- A mild and chemoselective CALB biocatalysed synthesis of sulfoxides exploiting the dual role of AcOEt as solvent and reagent
-
A mild, chemoselective and sustainable biocatalysed synthesis of sulfoxides has been developed exploiting CALB and using AcOEt with a dual role of more environmentally friendly reaction solvent and enzyme substrate. A series of sulfoxides, including the drug omeprazole, have been synthesised in high yields and with excellent E-factors.
- Anselmi, Silvia,Liu, Siyu,Kim, Seong-Heun,Barry, Sarah M.,Moody, Thomas S.,Castagnolo, Daniele
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supporting information
p. 156 - 161
(2021/01/14)
-
- Air-stable binuclear Titanium(IV) salophen perfluorobutanesulfonate with zinc power catalytic system and its application to C–S and C–Se bond formation
-
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
-
-
- Rhodium-catalyzed Sommelet-Hauser type rearrangement of α-diazoimines: Synthesis of functionalized enamides
-
An efficient rhodium catalyzed Sommelet-Hauser type rearrangement of sulfur ylides derived from α-thioesters and N-sulfonyl-1,2,3-triazoles has been successfully accomplished for the synthesis of various functionalized enamides. The developed reaction involves the unprecedented [2,3]-sigmatropic rearrangement of sulfur ylides with the imine motif. Importantly, the method works well with various substituted α-thioesters/-amides/-ketones and substituted N-sulfonyl-1,2,3-triazoles and allows the synthesis of diverse enamide derivatives in good to excellent yields. The reaction was also successfully extended to the one-pot synthesis of enamides from terminal alkynes.
- Anbarasan, Pazhamalai,Ramachandran, Kuppan,Reddy, Angula Chandra Shekar,Reddy, Palagulla Maheswar
-
supporting information
p. 5649 - 5652
(2020/06/09)
-
- Rhodium-Catalyzed Rearrangement of S/Se-Ylides for the Synthesis of Substituted Vinylogous Carbonates
-
An efficient rhodium-catalyzed unprecedented oxa-[2,3]-sigmatropic rearrangement of sulfur ylide derived from α-thioesters/ketones and diazo carbonyl compounds has been accomplished for the synthesis of various sulfur-tethered vinylogous carbonates in good to excellent yields. Important features of the developed reaction include wide functional group tolerance, excellent chemo- and regioselectivity, and efficient rearrangement involving the carbonyl motif. The present reaction also equally works well with α-selenoesters for the synthesis of seleno-containing vinylogous carbonates.
- Reddy, Angula Chandra Shekar,Anbarasan, Pazhamalai
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supporting information
p. 9965 - 9969
(2019/12/24)
-
- Synthesis of α-arylthioacetones using TEMPO as the: C 3 synthon via a reaction cascade of sequential oxidation, skeletal rearrangement and C-S bond formation
-
Here, we present an unprecedented pathway to α-sulfenylated carbonyl compounds from commercially available thiols and universally employed TEMPO and its analogues, which act as C3 synthons through skeletal rearrangement under simple and metal-f
- Zou, Jiao-Xia,Jiang, Yi,Lei, Shuai,Yin, Gao-Feng,Hu, Xiao-Ling,Zhao, Quan-Yi,Wang, Zhen
-
supporting information
p. 2341 - 2345
(2019/03/07)
-
- Cs2CO3-promoted methylene insertion into disulfide bonds using acetone as a methylene source
-
An efficient halogen-free Cs2CO3-promoted methylene insertion into disulfide bonds has been achieved using acetone as a methylene source under mild conditions. This method provides a convenient and practical route to dithioacetals in up to 96% yield with good functional group compatibility.
- Chen, Qian,Yu, Guodian,Wang, Xiaofeng,Huang, Yulin,Yan, Yan,Huo, Yanping
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supporting information
p. 4086 - 4089
(2018/06/12)
-
- Preparation method and application of novel ionic binuclear Schiff base titanium complex
-
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.
- -
-
Paragraph 0079; 0080
(2018/04/03)
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- Total Synthesis of the Reported Structure of Stresgenin B Enabled by the Diastereoselective Cyanation of an Oxocarbenium
-
We report the first total synthesis of the reported structure of the heat shock protein expression inhibitor stresgenin B. The synthesis features (1) diastereoselective cyanation of an oxocarbenium intermediate en route to the synthetically challenging α-
- Chan, Wei Chuen,Koide, Kazunori
-
supporting information
p. 7798 - 7802
(2019/01/04)
-
- Thiophene compounds and applications of thiophene compounds serving as USP7 inhibitors and antitumor drugs
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The invention discloses compounds shown in the formula I or nitrogen oxides, pharmaceutically acceptable salt or solvate of the compounds, a preparation method of the compounds, and applications of the compounds in pharmacy, and particularly provides the applications of the compounds serving as USP7 inhibitors and antitumor drugs. Pharmacodynamic experiment results show that the compounds in the formula I have inhibition effects on a USP7 enzyme and also have proliferation inhibition effects on human colon cancer cells HCT-116. Therefore, the compounds can be used for preparing the drugs for preventing or treating diseases related to tumors. The formula I is shown in the description.
- -
-
Paragraph 0066; 0068; 0069
(2019/01/16)
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- Synthesis of a new series of Ni(II), Cu(II), Co(II) and Pd(II) complexes with an ONS donor Schiff base: Crystal structure, DFT study and catalytic investigation of palladium and nickel complexes towards deacylative sulfenylation of active methylenes and regioselective 3-sulfenylation of indoles: Via thiouronium salt formation
-
A series of Ni(ii), Cu(ii), Co(ii), and Pd(ii) complexes have been synthesized with a chelating Schiff base ligand coordinated to a metal center with ONS donor atoms. The ligand and complexes are characterized by elemental analysis and spectroscopic techniques like FT-IR, 1H-NMR, and UV-Visible spectroscopy. The single crystal structure of the Pd(ii) complex is obtained by X-ray diffraction analysis and exhibits slightly distorted square planar geometry. The structure is optimized by DFT, TD-DFT calculation to elaborate the electronic structure and NBO for the charge distribution analysis of the Pd(ii) complex. The synthesized Pd(ii) and Ni(ii) complexes as catalysts have been investigated in the C-S cross-coupling of indoles and active methylenes. The metal propelled regioselective transformation afforded 3-sulfenylated indoles while β-diketones favored deacylated monosulfenyl ketones in an excellent yield via thiouronium salt formation. The Pd(ii) complex displays slightly better reactivity whereas the Ni(ii) complex is cost-efficient. The method is fast, easy to handle and cost effective in terms of high reactivity of catalysts, use of non-toxic solvents, and cheaper aryl halides and thiourea replace conventional sulfur sources, providing a practical access to organic transformations.
- Devi, Namita,Sarma, Kuladip,Rahaman, Rajjakfur,Barman, Pranjit
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p. 4583 - 4595
(2018/04/03)
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- A sulfur-containing amino acid amide carbamate derivative and application thereof
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The invention belongs to the field of plant fungicides, and relates to sulfur-containing amino acid amide carbamate derivatives of which the general formulas I are shown in the description and pharmaceutically acceptable salts of the sulfur-containing amino acid amide carbamate derivatives. In the general formulas I, substituent groups R1, R2 and n are defined in the description. The invention further relates to preparation methods of compounds related to the general formulas I, special intermediates developed for the preparation of the compounds, and application of the compounds to prevention and control of plant diseases.
- -
-
Paragraph 0033-0034; 0036-0037
(2017/08/09)
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- A route to benzylic arylsulfoxides from β-ketosulfoxides
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The K2CO3-mediated benzylation of β-ketosulfoxides 4 with 2.0?equiv of benzylic halides 5 affords benzylic arylsulfoxides 6 in moderate yields along with trace amounts of chalcones 7. The products 6 are assumed to form in situ intermediates of sulfenate anions from β-ketosulfoxides which are commonly involved in carbon–sulfur bond formation. A plausible mechanism has been proposed.
- Chang, Meng-Yang,Cheng, Yu-Chieh,Chan, Chieh-Kai
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p. 4068 - 4075
(2016/07/06)
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- Fe-Mediated S-S Bond Cleavage and Its Application in the Synthesis of α-Arylthio Carbonyl Compounds
-
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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- α-Arylchalcogenation of acetone with diaryl dichalcogenide via metal-free oxidative C(sp3)-H bond functionalization
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Direct α-arylchalcogenation of acetone with diaryl dichalcogenides has been achieved by using a mixture of TBHP and DTBP oxidants at 120 °C without transition-metal catalyst via oxidative C(sp3)-H bond functionalization. The method exhibits good functional group tolerance and products were isolated in moderate to high yields.
- Yan, Guobing,Borah, Arun Jyoti,Wang, Lianggui,Pan, Zhangjin,Chen, Shuangshuang,Shen, Xuqian,Wu, Xiangmei
-
supporting information
p. 4305 - 4307
(2015/06/22)
-
- Disulfide-based metal-free α-sulfanylation of ketones
-
An eco-friendly methodology for the direct α-sulfanylation of ketones, has been developed. The procedure, based on the use of functionalized diaryldisulfides and catalyzed by d,l-proline, represents a mild and efficient approach for the preparation of α-arylthio-ketones.
- Vaquer, Andrea F.,Frongia, Angelo,Secci, Francesco,Tuveri, Enrica
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p. 96695 - 96704
(2015/11/24)
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- Stereoselective synthesis of the macrolactone core of (+)-neopeltolide
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A stereoselective synthesis of the macrolactone core of the potent anticancer agent neopeltolide is disclosed. The key steps of the synthesis include asymmetric allylation using Krische' protocol, conjugate reduction using MacMillan's methodology, and an
- Raghavan, Sadagopan,Samanta, Pradip Kumar
-
supporting information; experimental part
p. 2346 - 2349
(2012/07/01)
-
- Synthesis of 3,6-diazahomoadamantane
-
Condensation of 1-phenylsulfanylpropan-2-one with 1,3,6,8- tetraazatricyclo[4.4.1.13,8]dodecane gave 1-phenylsulfanyl-3,6- diazahomoadamantan-9-one which was reduced to 1-phenylsulfanyl-3,6- diazahomoadamantane, and the latter was subjected to desulfurization over Raney nickel to obtain previously unknown 3,6-diazahomoadamantane. Heating of 9-phenyl-3,6-diazahomoadamantan-9-ols with Raney nickel resulted in reduction of the hydroxy group with formation of 9-phenyl-3,6-diazahomoadamantanes. Pleiades Publishing, Ltd., 2012.
- Kuznetsov,Senan,Shukkur,Azzheurova,Serova
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experimental part
p. 119 - 122
(2012/05/20)
-
- Preparation and pharmacological evaluation of a novel series of 2-(phenylthio)benzo[b]thiophenes as selective MT2 receptor ligands
-
A series of N-(2-(5-fluoro-2-(4-fluorophenylthio)benzo[b]thiophen-3-yl) ethyl)acylamides was synthesized and evaluated for binding affinity and intrinsic activity at melatonin receptors. The affinity of each compound for the melatonin receptors was determined by binding studies on cloned human MT 1 and MT2 receptors expressed in CHO cells. Agonist and antagonist potency was measured on the [35S]GTPγS binding assay for the most interesting compounds. The new derivatives 8-14 showed modest to high selectivity (between 4 and 220) for MT2 receptors. The most selective compound, N-(2-(5-fluoro-2-(4-fluorophenylthio)benzo[b]thiophen-3-yl) ethyl)but-3-enamide (14), an MT2 ligand with affinity for the MT 2 receptor similar to that of melatonin and a 220-fold preference over MT1 receptors, acts as a partial agonist. In addition, N-(2-(5-fluoro-2-(4-fluorophenylthio)benzo[b]thiophen-3-yl)ethyl)propionamide (9), a nanomolar MT2 ligand with a good selectivity ratio (MT 1/MT2 = 51) shows antagonist activity on both melatonin receptors.
- Mésangeau, Christophe,Fraise, Mika?l,Delagrange, Philippe,Caignard, Daniel Henri,Boutin, Jean Albert,Berthelot, Pascal,Yous, Sa?d
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scheme or table
p. 1835 - 1840
(2011/05/06)
-
- An efficient fluorination of β-ketosulfones promoted by a room-temperature ionic liquid at ambient conditions under ultrasound irradiation using Selectfluor F-TEDA-BF4
-
The fluorination reaction involving a β-ketosulfones by Selectfluor was efficiently promoted by the ionic liquid, [Hbim]BF4 (IL) as a reaction medium with methanol as co-solvent at room temperature under ultrasonic irradiation to afford the corresponding mono and difluoro-β-ketosulfones in excellent yields. The advantages of this method include among others the use of a recyclable, non-volatile ionic liquid, which promotes this protocol under room temperature without the requirement of any added catalyst under ultrasonic irradiation.
- Heravi, Mohammad Reza Poor
-
body text
p. 1399 - 1402
(2011/10/08)
-
- SUBSTITUTED NICOTINAMIDES AS KCNQ2/3 MODULATORS
-
The invention relates to substituted nicotinamides, to processes for their preparation, to medicaments comprising these compounds and to the use of these compounds in the preparation of medicaments.
- -
-
Page/Page column 20
(2010/09/18)
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- 2-ethanethioamide in heterocyclic synthesis: Synthesis and characterization of several new pyridine and fused azolo- and azinopyridine derivatives
-
Pyridine-2(1H)-thione derivatives 3a,b were synthesized from the reaction of 1-(phenyl-sulfanyl)acetone (1) and cinnnamonitrile derivatives 2a,b. Compounds 3a,b reacted with different halogenated reagents 7a-f to give 2-S-alkylpyridine derivatives 8a-l, which could be, in turn, cyclized into the corresponding thieno[2,3-b]pyridine derivatives 9a-l. Compounds 9d,j reacted with acetic anhydride, formic acid, carbon disulfide, phenyl isothiocyanate, and nitrous acid to yield the corresponding pyrido[3′,2′:4,5]thieno[2, 3-d]pyrimidine 12a,b, 15a,b, 17a,b, 20a,b, and pyrido[3′,2′:4,5] thieno[2,3-d][1,2,3]triazinone derivatives 22a,b, respectively. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. Copyright Taylor & Francis Group, LLC.
- Elneairy, Mohamed A. A.,Eldin, Sanaa M.,Attia, Mohamed F. M.
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body text
p. 1346 - 1357
(2010/09/06)
-
- Ionic liquid promoted regio- and stereo-selective thiolysis of epoxides-A simple and green approach to β-hydroxy- and β-keto sulfides
-
A variety of epoxides underwent facile cleavage by thiols under the catalysis of 1-methyl-3-butylimidazolium bromide, [bmIm]Br, to produce the corresponding β-hydroxy sulfides with high regio- and stereo-selectivity. On the other hand, a specially designed basic ionic liquid, [bmIm]OH, efficiently catalyzes the thiolysis of ,β-epoxy ketones providing β-keto sulfides through simultaneous retro-aldol cleavages. The reactions are clean, high yielding, and do not require any organic solvent. The catalyst is also recycled. CSIRO 2007.
- Ranu, Brindaban C.,Mandal, Tanmay,Banerjee, Subhash,Dey, Suvendu S.
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p. 278 - 283
(2008/02/11)
-
- Synthesis, docking, and in vitro activity of thiosemicarbazones, aminoacyl-thiosemicarbazides and acyl-thiazolidones against Trypanosoma cruzi
-
A novel series of thiosemicarbazone and aminoacyl-thiazolidones derivatives were synthesized. Their structure suggests that these compounds could have anti-Trypanosoma cruzi activity. Biological evaluation indicates that some of these compounds are able t
- Leite, Ana Cristina Lima,de Lima, Renata Souza,Moreira, Diogo Rodrigo de M.,Cardoso, Marcos Verissimo de O.,Gouveia de Brito, Ana Carolina,Farias dos Santos, Luciene Maria,Hernandes, Marcelo Zaldini,Kiperstok, Alice Costa,de Lima, Ricardo Santana,Soares, Milena B.P.
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p. 3749 - 3757
(2007/10/03)
-
- Ionic liquid as catalyst and reaction medium: A simple, convenient and green procedure for the synthesis of thioethers, thioesters and dithianes using an inexpensive ionic liquid, [pmIm]Br
-
An easily accessible and inexpensive room temperature ionic liquid, 1-pentyl-3-methylimidazolium bromide, [pmIm]Br efficiently catalyzes the reaction of alkyl halides or acyl halides with thiols without any solvent at room temperature leading to the synthesis of thioethers and thioesters in high yields. This reaction has also been extended for the preparation of dithianes and transthioetherification. The ionic liquid is recovered and recycled for subsequent runs.
- Ranu, Brindaban C.,Jana, Ranjan
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p. 1811 - 1818
(2007/10/03)
-
- A facile and efficient method for the reduction of sulfoxides into sulfides with an Al-NiCl2·6H2O system
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It has been observed that alkyl aryl and dialkyl sulfoxides can be conveniently and rapidly converted to the corresponding sulfides with an Al-NiCl2-6H2O system in high yields. Ketones are not affected under these reaction conditions.
- Raju, B. Rama,Devi, Gitali,Nongpluh, Yoofisaca S.,Saikia, Anil K.
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p. 358 - 360
(2007/10/03)
-
- Indium(I) iodide-promoted cleavage of diaryl diselenides and disulfides and subsequent condensation with alkyl or acyl halides. One-pot efficient synthesis of diorganyl selenides, sulfides, selenoesters, and thioesters
-
Diphenyl diselenides and disulfides undergo facile cleavages by indium(I) iodide and the corresponding generated selenate and thiolate anions condense in situ with alkyl or acyl halides present in the reaction mixture. Thus, a simple, efficient, and general procedure has been developed for the synthesis of unsymmetrical diorganyl selenides, sulfides (thioethers), selenoesters, and thioesters by this one-pot reaction at room temperature.
- Ranu, Brindaban C.,Mandal, Tanmay
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p. 5793 - 5795
(2007/10/03)
-
- NaOH-Catalyzed Thiolysis of α,β-Epoxyketones in Water. A Key Step in the Synthesis of Target Molecules Starting from α,β -Unsaturated Ketones
-
NaOH (0.02-0.3 molar equiv) is an efficient catalyst for the thiolysis reactions of α,β-epoxy ketones with alkyl and aryl thiols in water. Thiolysis of 3,4-epoxyheptan-2-one (1) with thiols 2a-d has been accomplished in mild conditions (30 °C and pH 6 or
- Fringuelli, Francesco,Pizzo, Ferdinando,Vaccaro, Luigi
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p. 2315 - 2321
(2007/10/03)
-
- Diastereoselective synthesis and stereochemistry of (Z)-1-[3-aryl-2- (phenylsulfanyl)-2-oxiranyl]-1-ethanones
-
Diastereoselective synthesis of a series of (Z)-1-[3-aryl-2- (phenylsulfanyl)-2-oxiranyl]-1-ethanones was effected from the reaction of (Z)-4-aryl-3-(phenylsulfanyl)-3-buten-2-ones with alkaline hydrogen peroxide in tetrahydrofuran. The stereochemistry of
- Karthikeyan,Perumal,Selvaraj
-
p. 2379 - 2386
(2007/10/03)
-
- Synthesis, anti-mycobacterial, anti-trichomonas and anti-candida in vitro activities of 2-substituted-6,7-difluoro-3-methylquinoxaline 1,4-dioxides
-
A new series of 23 6,7-difluoro-3-methyl-2-phenylthio/phenylsulfonyl/ phenylsulfinyl/benzylamino/phenylamino-quinoxaline 1,4-dioxides variously substituted in the phenyl moiety, was synthesized and submitted to in vitro evaluation for anti-mycobacterial,
- Carta, Antonio,Loriga, Mario,Paglietti, Giuseppe,Mattana, Antonella,Fiori, Pier Luigi,Mollicotti, Paola,Sechi, Leonardo,Zanetti, Stefania
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p. 195 - 203
(2007/10/03)
-
- Dianion of sulfinylacetone as a synthetic equivalent of β-enolate of propionic acid: A novel synthesis of carboxylic acids from alkyl halides with three-carbon elongation
-
The reaction of the dianion of phenylsulfinylacetone with alkyl halides afforded β-keto sulfoxides, which were first chlorinated with hexachloroethane and then treated successively with KH and t-BuLi to give carboxylic acids in three-steps in moderate overall yields from the alkyl halides. This procedure affords a good method for a synthesis of carboxylic acids from alkyl halides with three-carbon elongation.
- Satoh, Tsuyoshi,Imai, Kentaro
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p. 602 - 604
(2007/10/03)
-
- Substituent-dictated partitioning of intermediates on the sulfide singlet oxygen reaction surface. A new mechanism for oxidative C-S bond cleavage in α-hydroperoxy sulfides
-
The reactions of singlet oxygen with 17 sulfides bearing either anion or radical stabilizing substituents are reported. The abilities of substituents to modify product compositions in both the oxidative cleavage and sulfide oxidation pathways are analyzed in terms of partitioning of the hydroperoxy sulfonium ylide intermediate. Evidence is presented that suggests that the hydroperoxy sulfonium ylide exists in both diradical and zwitterionic forms. In addition, both inter- and intramolecular pathways for decomposition of α-hydroperoxy sulfides are suggested to rationalize the substituent-dependent formation of oxidative C-S bond cleavage products.
- Toutchkine,Aebisher,Clennan
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p. 4966 - 4973
(2007/10/03)
-
- Humicola lanuginosa lipase-catalyzed enantioselective resolution of β-hydroxy sulfides: Versatile synthons for enantiopure β-hydroxy sulfoxides
-
Humicola lanuginosa lipase-catalyzed acylation of β-hydroxy sulfides provides both the (R)- and (S)-enantiomers in high enantiomeric purity. In two cases the resolved hydroxy sulfides were oxidized to give β-hydroxy sulfoxides in >99% e.e. The effect of substituents on enantioselectivity is discussed.
- Singh, Satwinder,Kumar, Subodh,Chimni, Swapandeep Singh
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p. 2457 - 2462
(2007/10/03)
-
- Convenient formation of 4-hydroxyalk-2-en-1-one functionality via a Knoevenagel-type carbon chain elongation reaction of aldehyde with 1-arylsulfinylalkan-2-one
-
A highly functionalized four-carbon unit, 4-hydroxyalk-2-en-1-one functionality [R2CH(OH)CH= CHCOR1], was conveniently prepared by a reaction of an aldehyde (R2CH2CHO) with a 1-(arylsulfinyl)alkan-2-one [ArS(O)CH2COR1] in the presence of diethylamine (Knoevenagel condition). Other functional groups, such as carbonyl and hydroxy groups, in both of the alkyl chains (R1, R2) did not prevent this reaction. This reaction was used to conveniently prepare (±)-(11E)-13-hydroxy-10-oxooctadec-11-enoic acid (14), having cytotoxic activity, and its analogues from undec-10-enoic acid in good yield.
- Nokami,Kataoka,Shiraishi,Osafune,Hussain,Sumida
-
p. 1228 - 1232
(2007/10/03)
-
- Chemoselective deoxygenation of sulfoxides with titanium tetraiodide
-
Chemoselective deoxygenation of sulfoxides was carried out using TiI4 as a reducing agent to give sulfides in good to excellent yields.
- Shimizu,Shibuya,Hayakawa
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p. 1437 - 1438
(2007/10/03)
-
- A new method for the reductive cleavage of S-S bond by the system of Cp2TiCl2/i-BuMgBr/THF and its application in synthesis of α-alkylthio carbonyl compounds
-
The reduction of disulfides by Cp2TiCl2/i-BuMgBr/THF led to nucleophilic sulfides [Cp2TiSR]. This species reacted with α-bromo carbonyl compounds to give α-alkylthio carbonyl compounds in high yields.
- Huang,Zheng
-
p. 1297 - 1301
(2007/10/03)
-
- Highly chemoselective α-diazo carbonyl insertion reactions into N-H and S-H bonds catalysed by [RuCl(η5-C5H5)(PPh3)2]
-
Complex [RuCl(η5-C5H5)(PPh3)2], in chloroform at 60 deg C, catalyses the chemoselective insertion of α-diazo carbonyl compounds into N-H and S-H bonds to afford α-keto-amines and α-keto-thioethers.
- Del Zotto, Alessandro,Baratta, Walter,Rigo, Pierluigi
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p. 3079 - 3082
(2007/10/03)
-
- Enantioselective synthesis of α-hydroxy thioesters via oxazaborolidine- mediated reduction of α-phenylthio enones
-
α-Phenylthio-α,β-alkenones (2), readily available by Pd(II)-catalysed coupling of (E)-1 phenylthio-1-tributylstannylhex-1-ene with the corresponding acid chlorides have been treated with borane in the presence of phenylglycine- or proline-derived oxazaborolidines to afford 2-phenylthio-2- alken-1-ols (3) with good to excellent enantioselectivities. Ozonolysis of 3 provides a new and efficient route to chiral α-hydroxy thioesters 4.
- Berenguer, Ramon,Cavero, Marta,Garcia, Jordi,Munoz, Montse
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p. 2183 - 2186
(2007/10/03)
-
- Reactions of Vinyl Sulfoxides with Magnesium Amides. One-Pot Synthesis of Symmetrical and Unsymmetrical β-(Dialkylamino) Dithioacetals
-
Vinyl sulfoxides (PhSOCR1=CHR2: R1 = H, Me, or Ph; R2 = H or Me) were treated with (dialkylamino)magnesium reagents, generated in situ from the reaction of EtMgBr with secondary amines (R3R4NH: R3 = Et, i-Pr, or Bn; R4 = Me, Et, or i-Pr) in refluxing Et2O for 1 h, and stirring at room-temperature overnight gave the corresponding symmetrical β-(dialkylamino) dithioacetals [(PhS)2CR1CHR2NR3R4] in 24-84% yields. When the (diethylamino)magnesium reagent was treated with appropriate thiols (RSH; R = p-ClC6H4 or Bn) prior to the interaction with phenyl vinyl sulfoxide, the corresponding unsymmetrical β-(diethylamino) dithioacetals [(PhS)(RS)CHCH2NEt2] were produced in 63-67% yields.
- Kawakita, Masataka,Yokota, Kouichi,Akamatsu, Hideki,Irisawa, Susumu,Morikawa, Osamu,Konishi, Hisatoshi,Kobayashi, Kazuhiro
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p. 8015 - 8017
(2007/10/03)
-
- A novel reaction of N-phenylthiocaprolactam: The α-sulfenylation of ketones under mild conditions
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N-phenylthiocaprolactam (2) reacts with the enolate anions of aliphatic, aromatic or cyclic ketone 1a-e, to give the corresponding α-phenylthioketones 3a-e. This reaction proceeds with high yields of monosulphenylation (80-97%) in DMSO under mild conditions (potassium ter-butoxide, 25°C, 10 min).
- Foray, Gabriela,Penenory, Alicia B.,Rossi, Roberto A.
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p. 2035 - 2038
(2007/10/03)
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- Sulfur substituted small-ring heterocycles
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The synthesis of epoxy sulfines and sulfonyl azirines is described.
- Zwanenburg,Philipse,Verstappen,Gieling
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p. 453 - 454
(2007/10/03)
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- New hypoxia-selective cytotoxines derived from quinoxaline 1,4-dioxides
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A new series of quinoxaline 1,4-dioxides, structurally related to the benzotriazine tirapazamine 1 have been prepared starting from 5,6-dichlorobenzofuroxane 2. The Beirut reaction between 2 and alkyl or aryl thiopropanones afforded the 2-methyl-3-alkyl(a
- Monge,Palop,Gonzalez,Martinez-Crespo,Lopez De Cerain,Sainz,Narro,Barker,Hamilton
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p. 1213 - 1217
(2007/10/02)
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- Synthesis and anticancer activity of new phenyl-ring substituted 4-morpholino-1-phenylthio-2-butanones [Mannich bases]
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The preparation of phenyl-ring substituted 4-morpholino-1-phenylthio-2-butanones 4a-e is described. These compounds were evaluated against P-388 leukemia and human cancer rhinopharynx KB cells in vitro; some compounds were found to exhibit activity agains
- Siatra-Papastaikoudi,Tsotinis,Chinou,Roussakis
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p. 221 - 223
(2007/10/02)
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- Molecular recognition in aqueous media. new binding studies provide further insights into the cation-π interaction and related phenomena
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We describe a large number of binding studies in aqueous media designed to provide new insights into noncovalent binding interactions, especially the cation-π interaction. The studies include 7 different hosts, over 70 guests, and over 150 new binding constants. In addition to the now standard NMR methods, circular dichroism has proven to be an especially useful tool for determining aqueous binding constants. We have found that, in addition to the alkyliminium and tetraalkylammonium guests we have studied previously, sulfonium and guanidinium guests also show substantial cation-π effects. Bromination of the host greatly enhances its binding ability in a general fashion, primarily as a result of hydrophobic interactions. Addition of methoxy groups did not enhance binding, apparently as a result of a collapse of the host into a conformation that is not suitable for binding. Replacement of two benzene rings of the host by furans or thiophenes also did not enhance binding. Ab initio calculations provide a rationalization for this effect and suggest a clearer model for the cation-π interaction.
- Kearney, Patrick C.,Mizoue, Laura S.,Kumpf, Robert A.,Forman, Jonathan E.,McCurdy, Alison,Dougherty, Dennis A.
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p. 9907 - 9919
(2007/10/02)
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- Effects of adjacent acceptors and donors on the stabilities of carbon-centered radicals
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The radical stabilization energies (RSEs) for 21 radicals, GCH2*, where G is an electron donor or acceptor group, were estimated from differences in homolytic C-H bond dissociation energies (ABDEs relative to that of methane). These RSEs were found to agree reasonably well in order with theoretically calculated RSEs that have been reported and with those obtained by averaging RSEs from nine different methods (a literature RRSx scale). But the RSEs estimated from ΔBDEs were almost without exception larger because the theoretical calculations and RRSx method greatly underestimate the size of most RSEs. The RSEs for GCH2* radicals were found to be enhanced to the extent that G is able to delocalize an odd electron on an adjacent carbon atom and were diminished by the presence of electron-withdrawing properties in G. Most groups stabilize the radical, but when the electron-withdrawing effect of the group is large, as in F3C? and Me3N+CH2? radicals, the net effect is to destabilize the radical relative to the methyl radical. The RSEs of 12 radicals of the type RSC?HG or PhSC?HG, relative to that of the GCH2? radical, were found to increase progressively as the acceptor group G was changed along the series Ph, fluorenyl (Fl), CO2Et, CN, COMe, and COPh. The RSEs of these donor-acceptor radicals were all smaller than the sum of the RSEs of the singly-substituted radicals, GCH2? and PhSCH2? (or RSCH2?). The effects of a second PhS or like donor and of a second acceptor on the RSEs were also determined. Examination of the RSEs of GC?(Ph)CN radicals indicates that the interactions of G and CN in the GC?CN moieties, with G = MeO, EtS, or c-C5H10N, are not synergistic as has been claimed from ESR studies.
- Bordwell,Zhang, Xian-Man,Alnajjar, Mikhail S.
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p. 7623 - 7629
(2007/10/02)
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- A New Fragmentation Reaction of γ-Oxosulfonium Methylides
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Reactions of sulfonium methylides attached to a 5- or 6-membered cycloalkanone undergo the ring-fission as a major reaction course to give α-methylene-ω-(phenylthio)carboxylates, whereas sulfonium methylides attached to a larger ring give α-methylenecycloalkanones predominantly.Reactions of the acyclic compounds are also examined.
- Watanabe, Yoshihiko,Takeda, Toyonori,Anbo, Keiji,Ueno, Yoshio,Toru, Takeshi
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p. 159 - 162
(2007/10/02)
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- Reactions of Carbonyl Compounds with Benzyl Chloromethyl Ether of Diiodomethane in the Presence of Samarium(II) Iodide or Metallic Samarium. New Routes to 1,2-Diols, Iodohydrins and Cyclopropanols
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Carbonyl compounds react with benzyl chloromethyl ether in the presence of samarium(II) iodide to afford the corresponding addition products which, when subsequently hydrogenolysed, yield 1,2-diols.Simple aldehydes and ketones react with diiodomethane in the presence of samarium metal to give iodohydrins in good yields.Under similar reaction conditions, α-halogeno substituted ketones and aromatic 1,4-diketones are converted into cyclopropanols.These cyclopropanations have been shown to rpoceed through the initial generation of samarium enolates, followed by the Simmons-Smith type reaction.A novel transformation of esters to cyclopropanols via tandem one-carbon homologation is also described.
- Imamoto, Tsuneo,Hatajima, Toshihiko,Takiyama, Nobuyuki,Takeyama, Toshiaki,Kamiya, Yasuo,Yoshizawa, Takeshi
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p. 3127 - 3135
(2007/10/02)
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- Inter- and Intramolecular Hetero-Diels-Alder Reactions, 37. Syntheses of the 3-Amino Sugar Glycosides rac-4-Deoxydaunosaminide, rac-4-Deoxyristosaminide, and rac-Acosaminide
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The hetero-Diels-Alder reaction of the phenylthio-activated N-monoacyl- and N,N-diacyl-enamino ketones 8a-c containing a methyl group at position 2 of the oxadiene with the electron-rich dienophiles 9a-c yields the exo/endo adducts 10a-d and 11a-d in 82-95percent yield with the endo adducts as the main products.The enamino ketone 8d with a S-ethyl group at C-3 does not react.Hydrogenation of 11a with Raney nickel in THF leads to the desulfurized dihydropyran 12, whereas in MeOH gives stereoselectively the perhydrophthalimido derivative 13, which, after deprotection, yieldsthe β-methyl glycoside 14 of rac-4-deoxydaunosamine.Under similar conditions 10c is converted into the β-ethyl glycoside 15 of rac-N-benzoyl-4-deoxyristosamine.Stereoselective hydroboration of 12 affords 17 and subsequent cleavage of the protecting group leads to the β-methyl glycoside 18 or rac-acosamine.
- Tietze, Lutz F.,Hartfiel, Uwe,Huebsch, Thomas,Voss, Edgar,Bogdanowicz-Szwed, Krystyna,Wichmann, Juergen
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p. 275 - 281
(2007/10/02)
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- CONFORMATIONAL STUDY OF α-PHENYLTHIOCARBONYL COMPOUNDS
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Electrical and electrooptical characteristics of α-phenylthioacetone, α-phenylthiocyclohexanone, and 3α-phenylthio-4-caranone have been determined and used in establishing the structure of the compounds in solution.It has been shown that the preferred con
- Kazakova, E. Kh.,Davletshina, G. R.,Vul'fson, S. G.,Chernova, A. V.
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p. 2162 - 2166
(2007/10/02)
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- TANDEM ONE-CARBON HOMOLOGATION OF ESTERS TO CYCLOPROPANOLS
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Esters react with diiodomethane in the presence of samarium to afford 1-substituted cyclopropanols in good yields.
- Imamoto, Tsuneo,Kamiya, Yasuo,Hatajima, Toshihiko,Takahashi, Harumi
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p. 5149 - 5152
(2007/10/02)
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