- Ultrasound-assisted tandem reaction of alkynes and trihaloisocyanuric acids by thiourea as catalyst in water
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With water as the sole solvent, a green and efficient method has been developed for the synthesis of various α,α-dihaloketones via ultrasound assisted p-tolylthiourea catalyzed tandem reaction of alkynes with trihaloisocyanuric acids. This synthetic route
- Zhang, Xingyu,Wu, Yundong,Zhang, Ya,Liu, Huilan,Xie, Ziyu,Fu, Shengmin,Liu, Fang
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Read Online
- Access to α,α-dihaloacetophenones through anodic C[dbnd]C bond cleavage in enaminones
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We have developed a method to synthesize α,α-dihaloketones under electrochemical conditions. In this reaction, the Cl- or Br- is oxidized to Cl2 or Br2 at the anode, which undergoes two-step addition reactions with the N,N-dimethyl enaminone, and finally breaks C[dbnd]C of the N,N-dimethyl enaminone to generate α,α-dihaloketones. The electrosynthesis reaction can be conveniently carried out in an undivided electrolytic cell at room temperature. In addition, various functional groups are compatible with this green protocol which can be applied simultaneously to the gram scale without significantly lower yield.
- Zhang, Zhenlei,Yang, Jiusi,Wu, Kairui,Yu, Renjie,Bu, Jiping,Huang, Zijun,Li, Shaoke,Ma, Xiantao
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supporting information
(2021/12/20)
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- Method for preparing alpha,alpha-dichloroketone under solvent-free condition
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The invention provides a method for synthesizing an alpha,alpha-dichloroketone compound by taking methyl ketone and sulfonyl chloride as raw materials. The method comprises the following steps: heating a reaction mixture of methyl ketone and sulfonyl chloride to 80 DEG C under a dry air condition, stirring for 4-8 hours, after the reaction is finished, removing sulfonyl chloride from the obtained mixture, and carrying out silica gel column chromatography separation by taking ethyl acetate-hexane as an eluent to obtain the alpha,alpha-dichloroketone compound. The synthesis method provided by the invention has the advantages of extremely high chemical reactivity and selectivity, simple and easily available raw materials, low price, simple operation, no need of any catalyst and solvent, reduction of the synthesis cost and the pollution of organic solvents to the environment, greenness, economy and the like.
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Page/Page column 5
(2021/06/21)
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- Solvent-free preparation of α,α-dichloroketones with sulfuryl chloride
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An efficient and facile method is reported for the synthesis of a series of α,α-dichloroketones. The direct dichlorination of methyl ketones and 1,3-dicarbonyls using an excess amount of sulfuryl chloride affords the corresponding gem-dichloro compounds in moderate to excellent yields. Moreover, the protocol features high yields, broad substrate scope, and simple reaction conditions without using any catalysts and solvents.
- Tu, Dewei,Luo, Juan,Jiang, Wengao,Tang, Qiang
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supporting information
(2021/09/15)
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- Dichloroacetophenones targeting at pyruvate dehydrogenase kinase 1 with improved selectivity and antiproliferative activity: Synthesis and structure-activity relationships
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Dichloroacetophenone is a pyruvate dehydrogenase kinase 1 (PDK1) inhibitor with suboptimal kinase selectivity. Herein, we report the synthesis and biological evaluation of a series of novel dichloroacetophenones. Structure-activity relationship analyses (SARs) enabled us to identify three potent compounds, namely 54, 55, and 64, which inhibited PDK1 function, activated pyruvate dehydrogenase complex, and reduced the proliferation of NCI-H1975 cells. Mitochondrial bioenergetics assay suggested that 54, 55, and 64 enhanced the oxidative phosphorylation in cancer cells, which might contribute to the observed anti-proliferation effects. Collectively, these results suggested that 54, 55, and 64 could be promising compounds for the development of potent PDK1 inhibitors.
- Zhang, Shao-Lin,Yang, Zheng,Hu, Xiaohui,Tam, Kin Yip
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supporting information
p. 3441 - 3445
(2018/09/29)
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- One-pot dichlorinative deamidation of primary β-ketoamides
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An approach to the dichlorinative deamidation of primary β-ketoamides through ketonic cleavage is described, and a series of α,α-dichloroketones were furnished mostly in the presence of TEMPO. Based on control experiments, a mechanism involving tandem dichlorination and deamidation is proposed to interpret the observed reactivity.
- Zheng, Congke,Zhang, Xiaohui,Ijaz Hussain, Muhammad,Huang, Mingming,Liu, Qing,Xiong, Yan,Zhu, Xiangming
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p. 574 - 577
(2017/01/16)
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- Method for removal of methanamide by dichlorination
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A method for removal of methanamide by dichlorination is disclosed, according to the method, a finished product is obtained by removal of methanamide by dichlorination by one-step-reaction of various beta-carbonyl amide derivatives as raw materials, 2,2,6,6-Tetramethylpiperidinooxy (TEMPO) and an alkali as additives and N-chlorosuccinimide as a reagent in a reaction solvent, and then concentration and purification. According to the method, synthesis of an alpha-dichloroacetophenone derivative can be realized for the first time by a method of removal of methanamide by fracturation of carbon-carbon single bond. The method is novel and unique, has certain universality, is mild in reaction conditions, low in requirement of production equipment, and simple in technology, has the advantages of high efficiency, simple operation, high safety, economy and environmentally-friendliness; high-quality diverse alpha-dichloroacetophenone derivative products can be prepared by the method, and the products prepared by the method are important drug synthesis intermediates and material intermediates, can be widely used in the synthesis of heterocycles, unsaturated acids, acetylene alcohols and other compounds and cyclopropanation, and have wide market prospects.
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Paragraph 0020-0025; 0050; 0051; 0052; 0053; 0054
(2017/10/12)
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- Expanding the scope of alcohol dehydrogenases towards bulkier substrates: Stereo- and enantiopreference for α,α-dihalogenated ketones
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Alcohol dehydrogenases (ADHs) were identified as suitable enzymes for the reduction of the corresponding α,α-dihalogenated ketones, obtaining optically pure β,β-dichloro- or β,β-dibromohydrins with excellent conversions and enantiomeric excess. Among the different biocatalysts tested, ADHs from Rhodococcus ruber (ADH-A), Ralstonia sp. (RasADH), Lactobacillus brevis (LBADH), and PR2ADH proved to be the most efficient ones in terms of activity and stereoselectivity. In a further study, two racemic α-substituted ketones, namely α-bromo- α-chloro- and α-chloro-α-fluoroacetophenone were investigated to obtain one of the four possible diastereoisomers through a dynamic kinetic process. In the case of the brominated derivative, only the (1R)-enantiomer was obtained by using ADH-A, although with moderate diastereomeric excess (>99 % ee, 63 % de), whereas the fluorinated ketone exhibited a lower stereoselectivity (up to 45 % de). Bulking up: A series of β,β-dihalohydrins are obtained through alcohol dehydrogenase (ADH) catalyzed bioreduction of the synthesized α,α-dihalogenated ketones. Two racemic acetophenone derivatives are also subjected to this protocol to obtain stereoenriched alcohols through dynamic kinetic resolution (DKR).
- Kedziora, Kinga,Bisogno, Fabricio R.,Lavandera, Ivan,Gotor-Fernandez, Vicente,Montejo-Bernardo, Jose,Garcia-Granda, Santiago,Kroutil, Wolfgang,Gotor, Vicente
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p. 1066 - 1072
(2014/05/06)
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- α-Halogenation of carbonyl compounds: Halotrimethylsilane-nitrate salt couple as an efficient halogenating reagent system
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A mixture of chloro/bromotrimethylsilane and nitrate salt is found to be an effective reagent system for the α-chlorination/bromination of carbonyl compounds. The reaction occurs under mild conditions yielding the products in moderate to good yields.
- Prakash, G.K. Sxurya,Ismail, Rehana,Garcia, Jessica,Panja, Chiradeep,Rasul, Golam,Mathew, Thomas,Olah, George A.
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experimental part
p. 1217 - 1221
(2011/03/22)
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- INVESTIGATIONS ON REACTIONS OF CHLORINE DIOXIDE AND SODIUM CHLORITE WITH ORGANIC COMPOUNDS. PART XXXV. REACTIONS OF CHLORINE DIOXIDE WITH RING-SUBSTITUTED STYRENES
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Reactions of chlorine dioxide with ring substituted styrenes (1a-n) in carbon tetrachloride at 52-54 deg C were studied.The reaction products were isolated and characterised.It has been found that methyl-, chloro-, nitrostyrenes and 4-methoxystyrene are attacked by chlorine dioxide exclusively on the vinyl group, to yield the corresponding α-chloroacetophenones (2), diastereoisomers of β-chlorostyrene (6,7), oxidation products (8,9) and some polymers.Oxidation of its phenolic hydroxyl groups and vinyl polymerization took place in hydroxystyrenes.
- Kwiecien, Halina,Jalowiczor, Jozef
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p. 811 - 824
(2007/10/02)
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