- Visible-Light-Induced Photocatalytic Oxidative Decarboxylation of Cinnamic Acids to 1,2-Diketones
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A concerted metallophotoredox catalysis has been realized for the efficient decarboxylative functionalization of α,β-unsaturated carboxylic acids with aryl iodides in the presence of perylene bisimide dye to afford 1,2-diketones.
- Chand, Shiv,Pandey, Anand Kumar,Singh, Rahul,Singh, Krishna Nand
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p. 6486 - 6493
(2021/05/06)
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- 1-butyl-3-methylimidazol-2-ylidene as an efficient catalyst for cross-coupling between aromatic aldehydes and N-aroylbenzotriazoles
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Cross-coupling of aromatic aldehydes with N-aroylbenzotriazoles in [Bmim]Br in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) provided an efficient procedure for the synthesis of 1,2-diarylethane-1,2-diones.
- Phungpis, Baramee,Hahnvajanawong, Viwat
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p. 651 - 657
(2021/02/27)
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- Two-Step One-Pot Synthesis of Unsymmetrical (Hetero)Aryl 1,2-Diketones by Addition-Oxygenation of Potassium Aryltrifluoroborates to (Hetero)Arylacetonitriles
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An efficient one-pot two-step procedure for the synthesis of unsymmetrical (hetero)aryl 1,2-diketones has been developed. The reaction proceeds through a palladium-catalyzed nucleophilic addition of potassium aryltrifluoroborates to aliphatic nitriles followed by a copper-catalyzed aerobic benzylic C–H oxygenation using molecular oxygen as a green oxidant. This represents the first example of the direct synthesis of unsymmetrical diaryl 1,2-diketones from arylacetonitriles. This method utilizes inexpensive, stable, nontoxic, and readily available starting materials, is highly effective in the presence of both electron-rich and electron-poor nitriles and aryltrifluoroborates, and tolerates a wide variety of functional groups. The synthetic utility of this transformation was shown by increasing the scale of the reaction and by carrying out the one-pot protocol for the preparation of quinoxaline and benzimidazole derivatives. A plausible reaction mechanism has also been proposed.
- Kumar, Yogesh,Jaiswal, Yogesh,Kumar, Amit
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p. 494 - 505
(2018/02/09)
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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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- Copper-catalyzed base-accelerated direct oxidation of C-H bond to synthesize benzils, isatins, and quinoxalines with molecular oxygen as terminal oxidant
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We describe herein an efficient and general copper (II)-catalyzed base-accelerated oxidation of the C-H bond to synthesize benzils and isatins. With similar oxidation system an efficient one-pot procedure for the synthesis of quinoxaline derivatives was realized. The two protocols feature using molecular oxygen as terminal oxidant, low catalyst loading, wide substrate scope, and high functional-group tolerance.
- Yu, Jing-Wen,Mao, Shuai,Wang, Yong-Qiang
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p. 1575 - 1580
(2015/03/14)
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- Assisted tandem catalytic cross metathesis-oxidation: In one flask from styrenes to 1,2-diketones and further to quinoxalines
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1,2-Diketones were synthesized from styrenes by combining a cross metathesis and a Ru-catalyzed alkene oxidation to an assisted tandem catalytic sequence. The synthesis relies on the use of just one metathesis precatalyst, which was in situ converted to the oxidation catalyst by addition of an alkyl hydroperoxide as a chemical trigger and oxidant. The one-flask sequence can be extended beyond 1,2-diketones to quinoxalines, by condensation of the oxidation products with ortho-phenylenediamine.
- Schmidt, Bernd,Krehl, Stefan,Hauke, Sylvia
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p. 5427 - 5435
(2013/07/25)
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- Iodine-catalyzed synthesis of 1,2-diaryldiketones by oxidative cleavage of 1,3-diaryldiketones with DMSO
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A metal-free, efficient, practical, and convenient process based on an iodine-catalyzed oxidative cleavage reaction has been developed to form 1,2-diaryldiketons in high yields from 1,3-diaryldiketones. The reaction is performed in DMSO and in air, and a mechanism was proposed according to the reaction evidence. Copyright
- Yuan, Yu,Zhu, Haitao
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experimental part
p. 329 - 333
(2012/02/04)
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- Oxidation of aromatic alkynes with nitrate radicals (NO3 ?): An experimental and computational study on a synthetically highly versatile radical
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Addition of electro- and photochemically generated nitrate radicals, NO3?, to the C?C triple bond of aromatic alkynes 9a?9h leads to formation of 1,2-diketones 10a?10h. Surprisingly, benzophenones 11a?11h are obtained as by-products, which formally result from loss of a carbon atom. Density functional studies performed with the BHandHLYP method in combination with various basis sets revealed that 1,2-diketones result from 5-endo cyclization of the initially formed vinyl radical and loss of NO?. The key step to benzophenone formation is a ?-cleavage at the stage of the vinyl radical with release of NO2?, followed by Wolff rearrangement of the resulting ?-oxo carbene. CSIRO 2007.
- Wille, Uta,Andropof, Jilliarne
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p. 420 - 428
(2008/02/11)
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- Iron(III)-ethylenediaminetetraacetic acid mediated aerobic oxidation of α-hydroxyketones: a simple and convenient synthesis of α-diketones
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Iron(III)-ethylenediaminetetraacetic acid in aqueous methanol offers a simple, environmentally acceptable synthetic tool to oxidize α-hydroxyketones α-diketones with molecular oxygen, in excellent yields and under mild conditions and without any side reactions.
- Rao, T. Venkateshwar,Dongre, Rajendra S.,Jain, Suman L.,Sain, Bir
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p. 2637 - 2642
(2007/10/03)
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- Structural Effects in Photoepoxidation Sensitized by α-Diketones
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A series of α-diketones and benzils were examined for their effectiveness as sensitizers in the photoepoxidation reaction.The reduction potentials of these α-diketones were also determined at a hanging-mercury-drop electrode.The reduction potentials of the p,p'-disubstituted-benzils were successfully correlated to the sum of the Hammett ? values.No evidence could be found that electron transfer plays an important role in the epoxidation mechanism.The mechanistic possibilities are briefly discussed.Studies of the photoepoxidation reaction in a variety of solvents have also shown that the reaction is very insensitive to solvent effects.
- Clennan, Edward L.,Speth, David R.,Bartlett, Paul D.
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p. 1246 - 1250
(2007/10/02)
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