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Remote Trifluoromethylthiolation Enabled by Organophotocatalytic Ca??C Bond Cleavage
摘要： The first metal-free ring opening/trifluoromethylthiolation of cycloalkanols for the formation of remote C(sp3)?SCF3 bonds has been developed. A variety of trifluoromethylthiolated carbonyl compounds that are otherwise difficult to achieve were prepared in good yields under mild reaction conditions. The reaction is assumed to proceed via C?C bond cleavage of the alkoxyl radical species generated via a photoredox-enabled intramolecular proton-coupled electron transfer process, followed by trifluoromethylthiolation of the resulting C-centered radical with the N-(trifluoromethylthio)phthalimide reagent.
关键词： trifluoromethylthiolation,C?C bond cleavage,photoredox catalysis,cycloalkanols,alkoxyl radical
更新于2025-09-23 15:19:57
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Advance in carbon dots: a perspective from traditional quantum dots
摘要： Quantum dots (QDs) have been the core concept of nanoscience and nanotechnology since its inception, and play a dominant role in the development of the nano-field. Carbon dots (CDots), defined by a feature size of ?10 nm, have become a rising star in the crossing field of carbon materials and traditional QDs (TQDs). CDots own many unique structural, physicochemical and photochemical properties that render them a promising platform for biology, devices, catalysis and other applications. However, due to the complex nature of CDots, the profound understanding of the physical and chemical properties of CDots is still a great challenge. Many key issues including structure, synthesis, and optical properties are unclear, leaving opening arguments and nonuniform description of their basics. The achievements and experience of TQDs in the past four decades are expected to provide crucial values for further development of CDots. Here, we will compare the research outputs of TQDs and CDots and try to give a comprehensive picture on their differences and correlations in structure, synthesis, properties and applications. Along this way, further perspectives are given on future directions and key issues toward better understanding of the basic properties of TQDs and CDots in a unifying manner. We expect researchers in the community to foresee the great potential of CDots, and focus on the critical thinking from the development of TQDs, paying special attention to the profound principles behand the synthetic chemistry, luminescence mechanisms and applications.
关键词： Carbon dots,Quantum dots,Photochemical properties,Biology,Nanoscience,Catalysis,Devices,Nanotechnology
更新于2025-09-23 15:19:57
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Controlled Hydrogenation of Alkynes on Photogenerated Palladium Nanoparticles
摘要： A palladium nanoparticles–bisacyl-phosphine oxide composite (PdNPs@BAPO) was prepared by treatment of Pd(OAc)2 under UV irradiation using bis(mesitylcarbonyl)(phenyl)phosphine oxide as a photoinitiator (eq. 1). PdNPs@BAPO catalyzed the controlled hydrogenation of alkynes under H2 to give the corresponding (Z)-alkenes in up to 99% yield and up to 99:1 Z/E selectivity (eq. 2; 18 examples).
关键词： palladium catalysis,hydrogenation,nanoparticles,alkynes,alkenes,light-mediated synthesis
更新于2025-09-23 15:19:57
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A sola??gel synthesis to prepare size and shape-controlled mesoporous nanostructures of binary (IIa??VI) metal oxides
摘要： A base-catalyzed sol–gel approach combined with a solvent-driven self-assembly process at low temperature is augmented to make manganese oxide (Mn3O4), copper oxide (CuO), and magnesium hydroxide (Mg(OH)2) nanostructures with size- and shape-controlled morphologies. Nanostructures of Mn3O4 with either hexagonal, irregular particle, or ribbon shape morphologies with an average diameter ranged from 100 to 200 nm have been prepared in four di?erent solvent types. In all morphologies of Mn3O4, the experimental XRD patterns have indexed the nanocrystal unit cell structure to triclinic. The hexagonal nanoparticles of Mn3O4 exhibit high mesoporocity with a BET surface area of 91.68 m2 g?1 and BJH desorption average pore diameter of ～28 nm. In the preparation of CuO nanostructures, highly nanoporous thin sheets have been produced in water and water/toluene solvent systems. The simulated XRD pattern matches the experimental XRD patterns of CuO nanostructures and indexes the nanocrystal unit cell structure to monoclinic. With the smallest desorption total pore volume of 0.09 cm3 g?1, CuO nanosheets have yielded the lowest BET surface area of 18.31 m2 g?1 and a BHJ desorption average pore diameter of ～16 nm. The sol of magnesium hydroxide nanocrystals produces highly nanoporous hexagonal nanoplates in water and water/toluene solvent systems. The wide angle powder XRD patterns show well-de?ned Bragg's peaks, indexing to a hexagonal unit cell structure. The hexagonal plates show a signi?cantly high BET surface area (72.31 m2 g?1), which is slightly lower than the surface area of Mn3O4 hexagonal nanoparticles. The non-template driven sol–gel synthesis process demonstrated herein provides a facile method to prepare highly mesoporous and nanoporous nanostructures of binary (II–VI) metal oxides and their hydroxide derivatives, enabling potential nanostructure platforms with high activities and selectivities for catalysis applications.
关键词： catalysis applications,size and shape-controlled morphologies,mesoporous nanostructures,binary (II–VI) metal oxides,sol–gel synthesis
更新于2025-09-23 15:19:57
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CuIn-ethylxanthate a a??versatile precursora?? for photosensitization of graphene-quantum dots and nanocatalyzed synthesis of imidazopyridines with ideal green chemistry metrics
摘要： Recently, the development of hybrid nano catalyst involving earth abundant transition metals for photosensitization and multi-component reaction in industry and academia has been a matter of intense study. Such hybridized catalytic systems minimize the production cost and acts as a bridged system by diversifying the application in different areas. In the present study copper indium ethylxanthate was used as a versatile precursor for synthesis of colloidal chalcopyrite phase copper indium sulphide (CC-CIS NPs) in photosensitization of graphene quantum dots and reusable powdered wurzite phased copper indium sulphide nanoparticles (PW-CIS500 NPs) for selective and efficient single pot sustainable synthesis of substituted imidazopyridines via A3 coupling strategy of an aldehyde, amine and alkyne. The material was characterized by various spectroscopic techniques viz HR-TEM, PXRD, FESEM, elemental mapping studies, UV visible spectroscopy, photoluminescence, XPS, BET and ICP-OES/MS etc. Quenching of photoluminescence intensity of colloidal CuInS2 on anchoring the graphene quantum dots (GQDs) was confirmed by photosensitization of GQDs via efficient charge transfer in CIS-GQD interface. On the other hand, the PW-CIS500 NCs catalyzed A3 coupling strategy demonstrates the high catalytic efficiency for A3 coupling reaction giving substituted imidazopyridines without losing its activity and could be recycled with a total turnover number of > 210, good E-factor of 0.13 and high RME of 88%.
关键词： multicomponent reactions,heterogenous catalysis,copper indium sulphide,copper indium ethylxanthate,imidazopyridines,graphene quantum dots,charge transfer
更新于2025-09-23 15:19:57
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Photoredox Controlled ?2a??Regioselective Radical Hydroboration of Activated Alkenes with NHCa??Boranes
摘要： In this communication, we report an unprecedented β-regioselective radical inverse hydroboration (compared with ionic hydroboration) of α, β-unsaturated amides with NHC-BH3 enabled by the photoredox catalysis. The density functional theory (DFT) calculations show that the unique photoredox cycle is a key factor to control the β-regioselective radical hydroboration, which makes the energy barrier is lower than other pathways. This protocol provides a general and convenient route to construct a wide range of structurally diverse β-borylated amides in synthetically useful yields under mild conditions.
关键词： Regioselective hydroboration,Photoredox catalysis,Radical borylation,Umpolung
更新于2025-09-23 15:19:57
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Light-Controlled Nanoparticle Collision Experiments
摘要： Electrochemical monitoring of catalytically amplified collisions of individual metal nanoparticles (NP) with ultramicroelectrodes (UME) has been extensively used to study electrocatalysis, mass-transport, and charge-transfer processes at the single NP level. More recently, photoelectrochemical collision experiments were carried out with semiconductive NPs. Here we introduce two new types of light-controlled nano-impact experiments. The first experiment involves localized photodeposition of catalyst (Pt) on TiO2 NPs with a glass-sheathed carbon fiber simultaneously serving as the light guide and collector UME. The collisions of in situ prepared Pt@TiO2 NPs with the carbon surface produced blips of water oxidation current, while the activity of pristine TiO2 NPs was too low to yield measurable signal. In another experiment, collisions of catalytic (Ir oxide) NPs with the semiconductor (Nb doped n-type TiO2 rutile single crystal) electrode are monitored by measuring the photocurrent of water oxidation.
关键词： electrochemical monitoring,catalysis,photoelectrochemical collision,nanoparticles,water oxidation
更新于2025-09-23 15:19:57
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Aerobic α‐Oxidation of N‐Substituted Tetrahydroisoquinolines to Dihydroisoquinolones via Organo‐photocatalysis
摘要： An efficient visible-light-induced α-oxidation of N-substituted tetrahydroisoquinolines to dihydroisoquinolones has been developed using eosin Y as an organo-photocatalyst and oxygen as a green oxidant. The reactions were carried out under mild reaction conditions; the desired dihydroisoquinolones were obtained in up to 96% yield at room temperature under oxygen atmosphere. This transformation provides a convenient route to dihydroisoquinolones with a wide range of substrates.
关键词： photoredox catalysis,lactams,dihydroisoquinolones,aerobic oxidation
更新于2025-09-23 15:19:57
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Decarboxylative Heck Coupling via a Cobalt/Photoredox Catalysis
摘要： The authors report a synthesis of olefins through a photoinduced decarboxylative Heck-type coupling. The method uses alkyl carboxylic acids, which are one of the most ubiquitous building blocks. Based on DFT calculations, a radical mechanism has been proposed. Over 90 examples containing a huge variety of functional groups have been prepared in high yields.
关键词： Heck coupling,cobalt catalysis,photoredox catalysis
更新于2025-09-19 17:15:36
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A review on sustainable routes of synthesis and applications of Cuprous Oxide Nanoparticles and their Nanocomposites.
摘要： Nature acts like a “Bio-Laboratory” consisting of plants, algae, fungi, yeast etc. which are composed of bio-molecules. These naturally occurring bio-molecules play a vital role in the synthesis of Cuprous oxide (Cu2O) nanoparticles (NPs) and their nanocomposites (NCs) with distinct shapes and sizes, thereby acting as a driving force for designing safer, greener and sustainable routes using less hazardous chemicals. The present review focuses on the eco-friendly protocols for synthesis of Cu2O NPs and their NCs, characterisation techniques and various applications in organic catalysis, biosensing, environmental remediation and medicinal chemistry. The pivotal role of Cu2O NPs and their NCs in catalysing coupling reactions (C-C and C-N), multicomponent, oxidation-reduction and heterocyclic reactions have been higlighted. It emphasises its role in sustainability of the environment and its range of versatility in heterogenous catalysis. Furthermore, their use in biosensing (electrochemical detection) generates special interest in bioscience and clinical diagnosis. Their significance ensures to build a bridge between academic research and safety of the surroundings.
关键词： green chemistry,medicinal applications,biogenic synthesis,environmental remediation,biosensing,catalysis,Cuprous oxide nanoparticles
更新于2025-09-19 17:15:36