Transformation of PMMA from sunlight‐blocking to sunlight‐activated coupled with DNH photocatalytic platform for oxidative coupling of amines and generation/regeneration of LDC / NADH

• Published in: Photochemistry and photobiology Vol. 100; no. 5; pp. 1247 - 1261
• Main Authors: Singh, Satyam, Yadav, Rajesh K., Umar, Ahmad, Ibrahim, Ahmed A., Kim, Tae Wu, Singh, Atul Pratap, Kumar, Rajesh, Chaudhary, Sandeep, Dwivedi, Dilip K., Singh, Ravindra Vikram, Gupta, Navneet Kumar, Singh, Chandani, Baeg, Jin‐O., Baskoutas, Sotirios
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01.09.2024
• Subjects: Agrochemicals; Amines; Chemical synthesis; Dehydrogenation; Fine chemicals; Harvesting; Hydrazine; Hydrazines; Imines; Intermediates; NADH; Nicotinamide adenine dinucleotide; Nitriles; Oxidation; Photocatalysis; Photocatalysts; Photooxidation; Polymers; Polymethyl methacrylate; Polymethylmethacrylate; Regeneration; Sunlight; oxidative amine coupling; DNH‐incorporated PMMA photocatalyst; photocatalysis; leucodopaminechrome; NADH regeneration
• ISSN: 0031-8655; 1751-1097; 1751-1097
• DOI: 10.1111/php.13888

The photocatalytic oxidation and generation/regeneration of amines to imines and leucodopaminechrome (LDC)/NADH are subjects of intense interest in contemporary research. Imines serve as crucial intermediates for the synthesis of solar fuels, fine chemicals, agricultural chemicals, and pharmaceuticals. While significant progress has been made in developing efficient processes for the oxidation and generation/regeneration of secondary amines, the oxidation of primary amines has received comparatively less attention until recently. This discrepancy can be attributed to the high reactivity of imines generated from primary amines, which are prone to dehydrogenation into nitriles. In this study, we present the synthesis and characterization of a novel polymer‐based photocatalyst, denoted as PMMA‐DNH, designed for solar light‐harvesting applications. PMMA‐DNH incorporates the light‐harvesting molecule dinitrophenyl hydrazine (DNH) at varying concentrations (5%, 10%, 20%, 30%, and 40%). Leveraging its high molar extinction coefficient and slow charge recombination, the 30% DNH‐incorporated PMMA photocatalyst proves to be particularly efficient. This photocatalytic system demonstrates exceptional yields (96.5%) in imine production and high generation/regeneration rates for LDC/NADH (65.27%/78.77%). The research presented herein emphasizes the development and application of a newly engineered polymer‐based photocatalyst, which holds significant promise for direct solar‐assisted chemical synthesis in diverse commercial applications.