- C-S coupling with nitro group as leaving group via simple inorganic salt catalysis
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An efficient and practical synthetic protocol to synthesize nonsymmetrical aryl thioethers by nucleophilic aromatic substitution (SNAr) reaction of nitroarenes by thiols with potassium phosphate as the catalyst is described. Various moderate to strong electron-withdrawing functional groups are tolerated by the system to provide thioethers in a good to excellent yields. We also showed that the present method allows access to 3 drug examples in a short reaction time. Finally, mechanistic studies suggest that the reaction may form the classic Meisenheimer complex through a two-step addition-elimination mechanism.
- Xuan, Maojie,Lu, Chunlei,Lin, Bo-Lin
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supporting information
(2019/08/26)
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- 3-PHOSPHOGLYCERATE DEHYDROGENASE INHIBITORS AND USES THEREOF
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The present invention provides compounds, compositions thereof, and methods of using the same.
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Paragraph 00308
(2017/10/06)
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- C-H Alkenylation of Heteroarenes: Mechanism, Rate, and Selectivity Changes Enabled by Thioether Ligands
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Thioether ancillary ligands have been identified that can greatly accelerate the C-H alkenylation of O-, S-, and N-heteroarenes. Kinetic data suggest thioether-Pd-catalyzed reactions can be as much as 800× faster than classic ligandless systems. Furthermore, mechanistic studies revealed C-H bond cleavage as the turnover-limiting step, and that rate acceleration upon thioether coordination is correlated to a change from a neutral to a cationic pathway for this key step. The formation of a cationic, low-coordinate catalytic intermediate in these reactions may also account for unusual catalyst-controlled site selectivity wherein C-H alkenylation of five-atom heteroarenes can occur under electronic control with thioether ligands even when this necessarily involves reaction at a more hindered C-H bond. The thioether effect also enables short reaction times under mild conditions for many O-, S-, and N-heteroarenes (55 examples), including examples of late-stage drug derivatization.
- Gorsline, Bradley J.,Wang, Long,Ren, Peng,Carrow, Brad P.
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supporting information
p. 9605 - 9614
(2017/07/24)
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- Copper nanoparticles supported on polyaniline-functionalized multiwall carbon nanotubes: An efficient and recyclable catalyst for synthesis of unsymmetric sulfides using potassium ethyl xanthogenate in water
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A new and powerful polyaniline-functionalized carbon nanotube-supported copper(II) nanoparticle catalyst was successfully prepared and evaluated as a heterogeneous catalyst for the one-pot synthesis of unsymmetric thioethers by coupling of aryl, alkyl and benzyl halides using potassium ethyl xanthogenate as source of sulfur in water. All of these reactions gave the desired products in good to excellent yields. The catalyst is available, air-stable and can be reused several times without significant loss in its catalytic activity.
- Hajipour, Abdol R.,Jajarmi, Saeideh,Khorsandi, Zahra
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- SULFOXIMINE-SUBSTITUTED ANILINOPYRIMIDINE DERIVATIVES AS CDK INHIBITORS, THE PRODUCTION THEREOF, AND USE AS MEDICINE
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The invention relates to sulfoximine-substituted anilino-pyrimidine derivatives of formula (I). methods of production thereof, and use thereof as medication for the treatment of various diseases.
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Page/Page column 16
(2011/12/13)
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- A kinetic investigation, supported by theoretical calculations, of steric and ring strain effects on the oxidation of sulfides and sulfoxides by dimethyldioxirane in acetone
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The oxidations of alkyl 4-nitrophenyl, and dialkyl, sulfides and sulfoxides by dimethyldioxirane in acetone occur by concerted mechanisms but the sulfides respond differently from the sulfoxides to variation in the alkyl group. The reactions of the sulfides are inhibited by the steric effects of alkyl groups and these predominate over their inductive effects. By contrast, the reactions of these limited sets of sulfoxides are insensitive to alkyl steric effects but there is an indication of steric acceleration when a broader set of sulfoxides is considered. This behaviour is rationalised in terms of the differences in dipolar charge and its solvation between the ground state and transition state for the two types of substrate. The oxidations of cyclic sulfides and sulfoxides also exhibit contrasting behaviour. The reactivity of the sulfides is insensitive to ring strain but is explicable in frontier orbital terms whereas that of the sulfoxides is partly dependent upon the change in ring strain between reactant and product on oxidation, a difference rationalised in terms of the relative positions of the transition states in the reaction coordinates of the two oxidations. The reactivity of 4-, 5- and 6-membered cyclic sulfoxides is also dependent on a ring-size related property of the transition state. Calculations at the B3-LYP/6-31G* level of density functional theory on both ground states and transition states, including simulation of solvation by acetone, strongly support the mechanistic conclusions reached in this and earlier work.
- Hanson, Peter,Hendrickx, Ramon A. A. J.,Lindsay Smith, John R.
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supporting information; experimental part
p. 65 - 84
(2011/01/07)
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- Synthesis of aryl sulfides by decarboxylative C-S cross-couplings
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A study was conducted to demonstrate the transition-metal-catalyzed synthesis of aryl sulfides by decarboxylative C-S cross-couplings. Coupling reaction of 2-nitrobenzoic acid with 1-octanethiol were carried in the presence of different combinations of tr
- Duan, Zhongyu,Ranjit, Sadananda,Zhang, Pengfei,Liu, Xiaogang
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supporting information; experimental part
p. 3666 - 3669
(2009/12/07)
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- Sulfite-promoted one-pot synthesis of sulfides by reaction of aryl disulfides with alkyl halides
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A sodium dithionite, sodium thiosulfate and rongalite promoted one-pot synthesis of aryl alkyl sulfides at room temperature has been developed. The reactions of a range of disulfides with alkyl halides proceeded smoothly in the presence of rongalite. Possible reaction pathways are discussed and the effects of these sulfites on disulfides are investigated. The important features of this protocol are metal-free, strong-base-free, and mild reaction conditions, operational simplicity, short reaction times and high yields of products. Georg Thieme Verlag Stuttgart.
- Tang, Ri-Yuan,Zhong, Ping,Lin, Qiu-Lian
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- One-pot synthesis of sulfides by reaction of disulfides with alkyl halides in the presence of sodium dithionite
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Sodium dithionite-promoted synthesis of unsymmetrical diorganyl sulfides by a reaction of diaryl disulfides with alkyl halides at r.t. has been developed. The advantages offered by this method are operational simplicity, a faster reaction, neutral and mild reaction conditions, and moderate to good yields of products.
- Tang, Ri-Yuan,Zhong, Ping,Lin, Qiu-Lian
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p. 167 - 174
(2007/10/03)
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- CsF-Celite, an efficient solid state reagent for the syntheses of thioesters and thioethers
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Coupling reactions of a number of aliphatic, aromatic, and heterocyclic compounds bearing an acidic hydrogen atom attached to sulfur, with alkyl, acyl, benzyl, or benzoyl halides in acetonitrile with cesium fluoride-Celite are described. This procedure is convenient, efficient, and practical for the preparation of thioethers and thioesters. Springer-Verlag 2005.
- Shah, Syed T. A.,Khan, Khalid M.,Hussain, Hidayat,Hayat, Safdar,Voelter, Wolfgang
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p. 1583 - 1589
(2007/10/03)
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- Synthesis and in vitro antifungal activity of 4-substituted phenylguanidinium salts
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A series of 4-substituted phenylguanidinium derivatives was synthesized and its antimicrobial activity was evaluated in vitro against eight potentially pathogenic strains of fungi.
- Braunerova, Gabriela,Buchta, Vladimir,Silva, Luis,Kunes, Jiri,Palat Jr., Karel
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p. 443 - 450
(2007/10/03)
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- An alternative approach towards the syntheses of thioethers and thioesters using CsF-Celite in acetonitrile
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It has been found that syntheses of thioethers and thioesters of aliphatic, aromatic and heterocyclic compounds, bearing thiol groups, can be accomplished with alkyl, acyl, benzyl or benzoyl halides in acetonitrile and cesium fluoride-Celite. In this manner, compounds like ethanethiol, 1-pentanethiol, thiophenol, 4-methoxythiophenol, 4-nitrothiophenol, and 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, and 2-mercapto-2-thiazoline can be successfully alkylated, acylated, benzylated or benzoylated. This procedure is convenient, efficient and practical for the preparation of thioethers and thioesters.
- Shah, Syed Tasadaque Ali,Khan, Khalid Mohammed,Martinez Heinrich, Angelica,Voelter, Wolfgang
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p. 8281 - 8283
(2007/10/03)
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- 1,2-Diarylpyrroles as potent and selective inhibitors of cyclooxygenase- 2
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Series of 1,2-diarylpyrroles has been synthesized and found to contain very potent and selective inhibitors of the human cyclooxygenase-2 (COX-2) enzyme. The paper describes short and practical syntheses of the target molecules utilizing the Paal-Knorr reaction. Electrophilic substitution on 1 proceeds in a regioselective fashion, and the method was used to generate a number of tetrasubstituted pyrroles. Detailed SAR on the series has been studied by modifications of the aryl rings and the substituents in the pyrrole ring. Diarylpyrrole 1 is a very potent (COX-2, IC50 = 60 nm) and selective (COX-1/COX-2 = > 1700) inhibitor whereas the isomeric 2 is completely inactive against COX-2. Modifications of the substituents on the fluorophenyl ring in 1 yields very potent inhibitors of COX-2 (IC50 = 40- 80 nm) with excellent selectivity(1200 to >2500) vs COX-1, Analog 20 containing a sulfonamide group is an excellent inhibitor of COX-2 with an IC50 of 14 nm. Tetrasubstituted pyrroles containing groups such as COCF3, SO2CF3, or CH2OAr at position 3 in the pyrrole ring give excellent inhibitors (COX-2, IC50 = 30-120 nm). In vivo testing in the carrageenan- induced paw edema model in the rat establishes that the 1,2-diarylpyrroles are orally active antiinflammatory agents. Compound 3 is the most potent inhibitor of edema with an ED50 of 4.7 mpk.
- Khanna, Ish K.,Weier, Richard M.,Yu, Yi,Collins, Paul W.,Miyashiro, Julie M.,Koboldt, Carol M.,Veenhuizen, Amy W.,Currie, Jerry L.,Seibert, Karen,Isakson, Peter C.
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p. 1619 - 1633
(2007/10/03)
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- A Study of the Regioselectivity of the Radical Addition of "RSAr" Derived from the Photolysis of tert-Homoallyl and tert-Alkyl 4-Nitrobenzenesulfenates to Substituted Allenes and Alkenes
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The regioselectivity of the free radical addition of "RSAr" derived from the photolysis of tert-homoallyl and tert-alkyl 4-nitrobenzenesulfenates, followed by β-scission of the alkoxy radicals to produce the allyl or alkyl radicals R., to 1,1- and 1,3-dimethylallene and acrylonitrile and methyl acrylate has been determined.The regioselectivity of addition of "RSAr" to 1,1- and 1,3-dimethylallene occurs by the addition of the arylthiyl radical to the center carbon atom of the allene chromophore, whereas the regioselectivity of the addition to acrylonitrile and methyl acrylate varies with the nature of the R..The results are interpreted in terms of the relative reactivities of the ? systems toward radical addition and the relative rates of β-scission of the intermediate alkoxy radicals versus the rates of addition of the 4-nitrobenzenethiyl radical and R. to the ? systems.
- Pasto, Daniel J.,Cottard, Francois
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p. 4642 - 4646
(2007/10/02)
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- Photooxidation of alkyl 4-nitrophenyl sulfides and sulfoxides. Observation of oxidative C-S bond cleavage and rearrangement reactions
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Alkyl 4-nitrophenyl sulfides and sulfoxides undergo a self-photoinduced, singlet oxygen oxidation to produce a variety of products, including sulfonates and carbonyl compounds formed by the oxidative cleavage of the C-S bond of the sulfides and sulfoxides. Structural rearrangements are observed in the resulting carbonyl compounds formed in the oxidative cleavage of the C-S bond in the tert-amyl and 2-phenylethyl sulfides. An overall mechanism is proposed which involves the formation of peroxysulfoxides and peroxysulfones which undergo heterolytic C-S bond cleavage to form ion pairs which recombine to form persulfenates or persulfinates which then undergo photo- and/or thermallyinduced homolytic O-O bond cleavage to form alkoxy and sulfinyl or sulfonyl radicals. The alkoxy radicals undergo β-scission, disproportionation, or recombination with the sulfonyl radical to form the observed products. These C-S oxidative cleavage reactions have only been rarely observed in the earlier studies on the singlet oxygen oxidation studies of dialkyl sulfides, and are attributed, in part, to the presence of the 4-nitro group on the aromatic ring which greatly affects the susceptibility of the sulfur atom of the sulfides and sulfoxides toward nucleophilic attack, and on the reactivity of the peroxysulfoxides and peroxysulfones toward heterolytic cleavage of the O-S bond.
- Pasto, Daniel J.,Cottard, Fran?ois,Jumelle, Laurent
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p. 8978 - 8984
(2007/10/02)
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- Photolysis of Alkyl 4-Nitrobenzenesulfenates. A New and Versatile Method for the Generation of Free Radicals
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The irradiation of alkyl 4-nitrobenzenesulfenates with >300-nm wavelength light in benzene solution results in the homolytic cleavage of the O-S bond.The tertiary alkoxy radicals thus formed undergo β scission to produce carbon-centered free radicals in e
- Pasto, Daniel J.,L'Hermine, Gael
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p. 5815 - 5816
(2007/10/02)
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- Relative Nucleophilicities of Aryldisulphide and Thiolate Ions in Dimethylacetamide Estimated from their Reaction Rates with Alkyl Halides
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The relative rates of nucleophilic substitution (SN2) of alkyl halides by aromatic thiolates ArS- and aryldisulphide ions ArS2- have been studied in dimethylacetamide by UV-visible spectrophotometry for Ar = 4-nitrophenyl (1), 2-nitrophenyl (2), and 8-quinolyl (3).Rate constants are relative to the rate constants for benzenethiolate ions (4), studied as reference.With Ar = (1), the reaction rate for disulphide ions is ten times higher than that for monosulphide ions stabilized by the elevated delocalization of their charge.With Ar = (2) and (3), the reactivity of disulphide ions is higher than that of the corresponding thiolates.Our study is consistent with the uncomplicated introduction of a disulphide bond into various substrates from aryldisulphide ions stabilized in aprotic dipolar media.
- Benaichouche, Meriem,Bosser, Gerard,Paris, Jacky,Plichon, Vincent
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p. 1421 - 1424
(2007/10/02)
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- CONFORMATIONAL AND ELECTRONIC INTERACTION STUDIES OF α-SUBSTITUTED CARBONYL COMPOUNDS. VI. p-SUBSTITUTED α-PHENYLTHIOACETONES.
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The analysis of the νCO bands in the I.R. spectrum of p-substituted α-phenylthioacetones indicates a cis/gauche rotational isomerism.The slight solvent effect on the αc αg ratios on going from a non polar solvent to a polar one , for the title compounds, as well as the minute sensitivity of the νCO (cis) frequencies on going from electron-attracting to electron-donating substituents are interpreted on the grounds of the Field (F) and Inductive effects, which act in opposition in the cis rotamer, practically cancelling each other.The decreasing cis/gauche population ratio on going from electron-attracting to electron-donating substituents suggests the occurance of the hyperconjugative interaction in the gauche rotamers of the title compounds.The progressive shielding effect on the methylene and carbonyl carbon atoms in the 13C NMR spectra, on going from electron-donating to electron-attracting substituents is ascribed at least in part, to the "Reverse Polar Effect".Keywords: Conformational studies; electronic interaction; Reverse Polar Effect; I.R. spectroscopy; 13C NMR spectroscopy; p-substituted α-phenylthioacetones.
- Olivato, Paulo R.,Guerrero, Sandra A.,Martins, Elizabeth A. L.
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- REACTIONS OF ORGANOMETALLIC COMPOUNDS CATALYZED BY TRANSITION-METAL COMPLEXES. XV. PRODUCTION OF THIOCARBOXYLIC S-ESTERS BY CATALYTIC CARBONYLATION OF ARYL IODIDES AND TRIETHYLTIN THIOLATES
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Carbonylation in the aryl iodide-triethyltin thiolate system, catalyzed by bis(triphenylphosphine) palladium, was studied.In the case of unactivated aryl iodides containing weak electron-withdrawing substituents thiocarboxylic S-esters are formed with satisfactory yields.The reactions of aryl iodides containing strong electron-withdrawing groups lead mainly to the products from cross-coupling, i.e., unsymmetrical sulfides.The mechanism of the catalytic action of the phosphine complex of palladium was investigated.
- Gulevich, Yu. V.,Bumagin, N. A.,Beletskaya, I. P.
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p. 1918 - 1923
(2007/10/02)
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- Diaryl Sulfide Cleavage by Sodium Sulfide in Dipolar Aprotic Solvents
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The interaction of sodium sulfide with diaryl sulfides that possess electron-withdrawing substituents (e. g., cyano or nitro) on the aromatic rings results in cleavage of the thioether and the formation of sodium aryl sulfides in dipolar aprotic solvents.Exchange reactions between these diaryl sulfides and sodium aryl sulfides are also observed in dipolar aprotic solvents.The cleavage and exchange reactions were employed to prepare mixed diaryl or alkyl aryl sulfides from symmetrical diaryl sulfides.
- Evans, Thomas L.,Kinnard, Richard D.
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p. 2496 - 2499
(2007/10/02)
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- Determination of potentially mutagenic and carcinogenic electrophiles in environmental samples
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Direct acting mutagens are common in many types of environmental samples. Most direct acting mutagens are electrophiles. The nucleophile 4-nitrothiophenol reacts readily with electrophilic alkyl halides and epoxides to form thioethers which have absorptio
- Cheh,Carlson
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p. 1001 - 1006
(2007/10/02)
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