- Iridium Complexes as Efficient Catalysts for Construction of α-Substituted Ketones via Hydrogen Borrowing of Alcohols in Water
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Ketones are of great importance in synthesis, biology, and pharmaceuticals. This paper reports an iridium complexes-catalyzed cross-coupling of alcohols via hydrogen borrowing, affording a series of α-alkylated ketones in high yield (86 %–95 %) and chemoselectivities (>99 : 1). This methodology has the advantages of low catalyst loading (0.1 mol%) and environmentally benign water as the solvent. Studies have shown the amount of base has a great impact on chemoselectivities. Meanwhile, deuteration experiments show water plays an important role in accelerating the reduction of the unsaturated ketones intermediates. Remarkably, a gram-scale experiment demonstrates this methodology of iridium-catalyzed cross-coupling of alcohols has potential application in the practical synthesis of α-alkylated ketones.
- Luo, Nianhua,Zhong, Yuhong,Wen, Huiling,Shui, Hongling,Luo, Renshi
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p. 1355 - 1364
(2021/03/03)
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- Rhodium-Catalyzed Deoxygenation and Borylation of Ketones: A Combined Experimental and Theoretical Investigation
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The rhodium-catalyzed deoxygenation and borylation of ketones with B2pin2 have been developed, leading to efficient formation of alkenes, vinylboronates, and vinyldiboronates. These reactions feature mild reaction conditions, a broad substrate scope, and excellent functional-group compatibility. Mechanistic studies support that the ketones initially undergo a Rh-catalyzed deoxygenation to give alkenes via boron enolate intermediates, and the subsequent Rh-catalyzed dehydrogenative borylation of alkenes leads to the formation of vinylboronates and diboration products, which is also supported by density functional theory calculations.
- Tao, Lei,Guo, Xueying,Li, Jie,Li, Ruoling,Lin, Zhenyang,Zhao, Wanxiang
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p. 18118 - 18127
(2020/11/26)
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- Visible Light-Mediated [2 + 2] Cycloaddition Reactions of 1,4-Quinones and Terminal Alkynes
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A single-step synthesis of 4-hydroxy-functionalized bi-aryl and aryl/alkyl ketones via oxidative coupling of terminal alkynes with benzoquinones is reported. Furthermore, with naphthoquinones, owing to the cross-resonance of carbonyl with the aromatic ring, alkene-alkyne cycloaddition is more favored to give four-membered carbocyclic adducts, thereby precluding the requirement of preactivated alkynes.
- Sultan, Shaista,Bhat, Muneer-Ul-Shafi,Rizvi, Masood Ahmad,Shah, Bhahwal Ali
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p. 8948 - 8958
(2019/08/12)
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- Visible Light Copper Photoredox-Catalyzed Aerobic Oxidative Coupling of Phenols and Terminal Alkynes: Regioselective Synthesis of Functionalized Ketones via C C Triple Bond Cleavage
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Direct oxidative coupling of phenols and terminal alkynes was achieved at room temperature by a visible-light-mediated copper-catalyzed photoredox process. This method allows regioselective synthesis of hydroxyl-functionalized aryl and alkyl ketones from simple phenols and phenylacetylene via C C triple bond cleavage. 47 examples were presented. From a synthetic perspective, this protocol offers an efficient synthetic route for the preparation of pharmaceutical drugs, such as pitofenone and fenofibrate.
- Sagadevan, Arunachalam,Charpe, Vaibhav Pramod,Ragupathi, Ayyakkannu,Hwang, Kuo Chu
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supporting information
p. 2896 - 2899
(2017/03/11)
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- THIOSEMICARBAZONES INHIBITORS OF LYSOPHOSPHATIDIC ACID ACYLTRANSFERASE AND USES THEREOF
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Lysophosphatidic acid acyltransferase-beta (LPAAT-β) catalyzes the production of phosphatidic acid (PA) from lysophosphatidic acid (LPA). The lipid cofactor PA contributes to the activation of c-Raf, BRAF, mTOR and PKC-ζ. LPAAT-β expression is a prognostic factor in gynecologic malignancies and is being investigated as a therapeutic target in a variety of tumor types. A class of thiosemicarbazones was identified as inhibitors of LPAAT-β from a screen of a library of small molecules. A focused library of thiosemicarbazones derivatives was prepared and led to the development of compounds which potently inhibit LPAAT-β and inhibit the growth of MiaPaCa2 human pancreatic cancer cells.
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Page/Page column 16
(2015/11/17)
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- Synthesis, biochemical evaluation and rationalisation of a series of 3,5- dibromo derivatives of 4-hydroxyphenyl ketone-based compounds as probes of the active site of type 3 of 17β-hydroxysteroid dehydrogenase (17β-hsd3) and the role of hydrogen bonding interaction in the inhibition of 17β-HSD3
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We report the synthesis, evaluation and rationalisation of the inhibitory activity of a series of 3,5-dibromo derivatives of 4-hydroxyphenyl ketone as probes of the active site of the type 3 of 17β-hydroxysteroid dehydrogenase (17β-HSD3). The results support the important role of hydrogen bonding interaction in the inhibition of 17β-HSD3.
- Olusanjo, Moniola S.,Mashru, Shreena N.,Cartledge, Timothy,Ahmed, Sabbir
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scheme or table
p. 604 - 610
(2012/08/28)
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- Comparisons of O-acylation and Friedel-Crafts acylation of phenols and acyl chlorides and Fries rearrangement of phenyl esters in trifluoromethanesulfonic acid: Effective synthesis of optically active homotyrosines
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Reactions involving phenol derivatives and acyl chlorides have to be controlled for competitive O-acylations and C-acylations (Friedel-Crafts acylations and Fries rearrangements) in acidic condition. The extent for these reactions in trifluoromethanesulfonic acid (TfOH), which is used as catalyst and solvent, is examined. Although diluted TfOH was needed for effective O-acylation, concentrated TfOH was required for effective C-acylations in mild condition. These results have been applied to the novel synthesis of homotyrosine derivatives. Both Fries rearrangement of N-TFA-Asp(OBn)-OMe and Friedel-Crafts acylation of phenol with N-TFA-Asp(Cl)-OMe in TfOH afforded the homotyrosine skeleton, followed by reduction and deprotection afforded homotyrosines maintaining stereochemistry of Asp as an optically pure form.
- Murashige, Ryo,Hayashi, Yuka,Ohmori, Syo,Torii, Ayuko,Aizu, Yoko,Muto, Yasuyuki,Murai, Yuta,Oda, Yuji,Hashimoto, Makoto
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experimental part
p. 641 - 649
(2011/03/19)
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- Synthesis and biochemical evaluation of a series of trifluoromethanesulfonate derivatives of 4 hydroxyphenyl ketones - Probes of the active site of type 1 and 3 of the 17β-hydroxysteroid dehydrogenase family of enzymes
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In an effort to aid the design of 'dual-inhibitors' of types 1 and 3 of the 17β-hydroxysteroid dehydrogenase (17β-HSD), we report the synthesis, biochemical evaluation and rationalisation of the inhibitory activity of trifluoromethanesulfonate derivatives of 4-hydroxyphenyl ketone-based compounds which were found to be weak inhibitors of types 1 and 3.
- Olusanjo, Moniola S.,Cartledge, Timothy,Shah, Kruti,Ahmed, Sabbir
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p. 253 - 259
(2013/01/10)
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- Synthesis, biochemical evaluation and rationalisation of the inhibitory activity of a series of 4-hydroxyphenyl ketones as potential inhibitors of 17β-hydroxysteroid dehydrogenase type 3 (17β-HSD3)
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We report the preliminary results of the synthesis and biochemical evaluation of a number of 4-hydroxyphenyl ketones as inhibitors of the isozyme of the enzyme 17β-hydroxysteroid dehydrogenase (17β-HSD) responsible for the conversion of androstenedione (AD) to testosterone (T), more specifically type 3 (17β-HSD3). The results of our study suggest that we have synthesised compounds which are, in general, potent inhibitors of 17β-HSD3, in particular, we discovered that 1-(4-hydroxy-phenyl)-nonan-1-one (8) was the most potent (IC50 = 2.86 ± 0.03 μM). We have therefore provided good lead compounds in the synthesis of novel non-steroidal inhibitors of 17β-HSD3.
- Lota, Rupinder K.,Dhanani, Sachin,Owen, Caroline P.,Ahmed, Sabbir
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p. 4519 - 4522
(2007/10/03)
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- Pd-catalyzed carbonylative cross-coupling reactions by triorganoindiums: Highly efficient transfer of organic groups attached to indium under atmospheric pressure
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(Matrix presented) A highly atom-efficient synthetic method of unsymmetrical ketones was developed by using trialkyl- and triarylindiums, which could be employed as effective cross-coupling partners in Pd-catalyzed carbonylative cross-coupling reactions with a variety of organic electrophiles. The present method produced unsymmetrical ketones and 1,4-diacylbenzenes in good yields with highly efficient transfer of almost all the organic groups attached to the indium under atmospheric pressure of CO gas in THF at 66°C.
- Lee, Phil Ho,Lee, Sung Wook,Lee, Kooyeon
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p. 1103 - 1106
(2007/10/03)
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- Novel inhibitors of the enzyme estrone sulfatase (ES)
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We report the initial results of our study into a series of simple 4-sulfamated phenyl alkyl ketones as potential inhibitors of the enzyme estrone sulfatase. The results of the study show that these compounds are potent inhibitors, possessing greater inhibitory activity than COUMATE, but weaker activity than EMATE. Furthermore, the compounds are observed to be irreversible inhibitors.
- Ahmed, Sabbir,James, Karen,Owen, Caroline P,Patel, Chirag K,Patel, Mijal
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p. 841 - 844
(2007/10/03)
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- Hydrophobicity, a physicochemical factor in the inhibition of the enzyme estrone sulfatase (ES)
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We report the initial structure-activity relationship study (SAR) (in particular log P) of a series of compounds based upon 4-sulfamated phenyl ketones as potent inhibitors of the enzyme estrone sulfatase (ES). The results of the study show that these compounds are irreversible inhibitors of ES and that they are more potent than COUMATE, but weaker than EMATE. Analysis of the SAR data shows a strong correlation between IC50 and log P but also supports our previous study, which suggests a very strong relationship between pKa and IC50.
- Ahmed, Sabbir,James, Karen,Owen, Caroline P.,Patel, Chirag K.,Patel, Mijal
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p. 2525 - 2528
(2007/10/03)
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- Study of bonding characteristics of some new metal complexes of salicylaldoxime (SALO) and its derivatives by far infrared and UV spectroscopy
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New metal chelates of copper, lead and zinc with salicylaldoxime (SALO) and its derivatives have been prepared. The chelates have been characterized by elemental analysis, atomic absorption, infrared and UV spectroscopy. SALO behaves as a bidentate ligand forming neutral metal chelates through the phenolic oxygen and the oxime nitrogen. The M-O stretching frequencies for the transition metals show good agreement with the Irving-William's stability order Cu > Zn > Pb. Similar trend is seen for the M-N stretching frequencies in IR and the shift in transitions from UV spectral data for the metal chelates.
- Ramesh,Umasundari,Das, Kalyan K.
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p. 285 - 297
(2007/10/03)
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- Cytotoxicity and antiestrogenicity of a novel series of basic diphenylethylenes
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On the premise that it is necessary to develop antiestrogens with a higher cytotoxic component in order to reduce the risks of the development of heterogeneous malignant cell populations in breast cancer, we studied a novel series of basic diphenylethylenes, for the most part devoid of estrogenic activity, with low antiestrogenicity but much enhanced cytotoxicity compared to the reference drug tamoxifen. The main structural features associated with cytotoxicity were E isomery, substituents of five to eight carbons on the ethylene bond, and dibasicity.
- Gilbert, Jacques,Fuentes, Maryse,Ojasoo, Tiiu,Doré, Jean-Christophe,Pons, Michel
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p. 1104 - 1111
(2007/10/03)
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- β-Cyclodextrin Effects on the Photo-Fries Rearrangement of Aromatic Alkyl Esters
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The photolysis of phenyl propionate (1a) and phenyl valerate (1b) in water and in solutions containing β-cyclodextrin (CD) leads to the corresponding p-hydroxyphenyl alkyl ketone 2, o-hydroxyphenyl alkyl ketone 3, and phenol 4.When the reactions are carried out in the presence of oxygen there is a decrease in the total amount of rearrangement products, but the inhibition is less marked in the presence of CD.The / ratio for 1b increases when CD concentration changes from 0 to 10 mM.These changes are due to the increase in the quantum yield for the formation of 3 and a decrease in the quantum yield for 2 in the solutions containing CD.The / ratio for 1a decreases in the presence of CD although both quantum yields increase with CD concentrations.Under the conditions used in this study, the substrate reacted in the bulk solution and in the cavity of CD.The quantum yields for the formation of 3 and 4, ΦCD3 and ΦCD4, are higher for the included substrate than the corresponding values for the free substrate while ΦCD2 is higher than Φw2 for 1a but lower for 1b.This effect is attributed to the different orientation of the substrates in the cavity of CD.Besides, ΦCD4 also increases due to the availability of hydrogens bonded to secondary carbons in the cavity of the cyclodextrin.
- Veglia, Alicia V.,Rossi, Rita H. de
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p. 4941 - 4944
(2007/10/02)
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- Aliphatic Liquid Crystals, 2. Some Nematic Derivatives of all-trans-Perhydrophenanthrene
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A stereoselective synthesis of the all-trans-7-alkylperhydro-2-phenanthrenols 15a-f in 11 steps and 28 liquid crystalline esters 16 of 15a-f are described, additionally some further derivatives of 7-alkylperhydro-2-phenanthrenol.An X-ray structure analysis of ester 16ec is reported.
- Sucrow, Wolfgang,Minas, Hermann,Stegemeyer, Horst,Geschwinder, Peter,Murawski, Hans-Ruediger,Krueger, Carl
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p. 3332 - 3349
(2007/10/02)
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- RECHERCHES SUR LES SUBSTANCES MESOGENES-VIII; PREPARATION ET PROPERTIES MESOMORPHES DE SERIES ISOMETRIQUES
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The synthesis and the mesomorphic properties of various series of isometric mesogenic compounds are described.It is confirmed that isometric mesogenic molecules may be nematogenic and/or smectogenic according to the position of the polar rigid core.
- Malthete, Jacques,Canceill, Josette,Gabard, Jacqueline,Jacques, Jean
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p. 2815 - 2821
(2007/10/02)
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