5424-19-1Relevant articles and documents
Aromatization as an Impetus to Harness Ketones for Metallaphotoredox-Catalyzed Benzoylation/Benzylation of (Hetero)arenes
Chen, Ting-Wei,Cheng, Cheng-Ku,Chiu, Cheng-Chau,Huang, Pin-Gong,Lee, Shao-Chi,Lee, Yi-Hsin,Li, Li-Yun,Liao, Hsuan-Hung,Lin, Heng-Bo,Tsai, Zong-Nan,Tsao, Yong-Ting,Yang, Chung-Hsin
, (2022/01/04)
Herein we report ketones as feedstock materials in radical cross-coupling reactions under Ni/photoredox dual catalysis. In this approach, simple condensation first converts ketones into prearomatic intermediates that then act as activated radical sources for cross-coupling with aryl halides. Our strategy enables the direct benzylation/benzoylation of (hetero)arenes under mild reaction conditions with high functional group tolerance.
Photo-induced oxidative cleavage of C-C double bonds for the synthesis of biaryl methanoneviaCeCl3catalysis
Xie, Pan,Xue, Cheng,Du, Dongdong,Shi, SanShan
supporting information, p. 6781 - 6785 (2021/08/20)
A Ce-catalyzed strategy is developed to produce biaryl methanonesviaphotooxidative cleavage of C-C double bonds at room temperature. This reaction is performed under air and demonstrates high activity as well as functional group tolerance. A synergistic Ce/ROH catalytic mechanism is also proposed based on the experimental observations. This protocol should be the first successful Ce-catalyzed photooxidation reaction of olefins with air as the oxidant, which would provide inspiration for the development of novel Ce-catalyzed photochemical synthesis processes.
Decatungstate-mediated solar photooxidative cleavage of CC bonds using air as an oxidant in water
Du, Dongdong,Luo, Junfei,Shi, Sanshan,Xie, Pan,Xue, Cheng
, p. 5936 - 5943 (2021/08/23)
With the increasing attention for green chemistry and sustainable development, there has been much interest in searching for greener methods and sources in organic synthesis. However, toxic additives or solvents are inevitably involved in most organic transformations. Herein, we first report the combination of direct utilization of solar energy, air as the oxidant and water as the solvent for the selective cleavage of CC double bonds in aryl olefins. Various α-methyl styrenes, diaryl alkenes as well as terminal styrenes are well tolerated in this green and sustainable strategy and furnished the desired carbonyl products in satisfactory yields. Like heterogeneous catalysis, this homogeneous catalytic system could also be reused and it retains good activity even after repeating three times. Mechanism investigations indicated that both O2- and 1O2 were involved in the reaction. Based on these results, two possible mechanisms, including the electron transfer pathway and the energy transfer pathway, were proposed.
A Fast and General Route to Ketones from Amides and Organolithium Compounds under Aerobic Conditions: Synthetic and Mechanistic Aspects
Ghinato, Simone,Territo, Davide,Maranzana, Andrea,Capriati, Vito,Blangetti, Marco,Prandi, Cristina
, p. 2868 - 2874 (2021/01/21)
We report that the nucleophilic acyl substitution reaction of aliphatic and (hetero)aromatic amides by organolithium reagents proceeds quickly (20 s reaction time), efficiently, and chemoselectively with a broad substrate scope in the environmentally responsible cyclopentyl methyl ether, at ambient temperature and under air, to provide ketones in up to 93 % yield with an effective suppression of the notorious over-addition reaction. Detailed DFT calculations and NMR investigations support the experimental results. The described methodology was proven to be amenable to scale-up and recyclability protocols. Contrasting classical procedures carried out under inert atmospheres, this work lays the foundation for a profound paradigm shift of the reactivity of carboxylic acid amides with organolithiums, with ketones being straightforwardly obtained by simply combining the reagents under aerobic conditions and with no need of using previously modified or pre-activated amides, as recommended.
Organotellurium-catalyzed oxidative deoximation reactions using visible-light as the precise driving energy
Deng, Xin,Qian, Rongrong,Zhou, Hongwei,Yu, Lei
supporting information, p. 1029 - 1032 (2020/10/23)
Irradiated by visible light, the recyclable (PhTe)2-catalyzed oxidative deoximation reaction could occur under mild conditions. In comparison with the thermo reaction, the method employed reduced catalyst loading (1 mol% vs. 2.5 mol%), but afforded elevated product yields with expanded substrate scope. This work demonstrated that for the organotellurium-catalyzed reactions, visible light might be an even more precise driving energy than heating because it could break the Te–Te bond accurately to generate the active free radical catalytic intermediates without damaging the fragile substituents (e.g., heterocycles) of substrates. The use of O2 instead of explosive H2O2 as oxidant affords safer reaction conditions from the large-scale application viewpoint.
Visible light-driven direct synthesis of ketones from aldehydes via C[sbnd]H bond activation using NiCu nanoparticles adorned on carbon nano onions
Heydari, Akbar,Khorsandi, Zahra,Metkazini, S. Fatemeh Mohammadi,Varma, Rajender S.
, (2021/11/09)
An efficient, straightforward and high yield synthetic approach is described for the direct synthesis of diaryl ketones via the C[sbnd]H bond activation of aldehydes using NiCu nanoparticles adorned on carbon nano onions as an efficient heterogeneous catalyst under the irradiation of a mercury-vapor lamp (400 w) via simple workup. This C[sbnd]H bond activation reaction appears simple and convenient with a wide substrate scope in view of its excellent synthesis prowess as illustrated in the preparation of new-approved anti-Alzheimer and anti-HIV medicinal compounds under greener and mild reaction conditions; catalyst could be recycled and reused five times without any loss of catalytic activity.
Half-sandwich ruthenium complex containing phenyl benzoxazole structure as well as preparation method and application of half-sandwich ruthenium complex
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Paragraph 0049-0052, (2021/04/14)
The invention relates to a half-sandwich ruthenium complex containing a phenyl benzoxazole structure as well as a preparation method and application of the half-sandwich ruthenium complex. The ruthenium complex has the following structure as shown in the specification. The preparation method comprises the steps of dissolving phenyl benzoxazole, [CymRuCl2] 2 and sodium acetate in methanol at room temperature, heating the system, and continuing to react; and after the reaction is finished, standing, filtering, carrying out reduced pressure pumping on the solvent, carrying out column chromatography separation on the obtained crude product to obtain the red half-sandwich ruthenium complex containing the phenyl benzoxazole structure, and applying the red half-sandwich ruthenium complex to catalysis of oxidation of alkyl pyridine compounds to prepare nitrogen heterocyclic ketone compounds. Compared with the prior art, the preparation method provided by the invention is simple and green, the catalytic oxidation reaction can be carried out under mild conditions, and the catalyst has high stability and is not sensitive to air and water.
Copper-Catalyzed Oxidative Fragmentation of Alkynes with NFSI Provides Aryl Ketones
Chen, Hanfei,Cheng, Hao,Huang, Yifan,Jin, Chaochao,Song, Weihan,Tan, Chen,Tan, Jiajing,Tang, Lin,Yang, Fang,Zhang, Shuaifei
supporting information, (2020/11/03)
A copper-catalyzed oxidative cleavage reaction of alkynes using NFSI and TBHP was described. Various terminal and internal alkyne substrates were employed to render quick access to aryl ketone products in moderate to good yields. NFSI not only functioned as N-centered radical precursors but also engaged in the aryl group migration. Mechanistic studies also suggested the important role of water in the title reactions.
Novel synthesis method for aromatic ketone compounds
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Paragraph 0048-0050, (2020/12/08)
The invention discloses a novel method for synthesizing target aromatic ketone compounds by taking alkyne and N-fluorobenzenesulfonamide as initial raw materials of a reaction through a mechanism of catalyzing single electron transfer of alkyne breakage by copper under the action of an oxidizing agent. The method provided by the invention is wide in substrate range, and can construct different substituted aromatic ketone compounds by using fat and aromatic alkyne as substrates. In addition, the method provided by the invention has the advantages of mild reaction conditions, simple operation, product diversity, and capability of realizing large-scale production.
Silylcarboxylic Acids as Bifunctional Reagents: Application in Palladium-Catalyzed External-CO-Free Carbonylative Cross-Coupling Reactions
Li, Xiong,Xu, Jie,Li, Yue,Kramer, S?ren,Skrydstrup, Troels,Lian, Zhong
supporting information, p. 4078 - 4083 (2020/07/30)
A palladium-catalyzed external-CO-free carbonylative Hiyama-Denmark cross-coupling reaction is presented. The introduction of silylcarboxylic acids as bifunctional reagents (CO and nucleophile source) avoids the need for external gaseous CO and a silylarene coupling partner. The transformation features high functional group tolerance and it is successful with electron-rich, -neutral, and -poor aryl iodides. Stoichiometric studies and control experiments provide insight into the reaction mechanism and support the hypothesized dual role of silylcarboxylic acids. (Figure presented.).
