- Rhodium-Catalyzed Aerobic Decomposition of 1,3-Diaryl-2-diazo-1,3-diketones: Mechanistic Investigation and Application to the Synthesis of Benzils
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The conversion of 1,3-diaryl-2-diazo-1,3-diketones to 1,2-daryl-1,2-diketones (benzils) is reported based on a rhodium(II)-catalyzed aerobic decomposition process. The reaction occurs at ambient temperatures and can be catalyzed by a few dirhodium carboxylates (5 mol %) under a balloon pressure of oxygen. Moreover, an oxygen atom from the O2 reagent is shown to be incorporated into the product, and this is accompanied by the extrusion of a carbonyl unit from the starting materials. Mechanistically, it is proposed that the decomposition may proceed via the interaction of a ketene intermediate resulting from a Wolff rearrangement of the carbenoid, with a rhodium peroxide or peroxy radical species generated upon the activation of molecular oxygen. The proposed mechanism has been supported by the results from a set of controlled experiments. By using this newly developed strategy, a large array of benzil derivatives as well as 9,10-phenanthrenequinone were synthesized from the corresponding diazo substrates in varying yields. On the other hand, the method did not allow the generation of benzocyclobutene-1,2-dione from 2-diazo-1,3-indandione because of the difficulty of inducing the initial rearrangement.
- Zhu, Jia-Liang,Tsai, Yi-Ting
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p. 813 - 828
(2020/12/22)
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- Visible light-induced aerobic oxidation of diarylalkynes to α-diketones catalyzed by copper-superoxo at room temperature
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We have developed the visible light induced simple copper(ii) chloride catalyzed oxidation of diarylacetylenes to α-diketones by molecular oxygen at room temperature. The in situ generated copper(ii)-superoxo complex is a light-absorbing species that oxidizes inert diarylacetylenes to α-diketones. In contrast to reported photochemical processes, the current oxidation protocol does not require any exogenous photocatalyst or radical initiator. The green chemistry metrics evaluation signifies that the E-factor for the current oxidation process is ~2.3 times better than that of reported photochemical processes. The current reaction scores 63 on the EcoScale of 0-100, indicating an adequate synthesis process. Thus, the overall oxidation process is simple, environmentally benign, and economically feasible. This journal is
- Charpe, Vaibhav Pramod,Hwang, Kuo Chu,Sagadevan, Arunachalam
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supporting information
p. 4426 - 4432
(2020/08/10)
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- Tandem and chemoselective synthesis of benzil derivatives from styrene and arene diazonium salts
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A facile and practically applied protocol for synthesis of benzil derivatives using styrene and arene diazonium salts is reported. Pd(OAc)2/SeO2 catalytic system was found to be efficient for chemoselective synthesis of benzil. Selenium dioxide works well as an oxidant under milder reaction conditions. Moderate to very good yields of the desired products were obtained.
- Jadhav, Vilas G.,Sarode, Sachin A.,Nagarkar, Jayashree M.
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supporting information
p. 1834 - 1838
(2017/04/21)
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- A benzion double-methyl ether synthesis process
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The present invention discloses a benzoin dimethyl ether synthesis process, which comprises: adding methanol, benzaldehyde, sodium cyanide and water to a reaction kettle, carrying out a condensation reaction to generate an intermediate benzoin, adding the benzoin to an oxidation kettle, carrying out an oxidation reaction to obtain dibenzoyl, adding the dibenzoyl to a synthesis kettle, adding dimethyl sulfate and solvents such as dioxane and sodium methoxide, carrying out alkali fusion, adding water after the alkali fusion, carrying out thermal insulation at a temperature of 70 DEG C, carrying out alkali crystal layering, adding water to the crystal layer, carrying out cooling crystal transition, placing into a centrifuge to dewater, carrying out water washing centrifugation to obtain a crude wet product, pouring the crude wet product into a refining kettle, adding methanol through a metering pump, heating to a temperature of 60 DEG C to dissolve, adding active carbon, carrying out decolorization, filtering after the decolorization so as to remove the active carbon, conveying the filtrate into an crystallization kettle, carrying out cooling crystallization for 3 h to obtain a wet fine product, drying the wet fine product through filtration, washing and drying three-in-one equipment to obtain the finished product, and carrying out packaging warehousing. With the synthesis process of the present invention, the effects of low raw material cost, low environmental pollution, and high finished product yield are achieved.
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Paragraph 0037; 0038; 0039
(2017/04/29)
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- Discovery of the 3-Imino-1,2,4-thiadiazinane 1,1-Dioxide Derivative Verubecestat (MK-8931)-A β-Site Amyloid Precursor Protein Cleaving Enzyme 1 Inhibitor for the Treatment of Alzheimer's Disease
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Verubecestat 3 (MK-8931), a diaryl amide-substituted 3-imino-1,2,4-thiadiazinane 1,1-dioxide derivative, is a high-affinity β-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitor currently undergoing Phase 3 clinical evaluation for the treat
- Scott, Jack D.,Li, Sarah W.,Brunskill, Andrew P. J.,Chen, Xia,Cox, Kathleen,Cumming, Jared N.,Forman, Mark,Gilbert, Eric J.,Hodgson, Robert A.,Hyde, Lynn A.,Jiang, Qin,Iserloh, Ulrich,Kazakevich, Irina,Kuvelkar, Reshma,Mei, Hong,Meredith, John,Misiaszek, Jeffrey,Orth, Peter,Rossiter, Lana M.,Slater, Meagan,Stone, Julie,Strickland, Corey O.,Voigt, Johannes H.,Wang, Ganfeng,Wang, Hongwu,Wu, Yusheng,Greenlee, William J.,Parker, Eric M.,Kennedy, Matthew E.,Stamford, Andrew W.
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p. 10435 - 10450
(2016/12/16)
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- A method for synthesizing derivatives benzil
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The invention discloses a method for synthesizing a benzil derivative. The method comprises the following steps: adding epoxy chalcone compound shown in the formula I, a Selectfluor oxidizing agent and inorganic base into a mixed solvent of acetonitrile and water, stirring for reaction for 4-8 h at 60-100 DEG C, and treating a reaction liquid obtained after the reaction is finished to prepare the benzil derivative shown in the formula II. The synthesis method has the advantages that the raw materials are cheap and easy to obtain, transition metal catalysis is not needed, the oxygen source is easy to obtain and environment-friendly, the reaction condition is mild, the target substrate can be synthesized efficiently, the universality of the functional group is good, and the operation is simple and convenient.
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Paragraph 0053-0055
(2020/02/07)
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- Selectfluor-Mediated Simultaneous Cleavage of C-O and C-C Bonds in α,β-Epoxy Ketones under Transition-Metal-Free Conditions: A Route to 1,2-Diketones
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Selectfluor-mediated simultaneous cleavage of C-O and C-C bonds in α,β-epoxy ketones has been successfully achieved under transition-metal-free conditions. The reaction gives 1,2-diketone compounds in moderate to good yields involving a ring-opening/benzoyl rearrangement/C-C bond cleavage sequence under oxidative conditions.
- Wang, Heng,Ren, Shaobo,Zhang, Jian,Zhang, Wei,Liu, Yunkui
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p. 6856 - 6863
(2015/10/06)
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- Aminocatalytic cross-coupling approach via iminium ions to different C-C bonds
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Given the attractive ability of iminium ions to functionalize molecules directly at ostensibly unreactive positions, the reactivity of iminium ions, in which an α CH2 group is replaced by C=O was explored. Background studies on the ability of such iminium cations to promote reactions via an iminium-catalyzed or iminium-equivalent pathway are apparently unavailable. Previously, tandem cross-coupling reactions were reported, in which an iminium ion undergoes nucleophilic 1,2-addition to give a putative three-component intermediate that abstracts a proton in situ and undergoes self-deamination followed by unprecedented DMSO/ aerobic oxidation to generate a-ketoamides. However, later it was observed that iminium ions can generate valuable α-ketoamides through simple aerobic oxidation. In all reactions, iminium ions were generated in situ by reaction of 2-oxoaldehydes with secondary amines.
- Mupparapu, Nagaraju,Battini, Narsaiah,Battula, Satyanarayana,Khan, Shahnawaz,Vishwakarma, Ram A.,Ahmed, Qazi Naveed
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supporting information
p. 2954 - 2960
(2015/02/05)
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- Catalyst-controlled highly selective coupling and oxygenation of olefins: A direct approach to alcohols, ketones, and diketones
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Oxygen? That's radical! A method for the direct synthesis of substituted alcohols, ketones, and diketones through a catalyst-controlled highly chemoselective coupling and oxygenation of olefins has been developed. The method is simple and practical, can be switched by the selection of different catalysts, and employs molecular oxygen as both an oxidant and a reagent. Copyright
- Su, Yijin,Sun, Xiang,Wu, Guolin,Jiao, Ning
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supporting information
p. 9808 - 9812
(2013/09/23)
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- Facile aerobic photo-oxidative synthesis of α-diketones from alkynes
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We report a useful method for facile aerobic photo-oxidative synthesis of α-diketones from alkynes with MgBr2·OEt2. This procedure provides a practical synthetic method of α-diketones using easily handled bromine sources, harmless visible light, and molecular oxygen as terminal oxidant.
- Nobuta, Tomoya,Tada, Norihiro,Hattori, Kasumi,Hirashima, Shin-Ichi,Miura, Tsuyoshi,Itoh, Akichika
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experimental part
p. 875 - 877
(2011/03/20)
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- Mild oxidation of diarylacetylenes to 1,2-diketones using oxone in trifluoroacetic acid
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A variety of 1,2-diaryldiketones were synthesized in 15-90% yields by treatment of diarylacetylenes with Oxone as the oxidant in trifluoroacetic acid. Oxidation of 1-nitro-2-(phenylethynyl) benzene and 2,4¢-(ethyne-1,2-diyl) bis(nitrobenzene) furnished 1-benzoylbenzo[c]isoxazol-3(1H)-one and benzo[c]isoxazol-3-yl(4-nitrophenyl)methanone as the major products, respectively. Georg Thieme Verlag Stuttgart.
- Chu, Jean-Ho,Chen, Yen-Ju,Wu, Ming-Jung
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experimental part
p. 2155 - 2162
(2009/12/27)
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- CONVENIENT PREPARATION OF UNSYMMETRICALLY SUBSTITUTED BENZILS BY PERMANGANATE OXIDATION OF β-OXO PHOSPHORUS YLIDES
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Oxidative cleavage of a range of ylides 4 with R1 and/or R2 being aromatic groups, using KMnO4 in a two-phase system, affords unsymmetrical benzils and 1-arylpropane-1,2-diones 5 in moderate to good yield, and the ylide formation and oxidation can be combined in a convenient one-pot method.Key words: Phosphorus ylides, oxidation, 1,2-diketones, benzils, permanganate, oxoalkylidenetriphenylphosphoranes.
- Aitken, R. Alan,Cadogan, J. I. G.,Gosney, Ian
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p. 281 - 286
(2007/10/02)
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