- Second Generation Total Synthesis of (–)-Preussochromone D
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An improved enantioselective synthesis of the natural product (–)-preussochromone D (3) and first insights into a possible route to the trans-preussochromones E and F are described. Starting from commercially available 5-hydroxy-4H-chromen-4-one, two ster
- Beller, Marc Paul,Kerste, Eric,Koert, Ulrich
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- Air-stable binuclear Titanium(IV) salophen perfluorobutanesulfonate with zinc power catalytic system and its application to C–S and C–Se bond formation
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An air-stable μ-oxo-bridged binuclear Lewis acid of titanium(IV) salophen perfluorobutanesulfonate [{Ti(salophen)H2O}2O][OSO2C4F9]2 (1) was successfully synthesized by the reaction of TiIV(salophen)Cl2 with AgOSO2C4F9 and characterized by techniques such as IR, NMR and HRMS. This complex was stable open to air over a year, and exhibited good thermal stability and high solubility in polar organic solvents. The complex also had relatively strong acidity with a strength of 0.8 Ho ≤ 3.3, and showed high catalytic efficiency towards various C–S and C–Se bond formations in the presence of zinc power. This catalytic system affords a mild and efficient approach to synthesis of thio- and selenoesters, α-arylthio- and seleno-carbonyl compounds, and thio- and selenoethers.
- Wang, Lingxiao,Qiao, Jie,Wei, Jiancong,Liang, Zhiwu,Xu, Xinhua,Li, Ningbo
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- Preparation method and application of novel ionic binuclear Schiff base titanium complex
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The invention provides a preparation method of a novel ionic binuclear Schiff base titanium complex and a synthetic method of applying the novel ionic binuclear Schiff base titanium complex to catalyze zinc powder and reduce disulfide or selenide to prepare sulfo(seleno) ester and dissymmetric sulfoether(selenide). The complex is a cationic binuclear Schiff base titanium complex, wherein titaniumatoms are bridged by oxygen atoms and are coordinated with a Schiff base ligand and a hydrone, and an ionic bond is formed by a cation part and an anion part of whole Schiff base titanium. The ionic binuclear Schiff base titanium complex is used as a catalyst, the zinc powder is used as a reducer, the disulfide(selenide) can be reduced and fractured, and the disulfide(selenide) can further and respectively react with anhydride, an alpha-bromo carbonyl compound and bromoalkane to prepare the sulfo(seleno) ester and the dissymmetric sulfoether(selenide). According to the preparation method provided by the invention, the defects that traditional lewis acid halide is deliquescent, an absolute solvent is used, conditions are strict and the like are overcome; an effective path for reducing the disulfide or selenide to prepare the sulfo(seleno) ester and the dissymmetric sulfoether(selenide) is provided, and the preparation method has the advantages of high yield, simpleness in operation andthe like.
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Paragraph 0073; 0074
(2018/04/03)
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- Fe-Mediated S-S Bond Cleavage and Its Application in the Synthesis of α-Arylthio Carbonyl Compounds
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In the presence of iron dust, diaryl disulfides react with α-bromo carbonyl compounds to obtain α-arylthio carbonyl compounds in good yield at 90 °C under an N2 atmosphere, using commercial dimethylformamide (DMF) as solvent. The possible reaction mechanism is that the disulfide is reduced by iron dust to give ArSFeSAr and then reacted with α-bromo carbonyl compounds to give product α-arylthio carbonyl compounds and FeBr2.
- He, Yun-Hua,Li, Ning-Bo,Chen, Jin-Yang,Qiu, Ren-Hua,Wang, Xie,Xu, Xin-Hua
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p. 1817 - 1822
(2015/08/06)
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- Synthesis and absolute configuration of novel N,O-psiconucleosides using (R)-N-phenylpantolactam as a resolution agent
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(Chemical Equation Presented) A series of novel N,O-psiconucleosides has been prepared in both enantiomeric forms by resolution of an advanced racemic synthetic intermediate using (R)-N-phenylpantolactam as a chiral resolution agent. The absolute configur
- Camps, Pelayo,Gomez, Tania,Munoz-Torrero, Diego,Rull, Jordi,Sanchez, Laura,Boschi, Francesca,Comes-Franchini, Mauro,Ricci, Alfredo,Calvet, Teresa,Font-Bardia, Merce,De Clercq, Erik,Naesens, Lieve
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p. 6657 - 6665
(2008/12/23)
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- Trichosporon beigelli esterase (TBE): A versatile esterase for the resolution of economically important racemates
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A hydrolase producing strain Trichosporon beigelli esterase (TBE) isolated from local cottage cheese in its native form has displayed versatility and high efficacy in the kinetic resolution of a wide range of economically important substrates, which include racemic secondary alcohols, such as 1-(6-methoxy-2-naphthyl)ethanol (E ~ 316), 1-(3,4-methylenedioxyphenyl) ethanol and pentanol (E ~ 180 and 156 resp.), and alkyl esters of carboxylic acids such as ibuprofen (E ~ 340), 2-(benzylthio)propanoic acid (E ~ 1000). In other substrates such as in the primary alcohol 2-(6-methoxy-2- naphthyl)propan-1-ol and carboxylic acids such as 2-(5-bromo-6-methoxy-2- naphthyl)propanoic acid, 2-(2-naphthyloxy)propanoic acid, and substituted 2-thiopropanoic acids, it displayed moderate to low selectivity. Commercial lipases such as CCL, PPL, and PSL were also used in the resolution of the substrates for comparative studies.
- Koul, Surrinder,Koul, Jawahir Lal,Singh, Budh,Kapoor, Munish,Parshad, Rajinder,Manhas, Kuldeep S.,Taneja, Subhash C.,Qazi, Ghulam N.
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p. 2575 - 2591
(2007/10/03)
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- Inhibitors of glycogen synthase kinase 3
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New pyrimidine or pyridine based compounds, compositions and methods of inhibiting the activity of glycogen synthase kinase (GSK3) in vitro and of treatment of GSK3 mediated disorders in vivo are provided. The methods, compounds and compositions of the invention may be employed alone, or in combination with other pharmacologically active agents in the treatment of disorders mediated by GSK3 activity, such as diabetes, Alzheimer's disease and other neurodegenerative disorders, obesity, atherosclerotic cardiovascular disease, essential hypertension, polycystic ovary syndrome, syndrome X, ischemia, traumatic brain injury, bipolar disorder, immunodeficiency or cancer.
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- Facile and efficient sulfenylation method using quinone mono-O,S-acetals under mild conditions
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A novel sulfenylation method induced by aromatization of quinone mono-O,S-acetals is described. These sulfenylation reagents readily react with silyl enolethers or electron rich aromatic compounds to give sulfenylation products under mild conditions. In particular, O,S-acetal 2j, which possesses a pentafluorophenylthio function, is the most effective reagent from the standpoint of the adaptability for various substrates.
- Matsugi,Murata,Gotanda,Nambu,Anilkumar,Matsumoto,Kita
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p. 2434 - 2441
(2007/10/03)
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- A novel efficient sulfenylation method using quinone mono-O,S-acetals under mild conditions
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A novel method for sulfenylation induced by aromatization of quinone mono-O,S-acetals is described.
- Matsugi, Masato,Gotanda, Kentoku,Murata, Kenji,Kita, Yasuyuki
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p. 1387 - 1388
(2007/10/03)
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- Organic Synthesis with α-Chloro Sulphides. Preparation of Aromatic γ-Lactones from Phenols and α-Chloro Sulphide Carboxylates
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Lewis acid-catalysed alkylation of para-substituted phenols using α-chloro sulphides as electrophiles yields sulphenylated γ-lactones which can be desulphurised with zinc in acetic acid or Raney nickel.This synthesis has been applied to p-cresol, 2-naphthol, and two phenolic dihydrocinnamates.Alkylation of 1,4-dimethoxybenzene yields homogentisic acid dimethyl ether after desulphurisation and hydrolysis.
- Kennedy, Michael,McKervey, M. Anthony,Maguire, Anita R.,Naughton, Sean
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p. 1041 - 1045
(2007/10/02)
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- CHIMIE des FRAGRANCES. PARTIE I : NOUVELLE STRATEGIE de SYNTHESE de α-(2-OXOCYCLOHEXYL)-ACRYLATES de METHYLE
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Highly stereoselective tandem 1,4-addition-functionalisation reactions have been performed on various cyclohexenones using methyl α-sulphinylacrylate as an efficient enolate trapping reagent.
- Leyendecker, Francois,Comte, Marie-Therese
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p. 1413 - 1422
(2007/10/02)
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- NEW ACETYLENIC MICHAEL RECEPTOR EQUIVALENTS. PART I : SYNTHESIS OF α-SULFENYL - AND α-SULFINYL ACRYLIC DERIVATIVES.
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The synthesis of α-thioarylated β-unsubstituted acrilic derivatives is reported.
- Leyendecker, Francois,Comte, Marie-Therese
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p. 5031 - 5034
(2007/10/02)
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