- Synthesis and characterization of sulfide, sulfoxide and sulfone derivatives of thiopyran: antimicrobial evaluation
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Abstract: A series of thiopyran derivatives and their oxidized analogous forms were synthesized and characterized by FT-IR, 1H, 13C, 31P NMR and mass spectroscopy techniques. The antibacterial and antifungal activities of these synthesized materials were evaluated against Staphylococcus aureus and Bacillus subtilis, as Gram-positive bacteria, and Escherichia coli and Pseudomonas aeruginosa, as Gram-negative bacteria, as well as the fungus Candida albicans. The results revealed that thiopyran S,S-dioxides are the most effective against all the bacteria studied in this work. Furthermore, thiopyran S-oxides showed excellent antifungal activity against Candida albicans.
- Pasha, Ghasem Firouzzade,Asghari, Sakineh,Tajbakhsh, Mahmoud,Mohseni, Mojtaba
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- Simple and efficient preparation of reagents for thiopyran introduction: Methyl tetrahydro-4-oxo-2H-thiopyran-3-carboxylate, tetrahydro-4H-thiopyran-4- one, and 3,6-dihydro-4-trimethylsilyloxy-2H-thiopyran
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Tetrahydro-4H-thiopyran-4-one was prepared in >75% yield by treatment of dimethyl 3,3′-thiobispropanoate with NaOMe (generated in situ) in THF solution and decarboxylation of the resulting methyl tetrahydro-4-oxo-2H- thiopyran-3-carboxylate in refluxing 10% aqueous H2SO4. Reaction of tetrahydro-4H-thiopyran-4-one with Me3SiCl and Et 3N in CHCl3 gave the corresponding trimethylsilyl enol ether in near quantitative yield. The prepared reagents are useful for the synthesis of thiopyran-containing compounds. Georg Thieme Verlag Stuttgart.
- Ward, Dale E.,Rasheed, M. Abdul,Gillis, H. Martin,Beye, Garrison E.,Jheengut, Vishal,Achonduh, George T.
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- HCl-catalyzed stereoselective Mannich reaction in H2O-SDS system
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HCl-catalyzed Mannich reaction of cyclic ketone, aromatic aldehyde, and aromatic amine proceeded smoothly in water in the presence of SDS to afford the corresponding β-amino ketone with high anti selectivity.
- Akiyama, Takahiko,Matsuda, Keiichiro,Fuchibe, Kohei
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- Influence of the β-alkoxy group on the diastereoselectivity of aldol reactions of tetrahydro-4H-thiopyran-4-one with 4-alkoxytetrahydro-2H-thiopyran-3-carboxaldehydes
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The diastereoselectivity of the aldol reaction of tetrahydro-4H-thiopyran-4-one (3) with 1,4-dioxa-8-thiaspiro[4.5]decane-6-carboxaldehyde (9a) under a variety of conditions is examined. Under optimized conditions, three of the four possible diastereomers from this aldol reaction can be obtained selectively (3-16:1). Reactions of 9a with the Li, B, Mg(II), and Ti(IV) enolates of 3 and with the corresponding trimethylsilyl enol ether 4b in the presence of BF3·OEt2, SnCl4, or TiCl4 as promoters gave the Felkin adducts exclusively (>95%) as mixtures of syn (11a) and anti (12a) diastereomers. Use of the "amine-free" Li enolate of 3 gave 12a with a much higher diastereoselectivity (9:1) and yield (70%) than that obtained using the lithium diisopropylamide-generated Li enolate of 3 (2-3:1; 15-40%). The TiC14-promoted reaction of 4b with 9a gave 11a with excellent selectivity (16: 1). In contrast, the MgBr2·OEt2-promoted reaction of 4b with 9a gave the anti-Felkin adducts exclusively as a 3:1 mixture of syn (13a)/anti (14a) diastereomers. Similar aldol reactions of 3 with the cis and trans isomers of 4-(methoxy)methoxytetrahydro-2H-thiopyran-3-carboxaldehyde (9b and 9c) were examined to probe the influence of the ketal protecting group in 9a on the observed aldol diastereoselectivity. The results are rationalized by applying Evans' stereochemical model for merged 1,2- and 1,3-asymmetric induction (nonchelation), with the exception of the MgBr2· OEt2-promoted reactions of 4b with 9a, 9b, and 9c, which are accommodated by assuming chelation control. Comparison of the reactions of 9a, 9b, and 9c suggests that the ketal group in 9a uniquely allows high levels of either Felkin or anti-Felkin selectivity to be achieved.
- Ward, Dale E.,Sales, Marcelo,Man, Chuk C.,Shen, Jianheng,Sasmal, Pradip K.,Guo, Cheng
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- Hydrogenation of sulfoxides to sulfides under mild conditions using ruthenium nanoparticle catalysts
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The first demonstration of the hydrogenation of sulfoxides under atmospheric H2 pressure is reported. The highly efficient reaction is facilitated by a heterogeneous Ru nanoparticle catalyst. The mild reaction conditions enable the selective hydrogenation of a wide range of functionalized sulfoxides to the corresponding sulfides. The high redox ability of RuO x nanoparticles plays a key role in the hydrogenation.
- Mitsudome, Takato,Takahashi, Yusuke,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
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supporting information
p. 8348 - 8351
(2014/08/18)
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- Synthesis and reduction kinetics of sterically shielded pyrrolidine nitroxides
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A series of sterically shielded pyrrolidine nitroxides were synthesized, and their reduction by ascorbate (vitamin C) indicate that nitroxide 3, a tetraethyl derivative of 3-carboxy-PROXYL, is reduced at the slowest rate among known nitroxides, i.e., at a 60-fold slower rate than that for 3-carboxy-PROXYL.
- Paletta, Joseph T.,Pink, Maren,Foley, Bridget,Rajca, Suchada,Rajca, Andrzej
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p. 5322 - 5325
(2013/01/15)
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- Synthesis of 5 H-Imidazo[1,2-a]thiopyrano-[4',3':4,5]thieno[2,3-d]pyrimidin-5-one
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The enamino-ester, ethyl, 2-amino-4,7-dihydro-5H-thieno[2,3-c]thiopyrano-3-carboxylate (5) was prepared from tetrahydrothiopyran-4-one (4). Annelating reagent, 5-methyl-2-methylthioimidazoline (8) was prepared starting from 1, 2-diaminopropane (6) via 5-methyl-2-imidazolidinethione (7). The reaction of enamino-ester (5) with the annelating reagent (8) in HMPTA leaded to new 1,2,3,6,7,9-hexahydro-5H-imidazo[1,2-a]thiopyrano[4',3':4,5]thieno[2,3-d]pyrimidin-5-one (9) in good yield.
- Chowdhury, A. Z. M. Shaifullah,Khadker, M.M. Rahman,Bhuiyan, M. M. H.,Hossain, M. K.
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- Aminooxyamide tricyclic inhibitors of farnesyl-protein transferase
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Novel aminooxyamide tricyclic compounds and pharmaceutical compositions are disclosed which are inhibitors of the enzyme, farnesyl protein transferase. Also disclosed is a method of inhibiting Ras function and therefore inhibiting the abnormal growth of cells. The method comprises administering the novel aminooxyamide tricyclic compound to a biological system. In particular, the method inhibits the abnormal growth of cells in a mammals such as a human.
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- Syntheses of 4H-thiopyran-4-one 1,1-dioxides as precursors to sulfone-containing analogues of tetracyanoquinodimethane
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Synthetic routes to the unsubstituted 4H-thiopynan-4-one 1,1-dioxide (5a), 2,6-dialkyl-substituted, 2-aryl- or 2-heteroaryl-6-alkyl-substituted, 2,6-diaryl- or diheteroaryl-substituted, and 2-heteroaryl-6-aryl-substituted 4H-thiopyran-4-one 1,1-dioxides 5b-s are described. Sodium hydrosulfide hydrate in buffered aqueous alcohol can be used as a substitute for hydrogen sulfide gas for the introduction of sulfur to methyl acrylate, to 1,5-disubstituted-1,4-pentadien-3-ones 13, or to 1,5-disubstituted-1,4-pentadiyn-3-ones 17. The double dehydrogenation of 2,3,5,6-tetrahydrothiopyran-4-one 1,1-dioxides 13 with iodine-DMSO-sulfuric acid gives thiopyran-4-one 1,1-dioxides 5 in good yield and small amounts of 1,4-pentadien-3-ones 13. 2,3,5,6-Tetrahydrothiopyran-4-one 1,1-dioxide (9) and 5,6-dihydrothiopyran-4-one 1,1-dioxide (12), which lack aryl or heteroaryl substituents, give poor yields of 4H-thiopyran-4-one 1,1-dioxide (5a) with iodine-DMSO-sulfuric acid.
- Rule,Detty,Kaeding,Sinicropi
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p. 1665 - 1673
(2007/10/02)
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- A SIMPLE METHOD FOR THE PRODUCTION OF 1,5-DIHALOGENO-3-PENTANONES AND 1-BROMO-3-PENTANONE - PRECURSORS OF DIVINYL AND ETHYL VINYL KETONES
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The reaction of methyl 3-halogenopropionates with ethylmagnesium bromide in the presence of catalytic amounts of tetraisopropoxytitanium gave the corresponding 1-(2-halogenoethyl)cyclopropanols, the bromination of which with N-bromosuccinimide led to high yields of 1,5-dihalogeno-3-pentanones. 1-Bromo-3-pentanone was obtained by the acid-catalyzed opening of the three-membered ring of 1-(2-bromoethyl)cyclopropanol and also by the bromination of 1-ethylcyclopropanol.The reactions of 1,5-dibromo-3-pentanone with sodium carbonate and sodium sulfide led to good yields of divinyl ketone and 4-tetrahydrothiopyrone respectively.
- Sviridov, S. V.,Vasilevskii, D. A.,Kulinkovich, O. G.
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p. 1251 - 1253
(2007/10/02)
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- Preparation of 3-Substituted 4-Thianones and Their 1,1-Dioxides via Palladium Mediated Deallyloxycarbonylation
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3-Alkyl-4-thianones 4 (3-alkyl-thiacyclohexan-4-ones) can be conveniently prepared by the alkylation of 3-allyloxycarbonyl-4-thianone (1b) followed by deallyloxycarbonylation mediated by tetrakis(triphenylphospine)palladium in the presence of morpholine.The corresponding sulphones 9, as well as 2,3-dialkyl-4-thianone derivatives 12 and 13 can be prepared by analogous procedures.
- Casy, Guy,Sutherland, Alan G.,Taylor, Richard J. K.,Urben, Peter G.
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p. 767 - 769
(2007/10/02)
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- A Regioselective Synthesis of Cyclopentenones from 4-Thianone
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Alkyl-substituted 3-cyclopentenones 4 and 5 were prepared in moderate to good yields starting from 4-thianone by the selective alkylation and Ramberg-Baecklund-type reactions.One route starts with 6-alkyl-1,4-dioxa-8-thiaspirodecane 8,8-dioxides (8) and another with 7-alkyl-1,4-dioxa-7-(p-tolylsulfonyl)-8-thiaspirodecane 8,8-dioxides (15), followed by acid-catalyzed cleavage of the 1,3-dioxolane ring of 1,4-dioxaspironon-7-enes 9 and 16 to afford 4 and 5.
- Matsuyama, Haruo,Miyazawa, Yasuyuki,Takei, Yuji,Kobayashi, Michio
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p. 1703 - 1710
(2007/10/02)
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- Pummerer Rearrangements Using Chlorotrimethylsilane
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Attempted Pummerer rearrangement of 3-methoxycarbonylthian-4-one S-oxide in refluxing acetic anhydride gives unexpected products in which β-carbon oxidation and ring contraction has taken place.Treatment of 3-methoxycarbonylthian-4-one with N-chlorosuccinimide gives similar rearrngement products.These rearrangements are rationalised by the intermediacy of a common thiiranium ion.Chlorotrimethylsilane in refluxing tetrachloromethane efficiently effects the expected Pummerer rearrangement of 3-methoxycarbonylthian-4-one S-oxide into the corresponding α,β-unsaturated sulphides.Reactions of this reagent with related sulphoxides are also described.
- Lane, Simon,Quick, Stephen J.,Taylor, Richard J. K.
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p. 2549 - 2552
(2007/10/02)
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- Epoxyannulation. 4. Reactions of 1,5-, 1,6-, and 1,7-Oxosulfonium Salts
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Treatment of six 1,5- and 1,6-oxosulfonium salts with potassium tert-butoxide affords an oxabicyclohexane, an oxabicycloheptane, hydrindan oxides, or a decalin oxide in 55-95percent yield.The stereoselectivity of this reaction ranges from 75percent for the formation of (1α,3α,7α)-2-oxatricyclo1,3>decane (21) to greater 99percent for (1α,2α,7α)-2-oxatricyclo1,3>decane (14) and for (1α,2α,8β)-2-oxatricyclo1,3>undecane (25).Five 1,7-oxosulfonium salts, one 1,8-salt, and one 1,11-salt and base give only elimination products.The sulfonium salt from 2-cyclopentanone (29) provides 3-methylspirodec-2-en-6-one (30) in 40percent yield.The salt from 2-cyclohexanone (32) yields 38percent of 4-methylbicycloundeca-1(7),3,5-triene (33).
- Garst, Michael E.,McBride, Bill J.,Johnson, Alan T.
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- Enzymes in organic syntheses. 19. Evaluation of the stereoselectivities of horse liver alcohol dehydrogenase; catalyzed oxidoreductions of hydroxy- and ketothiolanes, -thianes, and -thiepanes
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The specificity of horse liver alcohol dehydrogenase (HLADH) with respect to unsubstituted five-, six-, and seven-membered ring 3- and 4-thiaketone and -thiaalcohol substrates has been examined.The enzyme is found to have a broad tolerance of the structural variations within this series.HLADH also exhibits encouraging (up to 46percent) enantiotopic and enantiomeric specifity in preparative-scale reduction and oxidation reactions of the heterocyclic ketones and alcohols respectively.
- Jones, J. Bryan,Schwartz, Harold M.
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p. 1574 - 1579
(2007/10/02)
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- Dissociation Constants of the Cyanohydrins of Some Substituted Thian-4-ones
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The dissociation constants of cyanohydrins of some substituted thian-4-ones and thian-4-one 1,1-dioxides have been determined at 25 deg C in 80percent dioxan.The polymethyl thian-4-one cyanohydrins and r-2,t-6-diiphenyl-c-3-alkylthian-4-ones show increasing instability owing to the effect of axial crowding.
- Nanjappan, Palaniappan,Satyamurthy, Nagichetti,Ramalingam, Kondareddiar
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p. 714 - 716
(2007/10/02)
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