Direct alkylation of C(sp )-H bonds to convert an aldehyde into a ketone is a notorious transformation, due to the laborious challenge of the formation of ketyl or acyl radicals. Herein, we report a green, cheap, metal-free and efficient method for the hydroacylation of olefins in water. This photochemical protocol utilizes phenylglyoxylic acid, a commercially available small organic molecule, as the photoinitiator, water as the solvent and household fluorescent lamps as the irradiation source, leading to a broad substrate scope of products in moderate to good yields. A wide range of aromatic and aliphatic aldehydes, terminal and non-terminal alkenes and pharmaceutically relevant molecules can be employed, without the need of directing groups and additives or metal catalysts.
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http://dx.doi.org/10.1002/anie.201912214 | DOI Listing |
ChemSusChem
January 2025
Indian Institute of Technology Ropar, Chemistry, Nangal Road, 140001, Rupnagar, INDIA.
Photocatalytic conversion of CO2 into value-added chemicals offers a propitious alternative to traditional thermal methods, contributing to environmental remediation and energy sustainability. In this respect, covalent organic frameworks (COFs), are crystalline porous materials showcasing remarkable efficacy in CO2 fixation facilitated by visible light owing to their excellent photochemical properties. Herein, we employed Lewis acidic Zn(II) anchored pyrene-based COF (Zn(II)@Pybp-COF) to facilitate the photocatalytic CO2 utilization and transformation to 2-oxazolidinones.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Shanghai Institute of Ceramics Chinese Academy of Sciences, State Key Laboratory of High Performance Ceramics and Superfine Microstructure, CHINA.
Pairing photocatalytic 1,2,3,4-tetrahydroisoquinoline semi-dehydrogenation reaction (THIQ-SDR) with two-electron oxygen reduction reaction (2e- ORR) is a green solar to chemical strategy by simultaneously utilizing the photo-excited electrons and holes. However, it is still short of high-efficiency photocatalyst to drive two reactions above. In the present work, crystalline pyrene-thiourea/urea covalent organic frameworks (COF-Py-S and -O) were synthesized and demonstrated as high-performance metal-free photocatalysts.
View Article and Find Full Text PDFMater Horiz
January 2025
School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study University of Chinese Academy of Sciences, Hangzhou, 310024, P. R. China.
Metal-free photocatalysts derived from earth-abundant elements have drawn significant attention owing to their ample supply for potential large-scale applications. However, it is still challenging to achieve highly efficient photocatalytic performance owing to their sluggish charge separation and lack of active catalytic sites. Herein, we designed and constructed a series of covalently bonded organic semiconductors to enhance water splitting and phenol degradation.
View Article and Find Full Text PDFOrg Lett
January 2025
Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, P. R. China.
Herein, a -phenylphenothiazine-based hyper-cross-linked polymer (PTH-HCP) was finely designed and constructed, which serves as a metal-free heterogeneous photocatalyst for organic transformations. Characterization experiments have shown that this polymer demonstrates outstanding stability, extensive surface area, and exceptional photoelectric response properties. Moreover, PTH-HCP showed good catalytic efficiency and recyclability in the photochemically driven difluoromethylation/cyclization reactions.
View Article and Find Full Text PDFJ Org Chem
January 2025
Key Laboratory of Biomass Green Chemical Conversion of Yunnan Provincial Education Department, Yunnan Key La-boratory of Chiral Functional Substance Research and Application, School of Chemistry & Environment, Yunnan Minzu University, Kunming 650504, P. R. China.
We report a base-promoted, metal-free multicomponent tandem reaction, involving a [4 + 1 + 1] cycloaddition process between -substituted nitroarenes, aldehydes, and ammonium salts. Modifying the substituents on the nitroaromatic compounds effectively provides structurally diverse 2-substituted and 4-alkenylquinazolines with good to excellent yields (77%-90% and quinazoline 51 examples) and high tolerance for various inorganic ammonium salts (13 examples, such as NH·HO, NHCl, and NHHF). A new method for constructing 2,4-substituted quinazoline compounds with high selectivity from simple nitrogen source compounds was developed, and the reaction can be scaled up to a gram scale.
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