- Influence of Steric Effect on the Pseudo-Multicomponent Synthesis of N-Aroylmethyl-4-Arylimidazoles
-
A pseudo-three-component synthesis of N-aroylmethylimidazoles 3 with three new C–N bonds formed regioselectively under microwave conditions was developed. Products were obtained by reacting two equivalents of aroylmethyl bromide (ArCOCH2 Br, 1) with the appropriate amidine salt (RCN2 H3.HX, 2) and with K2 CO3 as a base in acetonitrile. The bicomponent reaction also occurred, giving the expected 4(5)-aryl-1H-imidazoles 4. Notably, the ratio of products 3 and 4 is governed by steric factors of the amidine 2 (i.e., R = H, CH3, Ph). Therefore, a computational study was carried out to understand the reaction course regarding product ratio (3/4), regioselectivity, and the steric effects of the amidine substituent group.
- Elejalde-Cadena, Nerith Rocio,García-Olave, Mayra,Figueroa, David,Vidossich, Pietro,Miscione, Gian Pietro,Portilla, Jaime
-
-
- Decarboxylative Oxyacyloxylation of Propiolic Acids: Construction of Alkynyl-Containing α-Acyloxy Ketones
-
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
-
p. 8216 - 8225
(2021/06/28)
-
- Imidazolium-Based Ionic Network as a Robust Heterogeneous Catalyst in Synthesis of Phenacyl Derivatives
-
A new imidazolium-based poly(ionic liquid) has been synthesized and used as a robust heterogeneous catalyst for the preparation of phenacyl derivatives by an SN2 reaction of different phenacyl bromides with a broad range of nucleophiles. The products are obtained in high yields under mild conditions. The catalyst can be recycled efficiently.
- Kakesh,Sayyahi,Badri,Tahanpesar
-
p. 1218 - 1220
(2019/07/16)
-
- Metal-Free Amidation Reactions of Terminal Alkynes with Benzenesulfonamide
-
A novel and efficient approach has been developed to synthesize α-sulfonylamino ketones through the reaction between terminal alkynes and sulfonamides under ambient air using PIDA (diacetoxy iodobenzene). A library of α-sulfonylamino ketone derivatives having a variety of substituents has been synthesized. A plausible reaction pathway has been predicted. This reaction offers a broad substrate scope, metal-free synthesis, excellent regioselectivity, easily accessible reactants, and room temperature reaction conditions under ambient air and is operationally simple. A gram-scale synthesis demonstrates the potential applications of the present method. In addition, we have also synthesized α-acetoxy ketones in the case of absence of sulfonamide.
- Mahato, Sachinta,Santra, Sougata,Zyryanov, Grigory V.,Majee, Adinath
-
-
- Amino propylene glycol derivatives, its preparation method and its pharmaceutical composition and use thereof
-
The invention discloses a class of amino propanediol derivatives, a preparation method, drug compositions and uses thereof, and particularly relates to a class of new immunoloregulation agents represented by a general formula (I), a preparation method, drug compositions containing the immunoloregulation agents, and especially uses of the immunoloregulation agents as immunoloregulation drugs. The compound with characteristics of excellent treatment effect and low toxicity can be used in the fields of immunologic derangement and immunosuppression, and can further be used for treatment of hypoimmunity, organ transplant rejection and autoimmune diseases. The formula I is defined in the instruction.
- -
-
Paragraph 0174; 0177; 0178; 0179
(2018/11/22)
-
- PhI(OAc)2-promoted umpolung acetoxylation of enamides for the synthesis of α-acetoxy ketones
-
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
-
p. 761 - 768
(2017/06/05)
-
- Novel and efficient transformation of enamides into α-acyloxy ketones via an acyl intramolecular migration process
-
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
-
supporting information
p. 10070 - 10073
(2016/11/06)
-
- Integration of aqueous biphasic with magnetically recyclable systems: Polyethylene glycol-grafted Fe3O4 nanoparticles catalyzed phenacyl synthesis in water
-
The present work trends to define an efficient phenacyl catalytic synthesis method employing a new nano-magnetite-supported organocatalyst. Polyethylene glycol (PEG) was bonded successfully onto silica coated ferrite and the resultant nanoparticles (PEG@SiO2@Fe3O4) characterized by fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM), thermal gravimetric analysis (TGA), vibrating sample magnetometry (VSM), energy dispersive X-ray analysis (EDAX) and X-ray diffraction (XRD) that exhibited a good catalytic activity in the reaction. The nanoparticles could be easily separated from the reaction mixture by an external magnet and reused in seven reaction cycles without significant loss of activity.
- Amini, Atefeh,Sayyahi, Soheil,Saghanezhad, Seyyed Jafar,Taheri, Narges
-
-
- Iron-Catalyzed Dioxygenation of Alkenes and Terminal Alkynes by using (Diacetoxyiodo)benzene as Oxidant
-
An iron-catalyzed syn-diacetoxylation of alkenes and 1,2-oxyacetoxylation of terminal alkynes has been developed using (diacetoxyiodo)benzene as oxidant. A broad range of internal and terminal alkenes, including electron-rich as well as electron-deficient alkenes, gave the desired products in good to excellent yields with high diastereoselectivity (up to >99:1 dr). In addition the high catalytic activity of iron catalysis for the 1,2-oxyacetoxylation of terminal alkynes is also reported. The roles of catalyst, oxidant and other reaction parameters were evaluated for activation of the unsaturated bond.
- Srinivas,Rawat, Vikas S.,Sreedhar, Bojja
-
supporting information
p. 3587 - 3596
(2016/01/25)
-
- Synthesis, characterization and application of β-cyclodextrin-silica nanocomposite as potential microvessel in nucleophilic substitution reaction of phenacyl halides
-
In the present study, β-cyclodextrin-silica hybrid is synthesized as a novel, efficient and eco-friendly microvessel and solid-liquid phase-transfer catalyst. This molecular host system was applied for nucleophilic substitution reaction of phenacyl halide
- Kiasat, Ali Reza,Nazari, Simin
-
p. 429 - 438
(2014/01/06)
-
- Straightforward and highly efficient synthesis of α-acetoxy ketones through gold-catalyzed intermolecular oxidation of terminal alkynes
-
A variety of terminal alkynes were efficiently converted into the corresponding α-acetoxy ketones through gold-catalyzed intermolecular oxidation in the presence of 8-methylquinoline 1-oxide as the oxidant. The reaction probably proceeds through an α-oxo gold carbene intermolecular O-H insertion.
- Wu, Chao,Liang, Zhiwu,Yan, Dong,He, Weimin,Xiang, Jiannan
-
p. 2605 - 2611
(2013/09/24)
-
- Activity of 6-aryl-pyrrolo[2,3-d]pyrimidine-4-amines to Tetrahymena
-
A series 6-aryl-pyrrolo[2,3-d]pyrimidine-4-amines (43 compounds), some of which are epidermal growth factor tyrosine kinase inhibitors, were tested for their protozoal toxicity using an environmental Tetrahymena strain as model organism. The protozoacidal activity of the analogues was found to be highly dependent on a 4-hydroxyl group at the 6-aryl ring, and a chiral 1-phenylethanamine substituent in position 4. Further, the potency was affected by the aromatic substitution pattern of the phenylethanamine: the unsubstituted, the meta-fluoro and the para-bromo substituted derivatives had the lowest minimum protozoacidal concentrations (8-16 μg/mL). Surprisingly, both enantiomers were found to have high potency suggesting that this compound class could have several modes of action. No correlation was found between the compounds protozoacidal activity and the in vitro epidermal growth factor receptor tyrosine kinase inhibitory potency. This suggests that the observed antimicrobial effects are related to other targets. Testing towards a panel of kinases indicated several alternative modes of action.
- Kaspersen, Svein Jacob,Hoff, Bard Helge,Sundby, Eirik,Charnock, Colin
-
p. 35 - 41,7
(2020/07/30)
-
- β-cyclodextrin immobilized onto dowex resin: A unique microvessel and heterogeneous catalyst in nucleophilic substitution reactions
-
The catalytic activity of β-cyclodextrin immobilized on Dowex resin as an efficient solid-liquid phase transfer catalyst was developed for the synthesis of alkyl thiocyanates and phenacyl derivatives in water. The nucleophilic substitution reactions were performed under mild reaction condition and gave the products in excellent yields. Furthermore, the catalyst could be recycled by facile separation without any loss of activity.
- Kiasat, Ali Reza,Zarinderakht, Nasrollah,Sayyahi, Soheil
-
experimental part
p. 699 - 702
(2012/05/05)
-
- Iron-catalyzed ketonization of 2-aryl-1,1-dibromoalkenes with KOAc: Synthesis of α-acetoxy aryl ketones via a Michael-like addition process
-
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
-
experimental part
p. 571 - 574
(2012/01/13)
-
- A sustainable byproduct catalyzed domino strategy: Facile synthesis of α-formyloxy and acetoxy ketones via iodination/nucleophilic substitution/hydrolyzation/oxidation sequences
-
The sustainable byproduct catalyzed domino strategy has been performed for the facile synthesis of α-formyloxy and acetoxy ketones via iodination/nucleophilic substitution/hydrolyzation/oxidation sequences from simple and readily available aromatic ketone
- Zhu, Yan-Ping,Gao, Qing-He,Lian, Mi,Yuan, Jing-Jing,Liu, Mei-Cai,Zhao, Qin,Yang, Yan,Wu, An-Xin
-
supporting information; experimental part
p. 12700 - 12702
(2012/01/03)
-
- Switching reversibility to irreversibility in glycogen synthase kinase 3 inhibitors: Clues for specific design of new compounds
-
Development of kinase-targeted therapies for central nervous system (CNS) diseases is a great challenge. Glycogen synthase kinase 3 (GSK-3) offers a great potential for severe CNS unmet diseases, being one of the inhibitors on clinical trials for different tauopathies. Following our hypothesis based on the enhanced reactivity of residue Cys199 in the binding site of GSK-3, we examine here the suitability of phenylhalomethylketones as irreversible inhibitors. Our data confirm that the halomethylketone unit is essential for the inhibitory activity. Moreover, addition of the halomethylketone moiety to reversible inhibitors turned them into irreversible inhibitors with IC50 values in the nanomolar range. Overall, the results point out that these compounds might be useful pharmacological tools to explore physiological and pathological processes related to signaling pathways regulated by GSK-3 opening new avenues for the discovery of novel GSK-3 inhibitors.
- Perez, Daniel I.,Palomo, Valle,Pérez, Concepción,Gil, Carmen,Dans, Pablo D.,Luque, F. Javier,Conde, Santiago,Martínez, Ana
-
experimental part
p. 4042 - 4056
(2011/08/05)
-
- One-pot synthesis of α-formyloxy ketones from enolizable ketones
-
One-pot synthesis of α-formyloxy tones as well as α-acetoxy ketones from enolizable ketones and [hydroxy(tosyloxy) iodo] benzene (HTIB)/polymer supported [hydroxy(tosyloxy) iodo] benzene (PSHTIB) in N,N-dimethylformamide (DMF)/N, N-dimethylacetamide (DMA)
- Kumar, Sunil,Kumar, Ashok,Gupta, Rakesh K.,Kumar, Devinder
-
p. 338 - 345
(2008/04/01)
-
- An efficient method for the α-acetoxylation of ketones
-
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
-
p. 1165 - 1168
(2008/02/03)
-
- Synthesis and biological evaluation of quinoline salicylic acids as P-selectin antagonists
-
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
-
-
- Iodobenzene-catalyzed α-acetoxylation of ketones. In situ generation of hypervalent (diacyloxyiodo)benzenes using m-chloroperbenzoic acid
-
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
-
p. 12244 - 12245
(2007/10/03)
-
- Chemoenzymatic synthesis of enantiomerically pure 1,2-diols employing immobilized lipase in the ionic liquid [bmim]PF6
-
Significantly enhanced enantioselectivity in the enzymatic kinetic resolution of 1,2-diols employing immobilized lipase from Pseudomonas cepacia (PS-C, 'Amano') results from the use of the ionic liquid [bmim]PF6 as reaction medium.
- Kamal, Ahmed,Chouhan, Gagan
-
p. 8801 - 8805
(2007/10/03)
-
- Ionic liquids as reaction media for esterification of carboxylate sodium salts with alkyl halides
-
Ionic liquids based on 1,3-dialkylimidazolinium methanesulfonate have been used as effective reusable reaction media in the esterification of several carboxylate sodium salts with different alkyl halides. Products are easily isolated by extraction with ether, and the protocol is mild and green, compared to the existing methods based on toxic solvents. Proper 'design' of the ionic liquid allows us to obtain esters always in quantitative yields.
- Brinchi,Germani,Savelli
-
p. 2027 - 2029
(2007/10/03)
-
- Chemoenzymatic synthesis of enantiomerically pure terminal 1,2-diols
-
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
-
p. 3861 - 3866
(2007/10/03)
-
- Chemo-enzymatic preparation of hydroxymethyl ketones
-
A series of hydroxymethyl ketones 4a-g were obtained from the corresponding halogenomethyl ketones 2a-g via their transformation into acetoxymethyl ketones 3a-g by 18-crown-6 catalysed substitution with NaOAc followed by Novozyme 435 catalysed ethanolysis. This convenient chemo-enzymatic route provides a mild, heavy-metal-free alternative to the direct α-hydroxylations of methyl ketones 1a-g.
- Paizs, Csaba,Tosa, Monica,Majdik, Cornelia,Bodai, Viktoria,Novak, Lajos,Irimie, Florin-Dan,Poppe, Laszlo
-
p. 2400 - 2402
(2007/10/03)
-
- Biosynthesis of 4-methylcoumarin
-
Tracer experiments prove that ethyl acetoacetate is a specific precursor of 4-methylcoumarin in Trigonella foenumgraecum.
- Raj,Kapil,Bhaumik,Mahesh
-
p. 759 - 762
(2007/10/03)
-
- Baker's yeast-mediated reduction of α-hydroxy ketones and derivatives: The steric course of the biotransformation
-
The results from the baker's yeast-mediated reduction of the acetates 3a- d and the methyl ethers 5a-d were compared with the same biotransformation which converts the α-hydroxy ketones 1a-d into the (R)-diols 2a-d (90- 98%ee); the acetates 3a-d afford the (S)-monoacetates 4a-d (72-94% ee) and the methyl ethers 5a-d are reduced to the (R)-monoethers 6a-d (64-76% ee).
- Ferraboschi, Patrizia,Grisenti, Paride,Manzocchi, Ada,Santaniello, Enzo
-
p. 10539 - 10548
(2007/10/02)
-
- TRIS(3,6-DIOXAHEPTYL)AMINE AS A PHASE-TRANSFER CATALYST IN PHENACYL ESTER SYNTHESIS
-
Tris(3,6-dioxaheptyl)amine (TDA-1) may be substituted for toxic crown ethers in the phase-transfer catalyzed synthesis of phenacyl esters from weakly nucleophilic potassium carboxylates and α,p-dibromoacetophenone in acetonitrile.
- Bartsch, Richard A.,Phillips, John B.
-
p. 1777 - 1780
(2007/10/02)
-
- SYNTHESIS OF PHENACYL ESTERS VIA AN ORGANOTIN ROUTE
-
A facile and convenient method for the synthesis of phenacyl esters using organostannyl carboxylates and phenacyl bromides in the presence of quaternary ammonium salts is reported.In the absence of the quaternary ammonium salt the yields are poor and the
- Vijayaraghavan, S. T.,Balasubramanian, T. R.
-
-
- INVESTIGATIONS ON THE BIOSYNTHESIS OF FLEXIRUBIN - THE ORIGIN OF BENZENE RING B AND ITS SUBSTITUENTS
-
Experiments on the biosynthesis of flexirubin (1) from the gliding bacterium Flexibacter elegans using 14C- and 13C- labelled acetate as well as investigations on the metabolites of a blocked mutant showed, that (a) all carbon atoms of ring B are derived
- Achenbach, Hans,Boettger-Vetter, Angelika,Hunkler, Dieter,Fautz, Erich,Reichenbach, Hans
-
p. 175 - 186
(2007/10/02)
-