

Funding information Mahatma Jyotiba Phule Research & Training Institute (MAHAJYOTI)—Mahatma Jyotiba Phule Research Fellowship-2022 (MAHAJYOTI/2022/ Ph.D. Fellow/1002).


Abstract

Harvesting light as a source of energy for driving chemical processes is an important aspect of tacking the looming energy crisis. The challenge lies in making the process sustainable while retaining the efficiency and selectivity. In this work, deep eutectic solvents and their aqueous mixtures are used to replace acetonitrile as the reaction medium for the photocatalyzed amine oxidation. It is observed that the use of deep eutectic solvents as reaction media leads to >90% conversion but presents issues with efficient workup due to high viscosity. The use of water a cosolvent mitigates the issue. Further modification of the catalyst surface with alizarin enables the use of higher water content (in a 1:1 ratio) and leads to high conversion (>90%) at one-tenth of irradiation intensity. The high yield and selectivity eliminate the need for tedious purification steps to isolate the product. Control experiments indicate cooperative contributions by TiO2, 2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO), and alizarin as mechanistic factors responsible for the enhanced reactivity.

Supplementary Material



Publikationsverlauf

Eingereicht: 24. September 2024

Angenommen nach Revision: 16. Dezember 2024

Accepted Manuscript online:
18. Dezember 2024

Artikel online veröffentlicht:
22. Januar 2025

© 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/).

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Bibliographical Record
Varsha S. Kare, Shraeddha S. Tiwari. Aqueous Mixtures of Deep Eutectic Solvents: Tuning the Reaction Medium and Photocatalyst for Highly Selective Amine Oxidation. Sustainability & Circularity NOW 2025; 02: a25056356.
DOI: 10.1055/a-2505-6356