A pair of 9-mesityl-10-phenyl acridinium (Mes-Acr ) photoredox catalysts were synthesized with an iodoacetamide handle for cysteine bioconjugation. Covalently tethering of the synthetic Mes-Acr cofactors with a small panel of thermostable protein scaffolds resulted in 12 new artificial enzymes. The unique chemical and structural environment of the protein hosts had a measurable effect on the photophysical properties and photocatalytic activity of the cofactors. The constructed Mes-Acr hybrid enzymes were found to be active photoinduced electron-transfer catalysts, controllably oxidizing a variety of aryl sulfides when irradiated with visible light, and possessed activities that correlated with the photophysical characterization data. Their catalytic performance was found to depend on multiple factors including the Mes-Acr cofactor, the protein scaffold, the location of cofactor immobilization, and the substrate. This work provides a framework toward adapting synthetic photoredox catalysts into artificial cofactors and includes important considerations for future bioengineering efforts.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/cbic.202000362 | DOI Listing |
Org Lett
January 2025
Department of Chemistry, Indian Institute of Technology, Roorkee, Uttarakhand 247667, India.
A photoacid-catalyzed method for esterification is proposed wherein eosin Y is introduced as a photoacid and photoredox catalyst that can be activated with visible light and catalyze the esterification of carboxylic acids. The strategy presented here revealed that proton-coupled electron transfer (PCET) between eosin Y and carboxylic acid might facilitate the formation of a transient ketyl radical. This ketyl radical would subsequently undergo a single electron transfer and then couple with alkyl alcohols, yielding carboxylic esters in good to excellent yields.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, People's Republic of China.
The concurrent evolution of value-added benzimidazole compounds and hydrogen within the domain of chemical synthesis is of paramount importance. The utilization of photocatalysis enhances both the efficiency and environmental benignity of the synthetic process. However, it is profoundly challenging within a photocatalytic system to simultaneously augment the number of active sites and the internal transport rate of photogenerated charge carriers.
View Article and Find Full Text PDFChem Sci
January 2025
Institute for Chemical Research, Kyoto University Gokasho Uji Kyoto 611-0011 Japan
Proton-coupled electron transfer (PCET) is a crucial chemical process involving the simultaneous or sequential transfer of protons and electrons, playing a vital role in biological processes and energy conversion technologies. This study investigates the use of an organic photoredox catalyst to facilitate a unimolecular PCET process for the generation of alkyl radicals from benzylic alcohols, with a particular focus on alcohols containing electron-rich arene units. By employing a benzophenone derivative as the catalyst, the reaction proceeds efficiently under photoirradiation, achieving significant yields without the need for a Brønsted base.
View Article and Find Full Text PDFOrg Lett
January 2025
Gansu International Scientific and Technological Cooperation Base of Water-Retention Chemical Functional Materials, Key Laboratory of Eco-Environment-Related Polymer Materials Ministry of Education, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, Gansu 730070, China.
Here, we present a three-component successive radical addition strategy for the preparation of complex noncanonical α-amino acids from easily available glycine derivatives, alkenes, and aryl sulfonium salts via a copper-catalyzed photoredox-neutral catalytic cycle. The utility of this method is further demonstrated by its application in late-stage site-selective modifications of glycine residues in short peptides. It is worth noting that only 1 mol % copper catalyst is required in this reaction, demonstrating high catalytic efficiency.
View Article and Find Full Text PDFJ Chem Phys
January 2025
Department of Chemistry and Biochemistry, University of Texas at El Paso, El Paso, Texas 79968, USA.
This study investigates the impact of structural isomerism on the excited state lifetime and redox energetics of heteroleptic [Ir(ppy)2(bpy)]+ and homoleptic Ir(ppy)3 photoredox catalysts using ground-state and time-dependent density functional theory methods. While the ground- and excited-state reduction potentials differ only slightly among the isomers of these complexes, our findings reveal significant variations in the radiative and non-radiative decay rates of the reactivity-controlling triplet 3MLCT states of these closely related species. The observed differences in radiative decay rates could be traced back to variations in the transition dipole moment, vertical energy gaps, and spin-orbit coupling of the isomers.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!