- Thiol-free chemoenzymatic synthesis of β-ketosulfides
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A preparation of β-ketosulfides avoiding the use of thiols is described. The combination of a multicomponent reaction and a lipase-catalysed hydrolysis has been developed in order to obtain high chemical diversity employing a single sulfur donor. This methodology for the selective synthesis of a set of β-ketosulfides is performed under mild conditions and can be set up in one-pot two-step and on a gram-scale.
- Heredia, Adrián A.,López-Vidal, Martín G.,Kurina-Sanz, Marcela,Bisogno, Fabricio R.,Pe?é?ory, Alicia B.
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p. 378 - 387
(2019/02/20)
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- Substituted α-Sulfur Methyl Carbanions: Effective Homologating Agents for the Chemoselective Preparation of β-Oxo Thioethers from Weinreb Amides
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The proper generation of α-thiomethyllithium reagents via reductive lithiation or deprotonation followed by reaction with variously functionalized Weinreb amides represents an excellent method to access β-oxo thioethers. The procedure is adaptable to alky
- Senatore, Raffaele,Ielo, Laura,Urban, Ernst,Holzer, Wolfgang,Pace, Vittorio
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supporting information
p. 2466 - 2470
(2018/05/03)
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- Rh/DuanPhos-Catalyzed Asymmetric Hydrogenation of β-Acetylamino Vinylsulfides: An Approach to Chiral β-Acetylamino Sulfides
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Rh/DuanPhos-catalyzed asymmetric hydrogenation of challenging β-acetylamino vinylsulfides has been developed, affording chiral β-acetylamino sulfides with high yields and excellent ee's (up to 99% ee). This novel methodology provides an efficient and concise synthetic route to chiral β-acetylamino sulfides. The potential utility of this protocol in the synthesis of Apremilast has also been disclosed.
- Gao, Wenchao,Lv, Hui,Zhang, Xumu
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p. 2877 - 2880
(2017/06/07)
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- Stevens rearrangement of thioethers with arynes: A facile access to multi-substituted β-keto thioethers
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An effective method for the synthesis of multi-substituted β-keto thioethers via Stevens rearrangement of simple β-keto thioethers with arynes has been developed. In these reactions, successive C-S/C-H/C-C bonds were formed in one pot under mild and transition-metal free conditions to afford multi-substituted β-keto thioethers in moderate to good yields.
- Xu, Xiao-Bo,Lin, Zi-Hua,Liu, Yuyin,Guo, Jian,He, Yun
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supporting information
p. 2716 - 2720
(2017/04/03)
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- Palladium-catalyzed methylation of alkynyl C(sp)-H bonds with dimethyl sulfonium ylides
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A novel palladium-catalyzed methylation protocol for the synthesis of methyl-functionalized internal alkynes has been established. This methylation method is achieved through a C(sp)-C(sp3) bond formation process and represents a new synthetic application of sulfonium ylides.
- Liu, Yan-Yun,Yang, Xu-Heng,Huang, Xiao-Cheng,Wei, Wen-Ting,Song, Ren-Jie,Li, Jin-Heng
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p. 10421 - 10426
(2013/11/06)
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- One-pot preparation of arylethynyl sulfides and bis(arylethynyl) sulfides
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An efficient preparation for arylethynyl sulfides 1 and bis(arylethynyl) sulfides 2 has been accomplished through a one-pot, three-step strategy that starts from arylethanonyl sulfides and bis(arylethanonyl) sulfides, respectively, without the use of various terminal arylacetylenes as substrates. When lithium hexamethyldisilazane (LHMDS), ClP(O)(OEt)2, and LHMDS were sequentially added to a tetrahydrofuran solution of different substrates [arylethanonyl sulfides or bis(arylethanonyl) sulfides], 1 or 2 were obtained in moderate to good yields. The reaction procedure involves the formation of an enol phosphate and a subsequent base-induced elimination. An efficient preparation of arylethynyl sulfides 1 and bis(arylethynyl) sulfides 2 has been accomplished by a one-pot, three-step strategy that starts from arylethanonyl sulfides and bis(arylethanonyl) sulfides, respectively, to give 1 and 2 in moderate to good yields. The reaction mechanism involves the formation of an enol phosphate that undergoes a subsequent base-induced elimination. Copyright
- Su, Qiong,Zhao, Zi-Jian,Xu, Feng,Lou, Peng-Cai,Zhang, Kai,Xie, De-Xun,Shi, Lei,Cai, Qing-Yun,Peng, Zhi-Hong,An, De-Lie
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p. 1551 - 1557
(2013/04/23)
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- Gold-catalyzed carbene transfer to alkynes: Access to 2,4-disubstituted furans
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Furans of gold: The first example of a gold-catalyzed intermolecular addition of carbon ylides to terminal alkynes is reported (see scheme; DCE=dichloroethane, Tf=trifluoromethanesulfonyl). Subsequent intramolecular trapping of the generated gold carbene completes a formal [3+2] cycloaddition, which represents a novel synthesis of 2,4-disubstituted furans. Copyright
- Kramer, Soren,Skrydstrup, Troels
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supporting information; experimental part
p. 4681 - 4684
(2012/06/30)
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- An efficient and odorless synthesis of thioethers using 2-[Bis(alkylthio)methylene]-3-oxo-N-o-tolylbutanamides as thiol equivalents
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Using 2-[bis(alkylthio)methylene]-3-oxo-N-o-tolylbutanamides 1 as odorless thiol equivalents, an efficient and odorless synthesis of thioethers has been developed. Promoted by NaOH in EtOH, the cleavage of 1 commences to generate thiolate anions, and the generated thiolate anions then react with halides to give various thioethers in good yield. It is noteworthy that only a very faint odor of thiols can be perceived during both the reaction and the workup. Using 2-[bis(alkylthio)methylene]-3-oxo-N-o-tolylbutanamides as odorless thiol equivalents, an efficient and odorless synthesis of thioethers has been developed. Promoted by NaOH in EtOH, the cleavage of 2-[bis(alkylthio)methylene] -3-oxo-N-o-tolylbutanamides commences to generate thiolate anions, and the generated thiolate anions then react with halides to give various thioethers in good yield. Copyright
- Yu, Haifeng
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experimental part
p. 367 - 371
(2012/04/23)
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- An efficient and practical synthesis of aryl and hetaryl α-keto esters
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A general and highly efficient method was developed for the synthesis of -keto esters by oxidative esterification of 2,2-dibromo-1-(het)arylethanones by sequential treatment with dimethyl sulfoxide and an alkanol. The versatility of the reaction was established by synthesizing a range of -keto esters by treatment of 2,2-dibromoethanones, derived from aryl or hetaryl ketones, with di-methyl sulfoxide and a cyclic or acyclic primary or secondary alcohol. The mechanism of the reaction was established by means of a detailed study. Georg Thieme Verlag Stuttgart · New York.
- Raghunadh, Akula,Meruva, Suresh Babu,Kumar, Nuka Anil,Kumar, Gudla Santosh,Rao, L. Vaikunta,Syamkumar
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p. 283 - 289
(2012/03/26)
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- Rhodium-catalyzed α-methylthiolation reaction of unactivated ketones using 1,2-diphenyl-2-methylthio-1-ethanone for the methylthio transfer reagent
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In the presence of catalytic amounts of RhH(PPh3)4, 1,2-bis(diphenylphosphino)ethane (dppe), and dimethyl disulfide, ketones without α-activating groups were α-methylthiolated with 1,2-diphenyl-2-methylthio-1-ethanone giving α-methylthio ketones. The reaction of unsymmetrical ketones proceeded at the more substituted carbons. The initial formation of kinetic α-methylthiolated products followed by their rearrangement to thermodynamic products was observed in the reaction of α-phenyl ketones. Aldehydes, phenylacetate, and phenylacetonitrile were also α-methylthiolated under these conditions.
- Arisawa, Mieko,Toriyama, Fumihiko,Yamaguchi, Masahiko
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experimental part
p. 2305 - 2312
(2011/04/22)
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- Reaction of ammonium ylides with alkyl thiocyanates in aqueous and non-aqueous media
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Reaction of ammonium ylides with alkyl thiocyanates in aqueous and non-aqueous media is described. The reaction leads to alkyl thio-substituted acetophenones via addition of ammonium ylides to alkyl thiocyanates in organic solvents or in situ generated thiolate anions in aqueous media.
- Kianmehr, Ebrahim,Mirza Agha, Mansoureh,Estiri, Hamid
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experimental part
p. 409 - 411
(2011/07/30)
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- QUINOLINE DERIVATIVES, PHARMACEUTICAL COMPOSITIONS COMPRISING THEM, AND THEIR USE IN TREATING CENTRAL NERVOUS SYSTEM AND PERIPHERAL DISEASES
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Compounds of Formula (I) wherein R1, R2, n and R3 are as described in the specification, pharmaceutically-acceptable salts, methods of making, pharmaceutical compositions containing and methods for using the same.
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Page/Page column 14; 15
(2008/12/07)
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- NaOH-promoted thiolysis of oxiranes using 2-[bis(alkylthio)methylene]-3- oxo-N-o-tolylbutanamides as odorless thiol equivalents
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A convenient and efficient protocol for the thiolysis of oxiranes using 2-[bis(alkylthio)methylene]-3-oxo-N-o-tolylbutanamides as thiol equivalents has been developed. Promoted by sodium hydroxide (NaOH) in ethanol at room temperature, the cleavage commences and the generated thiolate anions undergo nucleophilic addition in situ. β-Hydroxy Sulfides were obtained in high yields along with good β-regioselectivity, and trans β-hydroxy Sulfides were also isolated. The thiolysis of one α,β-epoxyketone product with the thiol equivalents was accomplished to afford the corresponding α-carbonyl sulfides in excellent yields. In all the cases, 3-oxo-N-o-tolylbutanamide, the precursor of the thiol equivalents, could be recovered in the novel thiolysis process as a byproduct in good yield. Georg Thieme Verlag Stuttgart.
- Yu, Haifeng,Dong, Dewen,Ouyang, Yan,Wang, Yan,Liu, Qun
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p. 151 - 155
(2008/03/13)
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- The synthesis of chiral β-ketosulfoxides by enantioselective oxidation and their stereocontrolled reduction to β-hydroxysulfoxides
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Various chiral non-racemic β-ketosulfoxides, a class of compounds frequently used in asymmetric synthesis, were prepared in good yields by tert-butyl hydroperoxide oxidation of the corresponding sulfides in the presence of a complex between titanium and (
- Cardellicchio, Cosimo,Omar, Omar Hassan,Naso, Francesco,Capozzi, Maria Annunziata M.,Capitelli, Francesco,Bertolasi, Valerio
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p. 223 - 229
(2007/10/03)
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- Rhodium(II)-mediated reactions of thiobenzoylketene S,N-acetals with α-diazo carbonyl compounds: Synthesis of 2-substituted 3-alkylamino-5-phenylthiophenes
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Treatment of 3-methylamino-3-methylsulfanyl-1-phenylpropenethione 1 with excess (2.5 equiv.) α-diazo carbonyl compounds such as α-diazoketones and α-diazoesters in the presence of a catalytic amount of Rh(II) acetate in CH2Cl2 at rt gave 2-acyl- or 2-aroyl-3-methylamino-5-phenylthiophenes and alkyl 3-methylamino-5-phenylthiophene-2-carboxylates, respectively, as major products along with 1-phenyl-2-methylsulfanylethanones. The formation of the major products indicates that the carbenes or carbenoids generated interact initially with the thione sulfur of 1.
- Song, Hyun Min,Kim, Kyongtae
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p. 2414 - 2417
(2007/10/03)
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- New antifungal 1,2,4-triazoles with difluoro(substituted sulfonyl)methyl moiety
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New 1,2,4-triazoles (2) having a difluoro(substituted sulfonyl)methyl moiety were designed and synthesized via α,α-difluoro-α-(substituted thio)acetophenones (3). Compounds (2) showed potent antifungal activities against C. albicans, C. krusei, A. flavus
- Eto,Kaneko,Takeda,Tokizawa,Sato,Yoshida,Namiki,Ogawa,Maebashi,Ishida,Matsumoto,Asaoka
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p. 173 - 182
(2007/10/03)
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- 4-hydroxycoumarin derivatives. Part XIII (1). 3-(2'-alkylthioethyl-1'-phenyl)-4-hydroxycoumarins and their oxidation products
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3-(2'-Methylthioethyl-1'-phenyl)-4-hydroxycoumarin and 3-(2'-ethylthioethyl-1'-phenyl)-1-hydroxycoumarin were synthesized. Acetylation of these compounds with acetic anhydride and pyridine yielded respective 4-acetylcoumarins while appropriate sulfoxides and sulfones were obtained by oxidation of alkylthio substituens with H2O2. 3-(2'-ethylthioethyl-1'-phenyl)-4-hydroxycoumarin methylated with diazomethane gave 3-(2'-ethylthioethyl-1'-phenyl)-4-methoxycoumarin and 2-methoxy-3-(2'-ethylthioethyl-1'-phenyl)-chromone.
- Sulko, Jerzy
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p. 319 - 324
(2007/10/03)
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- Novel and efficient insertions of carbons carrying O-, S-, and N-Linked substituents: Synthesis of α-alkoxyalkyl, α-(Alkylthio)alkyl, and α-(Carbazol-9-yl)alkyl ketones
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A wide variety of benzotriazolyl-stabilized anions 2, obtained by the lithiation of 1-(α-alkoxyalkyl)-, 1-[α-(alkylthio)alkyl]-, and 1-[α-(carbazol-9-yl)alkyl]benzotriazoles 1, on reaction with aliphatic and aromatic aldehydes and ketones, followed by rearrangement induced by heating in the presence of zinc bromide, furnish one-carbon-homologated α-alkoxyalkyl, α-(alkylthio)alkyl, and α-(carbazol-9-yl)alkyl ketones 4 in simple one-pot operations in good yields with excellent regioselectivity. In several alkoxymethylene insertions, intermediate 2-alkoxyoxiranes were separated in good yields, demonstrating the epoxide mechanism for the rearrangements and providing a facile approach to poly substituted 2-alkoxyoxiranes, another class of important compounds.
- Katritzky, Alan R.,Xie, Linghong,Serdyuk, Larisa
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p. 7564 - 7570
(2007/10/03)
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- The Electrolytic Reduction of p-Substituted α-(Methylsulfinyl)-α-(methylthio)acetophenones in Acetonitrile
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p-Substituted α-(methylsulfinyl)-α-(methylthio)-acetophenones (1) exhibit on polarographic reduction, three wavwes.The two last waves corespond to the reductions of p-substituted α-(methylthio)acetophenones (2) and p-substituted acetophenones respectively
- Kunugi, Akira,Takahashi, Norimasa,Abe, Kyo,Hirai, Taketsugu
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p. 2055 - 2057
(2007/10/02)
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- Ylidions: A New Reactive Intermediate Prepared by Photosensitized One-Electron Oxidation of Phenacyl Sulfonium Ylides
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The chemistry of a series of phenacyl sulfonium ylides was studied.Their photosensitized one-electron oxidation by 9,10-dicyanoanthracene generates ylidions, a new class of radical cation intermediates.In some cases, the ylidions cleave to form a free alkyl radical and a cation; in others, they are attacked by nucleophiles or by an alkene.The chemical properties displayed by the phenacyl sulfonium ylidions appear to be controlled primarily by the nature of the sulfur-bound alkyl groups.The direct photolysis and thermolysis of the phenacyl sulfonium ylides was examined for comparison with their one-electron oxidation.Some of the ylides undergo the Stevens rearrangement either when heated or photolyzed.Contrary to an earlier report, there is no evidence that direct photolysis of a phenacyl sulfonium ylide leads to formation of benzoylcarbene.
- Zhang, Jian-Jian,Schuster, Gary B.
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p. 7149 - 7155
(2007/10/02)
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- A CONVENIENT GENERAL ACCESS TO α-SULFENYLATED ACETOPHENONES AND ALKANONES
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Friedel-Crafts acylation of arenes with methylthio- (1) or phenylthio-acetyl chloride (2) provides ready access to α-methylthio- or α-phenylthio-substituted acetophenones.The acyl chlorides 1 and 2 reacted also with organoaluminium reagents to give α-sulfenylated alkanones.
- Ishibashi, Hiroyuki,Takamuro, Iwao,Mizukami, Yo-ichi,Irie, Maki,Ikeda, Masazumi
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p. 443 - 452
(2007/10/02)
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- Electroreduction of Organic Compounds, 9. - Convenient Electrochemical Preparation of Thioacetals from Dithioesters
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Thioacetals are obtained as main products on electroreduction of alkyl dithiocarboxylates of various types in the presence of dimethyl sulfate in methanol. (Z)- and (E)-1,2-diaryl-1,2-bis(methylthio)ethenes are formed as byproducts.No reduction to form be
- Drosten, Gisela,Mischke, Peter,Voss, Juergen
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p. 1757 - 1762
(2007/10/02)
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- α-(METHYLTHIO)BENZYL SULFONES AS SYNTHETIC INTERMEDIATES. III. A NEW ROUTE TO p-SUBSTITUTED PHENYL ALKYL KETONES.
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Key words: Sulfones.Ketones.Thermal decomposition.Benzylic group.Alkylthio group.Alkylation.
- Wladislaw, B.,Marzorati, L.,Uchoa, R. B.
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- Thioaldehyde Diels-Alder Reactions
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Thioaldehydes containing virtually any α-substitutent can be generated by photofragmentation of phenacyl sulfides.Donor-substituted derivatives are reactive toward electron-rich dienes and give 2 + 4 cycloadducts with regiochemistry corresponding to advan
- Vedejs, E.,Eberlein, T. H.,Mazur, D. J.,McClure, C. K.,Perry, D. A.,et al.
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p. 1556 - 1562
(2007/10/02)
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- A VERY EFFICIENT PREPARATION OF 1,2-DIKETONES
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Treatment of α-thiomethylketones with CuCl2-CuO in aqueous acetone affords the corresponding 1,2-dicarbonyl compounds.
- Carre, M. C.,Caubere, P.
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p. 3103 - 3106
(2007/10/02)
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- Synthesis of Unsymmetrical Functionalised Organic Sulphides
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Acyclic thioiminium salts and the condensed thiazolium salts in the presence of aqueous sodium hydroxide as such or under base catalyzed phase transfer catalysis conditions react with appropiate organic halides to provide corresponding unsymmetrical functionalized organic sulphides.With aqueous sodium hydroxide, thioiminium salts provide the disulphides corresponding to incipient thiol.
- Singh, Harjit,Batra, Manohar S.,Singh, Paramjit
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p. 131 - 136
(2007/10/02)
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- REACTION OF ALDEHYDES AND KETONES WITH t-BUTYL BROMIDE-DIMETHYL SULPHOXIDE
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Reacting aldehydes and ketones with the "ButBr-Me2SO" system produces the corresponding α-bromoderivatives 2.In the case of ketones, where more than one regioisomer is possible, bromination is obtained exclusively at the more highly substituted α-position.With slight modifications of the reaction conditions (addition of Me2S, Me2SO) it is possible to obtain "in situ" formation of either dimethyl(2-oxo-phenylalkyl)sulphonium salts 3 or of α-methylthioderivatives 4.Dimethyl(1-methyl-2-oxo-2-phenylethyl)sulphonium bromide (3h) during crystallization undergoes spontaneous resolution of the two enantiomers, as demonstrated by single crystal X-ray analysis and absolute configuration assignment.
- Armani, E.,Dossena, A.,Marchelli, R.,Casnati, G.
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p. 2035 - 2040
(2007/10/02)
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- Synthesis of Unsymmetrical Thioethers Using Solid-Liquid Phase-transfer Catalysis
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The title compounds have been synthesised from appropriate organic halides and thioimminium salts (1) in moderate to good yields under solid-liquid phase-transfer catalysis using Triethylbenzylammonium chloride (TEBA) as a catalyst, solid KOH as a base in chloroform.
- Singh, Paramjit,Batra, Manohar S.,Singh, Harjit
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- A NEW METHOD FOR THE EVALUATION OF THE RELATIVE STABILITY OF ORGANOSULFUR RADICALS BY COMPETITIVE ELIMINATION TECHNIQUE
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The relative stability of various organosulfur radicals is estimated by competitive elimination technique using tributyltin radical and acetophenone derivatives having two different sulfur substituents at α and α positions.
- Ueno, Yoshio,Miyano, Tadaaki,Okawara, Makoto
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p. 443 - 446
(2007/10/02)
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- Synthesis of Functionalised, Unsymmetrical Organic Sulphides - Thioacetamide as a Sulphur Transfer Reagent
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In a novel approach, unsymmetrical organic sulphides (IIa-h) have been obtained from appropriate organic halides and sulphonium salts (I) - a source of incipient thiolate ions.
- Singh, Harjit,Malhotra, Nageshwar,Batra, Manohar S.
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p. 272 - 273
(2007/10/02)
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