We disclose herein the first transition-metal- and external oxidant/reductant-free visible-light-mediated synthesis of (un)symmetrical diaryl/alkyl aryl sulfones from arenediazonium tetrafluoroborates and sodium sulfinates using eosin Y as an organic photoredox catalyst. The utilization of visible light as an inexpensive and ecosustainable energy source, operational simplicity, ambient temperature and clean reaction in aqueous acetonitrile are the salient features of the developed protocol. The desired sulfones were also synthesized via a one-pot, two-step process directly from anilines and sulfinate salts in good to excellent yields.
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http://dx.doi.org/10.1039/c9ob00864k | DOI Listing |
Angew Chem Int Ed Engl
January 2025
The University of Arizona, Chemistry and BioChemistry, 1306 E University Blvd, CSML 638, 85719, Tucson, UNITED STATES OF AMERICA.
Diffusion-limited kinetics is a key mechanistic debate when consecutive photoelectron transfer (conPET) is discussed in photoredox catalysis. In-situ generated organic photoactive radicals can access catalytic systems as reducing as alkaline metals that can activate remarkably stable bonds. However, in many cases, the extremely short-lived transient nature of these doublet state open-shell species has led to debatable mechanistic studies, hindering adoption and development.
View Article and Find Full Text PDFChem Asian J
January 2025
Kaili University, School of Life and Health Science, 3 Kaiyuan Road, Kaili Economic Development Zone, 556011, Kaili, CHINA.
Photoredox catalysis has been developed as a sustainable and eco-friendly catalytic strategy, which might provide innovative solutions to solve the current synthetic challenges and barriers in carbohydrate chemistry. During the last few decades, the study of organic photocatalyst-promoted carbohydrate synthesis and modification has received significant attention, which provides an excellent and inexpensive metal-free alternative to photoredox catalysis as well as introduces a new fastest-growing era to access complex carbohydrates simply. In this review, we aim to provide an overview of organic photocatalyst-promoted carbohydrate synthesis and modification under light irradiation, which is expected to provide new directions for further investigation.
View Article and Find Full Text PDFSmall
January 2025
Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
The ligands in metal-organic framework (MOF) play as light absorption center and transfer photogenerated electrons to metal node through ligand-to-metal charge transfer (LMCT) during photocatalysis, and energy utilization efficiency is strongly restricted by the light inertness of ligands. Herein, a ligand updating strategy is proposed by inserting energy centers to MOFs to activate the inherent ligands, realizing boosting hot electron generation and photocatalytic activities via the cascaded proceeding of energy transfer and charge transfer. By taking PCN-777 (a zeotype mesoporous Zr-containing MOF) as an example, this study shows that the embedded energy center of 1-pyrenecarboxylic acid (PCA) can activate the inherent ligand of PCN-777 through triplet-triplet energy transfer, where triplet excitons would dissociate into photocarriers migrating to the Zr metal cluster via LMCT process.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Shanghai Institute of Organic Chemistry, State Key Lab of Organometallic Chemistry, 345 Lingling Road, 200032, Shanghai, CHINA.
A dual photoredox/cobalt-catalyzed protocol for chemo-, regio-, diastereo- and enantioselective reductive coupling of 1,1-disubstituted allenes and cyclobutenes through chemo-, regio-, diastereo- and enantioselective oxidative cyclization followed by stereoselective protonation promoted by a chiral phosphine-cobalt complex is presented. Such process represents an unprecedented reaction pathway for cobalt catalysis that enables selective transformation of the less sterically congested alkenes of 1,1-disubstituted allenes with cyclobutenes, incorporating a broad scope of tetrasubstituted alkenes into the cyclobutane scaffolds in up to 86% yield, >98:2 chemo- and regioselectivity, >98:2 dr and >99.5:0.
View Article and Find Full Text PDFACS Omega
December 2024
Department of Chemistry, Southern Methodist University, Dallas, Texas 75275, United States.
The design and synthesis of photoactive metal-free 2D materials for selective heterogeneous photoredox catalysis continue to be challenging due to issues related to nonrecyclability, and limited photo- and chemical stability. Herein, we report the photocatalytic properties of a triazine-based porous COF, , which is found to be capable of facilitating both SET (single electron transfer) for photocatalytic reductive debromination of phenacyl bromide in absence of oxygen and generation of reactive oxygen species (ROS) for benzylamine photo-oxidation in the presence of oxygen, respectively, under visible light irradiation. Inspired by the latter results, we further systematically investigated different-sized benzylamine substrates in this single-component reaction and compared the results with an analogous COF () exhibiting a larger pore size.
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