- Decarboxylative Oxyacyloxylation of Propiolic Acids: Construction of Alkynyl-Containing α-Acyloxy Ketones
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Novel decarboxylative oxyacyloxylation of propiolic acids has been developed. This reaction provides an efficient access to alkynyl-containing α-acyloxy ketones from readily available starting materials and exhibits significant functional group tolerance. Furthermore, oxyacyloxylation of terminal alkynes and aliphatic propiolic acids was also developed. A possible reaction mechanism is proposed based on mechanistic studies.
- Chen, Xin,Xin, Yangchun,Zhao, Zhi-Wei,Hou, Yu-Jian,Wang, Xiang-Xiang,Xia, Wen-Jin,Li, Ya-Min
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p. 8216 - 8225
(2021/06/28)
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- Sulfur-mediated difunctionalization of internal and terminal alkynes for the synthesis of α-acetoxy ketones
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The sulfur-mediated difunctionalization of alkynes is reported to give α-acetoxy ketones in a one-pot operation under mild conditions with 19–92% yield. By using wet potassium acetate as both the aqueous base and nucleophilic reagent, both terminal alkynes and internal alkynes could be converted into the α-acetoxy ketone products.
- Li, Pingfan,Zhang, Zhong
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- Oxidative α-Acetoxylation of a β-Oxime Ester with (Diacetoxyiodo)benzene Catalyzed by ScIII Salts: An Approach to the Docetaxel Side Chain
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Hypervalent iodine(III) compounds have emerged as reagents of choice for α-oxidation of various ketones under mild reaction conditions. We report herein a simple method for α-hydroxylation of a β-oxime ester, which involves an oxidative α-acetoxylation us
- Miyamoto, Kazunori,Hoque, Md. Mahbubul,Senoh, Yuhki,Ali, Mohammad Idrish,Nemoto, Hisao,Mandai, Tadakatsu
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supporting information
p. 2841 - 2845
(2018/06/21)
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- PhI(OAc)2-promoted umpolung acetoxylation of enamides for the synthesis of α-acetoxy ketones
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Umpolung is a fundamental concept in organic chemistry, which provides an alternative strategy for the synthesis of target compounds which were not easily accessible by conventional methods. Herein, a mild and efficient PhI(OAc)2-promoted umpolung acetoxylation reactions of enamides was developed for the synthesis of α-acetoxy ketones. The reaction tolerates a wide range of functional groups and affords α-acetoxy ketones in good to excellent yields. PhI(OAc)2 serves as a source of acetoxy in the reaction.
- Chen, Ming,Zhang, Wei,Ren, Zhi-Hui,Gao, Wen-Yun,Wang, Yao-Yu,Guan, Zheng-Hui
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p. 761 - 768
(2017/06/05)
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- Novel and efficient transformation of enamides into α-acyloxy ketones via an acyl intramolecular migration process
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Hydrogen peroxide and anhydride mediated transformation of enamides to afford substituted α-acyloxy ketones is described. This transition-metal-free cascade reaction has a broad substrate scope and high efficiency. The acyl intramolecular migration procedure successfully achieved this acyloxylation process under mild conditions and increased the atom efficiency.
- Zhou, Xiaoqiang,Ma, Haojie,Cao, Jinhui,Liu, Xingxing,Huang, Guosheng
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supporting information
p. 10070 - 10073
(2016/11/06)
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- Synthesis of α-hydroxyacetophenones
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A general method for the preparation of α-hydroxyacetophenones is presented. Functionalized arylmagnesium species are transmetalated to the corresponding arylzinc intermediates, which undergo Cu(I)-catalyzed reaction with acetoxyacetyl chloride. Acidic hy
- McLaughlin, Mark,Belyk, Kevin M.,Qian, Gang,Reamer, Robert A.,Chen, Cheng-Yi
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experimental part
p. 5144 - 5148
(2012/07/03)
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- Iron-catalyzed ketonization of 2-aryl-1,1-dibromoalkenes with KOAc: Synthesis of α-acetoxy aryl ketones via a Michael-like addition process
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A novel and convenient iron-catalyzed ketonization of 2-aryl-1,1- dibromoalkenes with KOAc has been achieved. A series of α-acetoxy aryl ketones were prepared with moderate yields via 2-carbon position functionalization of 2-aryl-1,1-dibromoalkenes.
- Zhao, Ming,Kuang, Chun Xiang,Cheng, Xue Zhi,Yang, Qing
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experimental part
p. 571 - 574
(2012/01/13)
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- Biocatalytic reduction of prochiral aromatic ketones to optically pure alcohols by a coupled enzyme system for cofactor regeneration
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A simple, highly efficient, and economical biphasic cell-free system was developed for biocatalytic reduction of prochiral aromatic ketones to furnish enantiopure alcohols. This system is characterized by using endogenous enzymes of the cell-free extract to form enzyme-coupled NADPH recycling system. Besides, it offered much higher productivity than whole cells and greatly simplified the preparation process of biocatalysts in comparison with isolated enzymes. Various prochiral aromatic ketones, especially α-substituted acetophenone derivatives, were reduced to chiral alcohols with excellent enantiomeric excess (ee) and moderate to good yield by this cell-free system.
- Yan, Zhen,Nie, Yao,Xu, Yan,Liu, Xiang,Xiao, Rong
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supporting information; experimental part
p. 999 - 1002
(2011/03/21)
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- Methods and Compositions for Treatment of Scleritis and Related Disorders
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The present teachings relate to the field of anti-inflammatory substances and more particularly to compounds that are useful for the treatment of scleritis, a scleritis symptom, or a scleritis-related disorder. In one aspect, methods of treating scleritis, a scleritis symptom, or a scleritis-related disorder generally include administering to a subject a compound of Formula I: or a pharmaceutically acceptable salt, hydrate or ester thereof, wherein W1, W2, R1, L, X, Y, Z, and n1 are defined as described herein.
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Page/Page column 14
(2008/12/05)
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- An efficient method for the α-acetoxylation of ketones
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α-Acetoxylation of ketones catalyzed by iodobenzene using 30% aqueous hydrogen peroxide and acetic anhydride as the oxidant is an effective and economical method for the preparation of a-acetoxy ketones. The reaction gave the products in good yields witho
- Sheng, Jinmei,Li, Xiaolong,Tang, Mingfang,Gao, Botao,Huang, Guosheng
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p. 1165 - 1168
(2008/02/03)
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- Synthesis and biological evaluation of quinoline salicylic acids as P-selectin antagonists
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Leukocyte recruitment of sites of inflammation and tissue injury involves leukocyte rolling along the endothelial wall, followed by firm adherence of the leukocyte, and finally transmigration of the leukocyte across cell junctions into the underlying tissue. The initial rolling step is mediated by the interaction of leukocyte glycoproteins containing active moieties such as sialyl Lewisx (sLex) with P-selectin expressed on endothelial cells. Consequently, inhibition of this interaction by means of a small molecule P-selectin antagonist is an attractive strategy for the treatment of inflammatory diseases such as arthritis. High-throughput screening of the Wyeth chemical library identified the quinoline salicylic acid class of compounds (1) as antagonists of P-selectin, with potency in in vitro and cell-based assays far superior to that of sLex. Through iterative medicinal chemistry, we identified analogues with improved P-selectin activity, decreased inhibition of dihydrooratate dehydrogenase, and acceptable CYP profiles. Lead compound 36 was efficacious in the rat AIA model of rheumatoid arthritis.
- Kaila, Neelu,Janz, Kristin,DeBernardo, Silvano,Bedard, Patricia W.,Camphausen, Raymond T.,Tam, Steve,Tsao, Desirée H.H.,Keith Jr., James C.,Nickerson-Nutter, Cheryl,Shilling, Adam,Young-Sciame, Ruth,Wang, Qin
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- Iodobenzene-catalyzed α-acetoxylation of ketones. In situ generation of hypervalent (diacyloxyiodo)benzenes using m-chloroperbenzoic acid
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Reported here for the first time is the iodobenzene-catalyzed α-oxidation of ketones, in which diacyloxy(phenyl)-λ3-iodanes generated in situ act as real oxidants of ketones and m-chloroperbenzoic acid serves as a terminal oxidant. Oxidation of a ketone with m-chloroperbenzoic acid in acetic acid in the presence of a catalytic amount of iodobenzene, BF3·Et2O, and water at room temperature under argon affords an α-acetoxy ketone in good yield. p-Methyl- and p-chloroiodobenzene also serve as efficient catalysts in this direct oxidation. We found that when the reaction was carried out in the absence of a catalytic amount of iodobenzene, Baeyer-Villiger oxidation of a ketone took place. It is noted that use of water and BF3·Et2O is crucial to the success of this α-acetoxylation. Copyright
- Ochiai, Masahito,Takeuchi, Yasunori,Katayama, Tomoko,Sueda, Takuya,Miyamoto, Kazunori
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p. 12244 - 12245
(2007/10/03)
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- Methods and compositions for selectin inhibition
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The present invention relates to the field of anti-inflammatory substances, and more particularly to novel compounds that act as antagonists of the mammalian adhesion proteins known as selectins. In some embodiments, methods for treating selectin mediated disorders are provided which include administration of compound of Formula I: wherein the constituent variables are defined herein.
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Page/Page column 15
(2008/06/13)
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- Chemoenzymatic synthesis of enantiomerically pure terminal 1,2-diols
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A new practical method for the enzymatic synthesis of 1,2-diols has been developed by employing a lipase catalyzed one-pot transesterification protocol. A series of substituted α-acetoxyphenylethanones 3a-g have been reduced to the corresponding alcohols under mild conditions employing sodium borohydride and moist neutral alumina, and further subjected for lipase catalyzed irreversible transesterification in the same pot to give mono- and diacetate diols (R)-4 and (S)-5, which on hydrolysis afforded terminal 1,2-diols, (R)- and (S)-6 in high enantiomeric excess.
- Kamal, Ahmed,Sandbhor, Mahendra,Ahmed, Kaleem,Adil,Shaik, Ahmad Ali
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p. 3861 - 3866
(2007/10/03)
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- Synthesis of α-acetoxy and formyloxy ketones by thallium(III) promoted α-oxidation
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Treatment of ketones with thallium(III) triflate in amide solvents at 60°C for 30 min followed by addition of small amounts of H2O cleanly provided the corresponding α-acyloxy ketones.
- Lee,Jin,Choi
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p. 956 - 957
(2007/10/03)
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- Metal-Metal Exchange of α-Metallo Ketones. Novel Formation of α-Acyl Anion and α-Keto Carbonium Ion Equivalents from (Aryl)phenacyl TlIII, PbIV, and HgII Systems
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The novel class of α-metallo ketones RCOCH2TlIIItolyl(OCOCF3) where R = phenyl, substituted phenyl, thienyl, pyridinyl, and tert-butyl have been synthesized and characterized by 1H NMR and 13C NMR.These compounds serve as anion equivalents in the TiCl4-mediated aldol condensation.Metal-metal exchange with iodosylbenzene or lead tetraacetate leads to α-nucleophilic substitution derived from the formal α-keto carbonium ion equivalent.The corresponding p-CH3OC6H4COCH2PbIVC6H4OCH3-p-(OCOCH3)2 and (p-CH3OC6H4COCH2)2HgII analogues were synthesized and shown to likewise behave as either enolate anion or α-keto carbonium ion equivalents upon metal-metal exchange with TiIV, PbIV, or IIII.The importance of this work is that the range of reactivity of α-metallo ketones may be selectively adjusted by metal-metal or metal-metalloid exchange.
- Moriarty, Robert M.,Penmasta, Raju,Prakash, Indra,Awasthi, Alok K.
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p. 1022 - 1025
(2007/10/02)
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- SYNTHESIS OF 1,4-DIKETONES BY THE COUPLING REACTION OF TRIMETHYLSILYL ENOL ETHERS WITH LEAD TETRAACETATE
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Synthesis of 1,4-diketones in good yields was achieved by the coupling reaction of the trimethylsilyl enol ethers of acetophenone,thiophene or furan with lead tetraacetate in dry dichloromethane and tetrahydrofuran at -78 degC.
- Moriarty, Robert M.,Penmasta, Raju,Prakash, Indra
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p. 873 - 876
(2007/10/02)
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- α-METHOXY KETONES BY THE REACTION OF TRIMETHYLSILYL ENOL ETHERS WITH LEAD TETRAACETATE IN METHANOL
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Trimethylsilyl enol ethers of acetophenone, 2-acetylthiophene and 2-acetylfuran react with lead tetraacetate in methanol at room temperature to give the α-methoxy ketones in good yields.
- Moriarty, Robert M.,Prakash, Indra,Penmasta, Raju
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p. 709 - 714
(2007/10/02)
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