- Sulfur-controlled and rhodium-catalyzed formal (3 + 3) transannulation of thioacyl carbenes with alk-2-enals and mechanistic insights
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A rhodium-catalyzed denitrogenative formal (3 + 3) transannulation of 1,2,3-thiadiazoles with alk-2-enals is achieved, producing 2,3-dihydrothiopyran-4-ones in moderate to excellent yields. An inverse KIE of 0.49 is obtained, suggesting the reversibility of the oxidative addition of thioacyl Rh(i) carbenes to alk-2-enals. The late-stage structural modifications of steroid compounds are realized. Moreover, our studies show that thioacyl carbenes have different reactivities to those of α-oxo and α-imino carbenes, and highlight the importance of heteroatoms in deciding the reactivities of heterovinyl carbenes.
- Wu, Qiuyue,Dong, Ziyang,Xu, Jiaxi,Yang, Zhanhui
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supporting information
p. 3173 - 3180
(2021/04/21)
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- Visible-Light Photoredox-Catalyzed Thioacetalization of Aldehydes Under Metal-Free and Solvent-Free Conditions
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A first visible-light photoredox-catalyzed thioacetalization of aldehydes under metal-free and solvent-free conditions is described. Under blue LED irradiation, a reactive thiyl radical was initially generated through single-electron oxidation of thiol, w
- Du, Kai,Wang, Shao-Chien,Basha, R. Sidick,Lee, Chin-Fa
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p. 1597 - 1605
(2018/12/11)
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- Luminescent assays for ketones and aldehydes employing catalytic signal amplification
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Herein we report the first use of transition metal catalytic signal enhancement for the analysis of small organic analytes. Two assays using Sonogashira and Suzuki cross-couplings have been used in the detection of ketones and aldehydes produce highly luminescent markers. The latter analysis utilizing the Suzuki coupling demonstrates the first use of peroxyoxalate initiated chemiluminescence in a sensing application. Chemiluminescent measurement revealed much higher sensitivity than fluorescence. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
- Houk, Ronald J. T.,Anslyn, Eric V.
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p. 729 - 735
(2008/02/12)
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- Perchloric acid adsorbed on silica gel (HClO4-SiO2) as an extremely efficient and reusable catalyst for 1,3-dithiolane/dithiane formation
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Perchloric acid adsorbed on silica gel (HClO4-SiO2) has been found to be an extremely efficient and reusable catalyst for 1,3-dithiolane and 1,3-dithiane formation under solvent-free conditions at room temperature. Georg Thieme Verla
- Rudrawar, Santosh,Besra, Ram C.,Chakraborti, Asit K.
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p. 2767 - 2771
(2008/02/05)
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- Chemoselective dithioacetalization of aldehydes using silica sulfuric acid as a reusable catalyst
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Silica sulfuric acid has been found to be an efficient and reusable catalyst for chemoselective dithioacetalization of aldehydes over ketones, in excellent yields.
- Pore,Desai, Uday V.,Mane,Wadgaonkar
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p. 1291 - 1295
(2007/10/03)
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- A simple and efficient heterogeneous procedure for thioacetalization of aldehydes and ketones
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A new procedure for the protection of aldehydes and ketones as thioacetals promoted by catalytic amount of p-toluene-sulfonic acid and silica gel has been developed. This procedure offers versatility, short reaction time, excellent yield, good selectivity
- Ali, Mohammed Hashmat,Gomes, Maria Goretti
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p. 1326 - 1332
(2007/10/03)
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- Copper(II) tetrafluoroborate as an extremely efficient catalyst for 1,3-dithiolane/dithiane formation from carbonyl compounds under solvent-free conditions at room temperature
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Copper(II) tetrafluoroborate hydrate is a new and extremely efficient catalyst for 1,3-dithiolane/dithiane formation from aromatic, heteroaromatic and aliphatic aldehydes and cyclic saturated ketones in 1-5 min under solvent-free conditions at room temper
- Besra, Ram C.,Rudrawar, Santosh,Chakraborti, Asit K.
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p. 6213 - 6217
(2007/10/03)
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- Scandium Chloride-Catalyzed Chemoselective Thioacetalization of Aldehydes
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A wide variety of acyclic and cyclic dithioacetals can be prepared chemoselectively from the corresponding aldehydes by employing a catalytic amount of scandium chloride in acetonitrile at room temperature.
- De, Surya Kanta
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p. 828 - 830
(2007/10/03)
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- A remarkable bismuth nitrate-catalyzed protection of carbonyl compounds
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Bismuth nitrate has been found to be an outstanding catalyst for the protection of carbonyl compounds as acetal, ketal, mixed ketal and thioketal with an excellent yield.
- Srivastava, Neeta,Dasgupta, Swapan K.,Banik, Bimal K.
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p. 1191 - 1193
(2007/10/03)
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- Trichloroisocyanuric acid, as an industrial chemical, promotes transthioacetalization of diacetals of 2,2-bis (hydroxymethyl)-1,3-propanediol and cleavage of thioacetals
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Trichloroisocyanuric acid has been used as a mild, efficient, and new catalyst for transthioacetalization of diacetals of 2,2-bis (hydroxymethyl)-1,3-propanediol in CH2Cl2 at room temperature. A clean, easy, and general method for efficient deprotection of thioacetals to their corresponding carbonyl compounds using trichloroisocyanuric acid/silica gel and water system also is described.
- Firouzabadi, Habib,Iranpoor, Nasser,Hazarkhani, Hassan
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p. 2571 - 2577
(2007/10/03)
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- Dehydration reactions in water. Surfactant-type bronsted acid-catalyzed dehydrative etherification, thioetherification, and dithioacetalization in water
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Dehydration reactions such as etherification, thioetherification, and dithioacetalization are efficiently catalyzed by a surfactant-type Bronsted acid in water.
- Kobayashi, Shu,Iimura, Shinya,Manabe, Kei
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- Indium triflate: A mild Lewis acid catalyst for thioacetalization and transthioacetalization
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Protection of a variety of carbonyl compounds as thioacetals using indium triflate, a mild Lewis acid catalyst, was achieved at ambient temperature in very good yield. Transthioacetalization of oxyacetals into thioacetals was also achieved in an excellent
- Muthusamy, Sengodagounder,Arulananda Babu, Srinivasarao,Gunanathan, Chidambaram
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p. 7897 - 7901
(2007/10/03)
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- Dehydration reactions in water. Bronsted acid-surfactant-combined catalyst for ester, ether, thioether, and dithioacetal formation in water
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Dehydration reactions in water have been realized by a surfactant-type catalyst, dodecylbenzenesulfonic acid (DBSA). These reactions include dehydrative esterification, etherification, thioetherification, and dithioacetalization. In these reactions, DBSA and substrates form emulsion droplets whose interior is hydrophobic enough to exclude water molecules generated during the reactions. Detailed studies on the esterification revealed that the yields of esters were affected by temperature, amounts of DBSA used, and the substrates. Esters were obtained in high yields for highly hydrophobic substrates. On the basis of the difference in hydrophobicity of the substrates, unique selective esterification and etherification in water were attained. Furthermore, chemospecific, three-component reactions under DBSA-catalyzed conditions were also found to proceed smoothly. This work not only may lead to environmentally benign systems but also will provide a new aspect of organic chemistry in water.
- Manabe, Kei,Iimura, Shinya,Sun, Xiang-Min,Kobayashi, Shu
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p. 11971 - 11978
(2007/10/03)
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- Highly efficient transthioacetalization of O,O-acetals catalyzed by indium(III) chloride
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A simple, efficient and general procedure has been developed for the transthioacetalization of O,O-acetals catalyzed by indium(III) chloride in 1,2-dichloroethane.
- Ranu, Brindaban C.,Das, Arijit,Samanta, Sampak
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p. 727 - 730
(2007/10/03)
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- Catalysis by ionic liquids: Solvent-free efficient transthioacetalisation of acetals by molten tetrabutylammonium bromide
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Transthioacetalisation of acetals to dithioacetals by a solvent-free reaction with a thiol or dithiol catalyzed by molten tetrabutylammonium bromide was presented. Acetals were prepared by standard methods and were purified by distillation or chromatography. Tetrabutylammonium bromide in molten state was demonstrated to be an efficient and recyclable catalyst. The methodology offered improvements over other procedures in relation to yield of products, selectivity for acetal of aldehyde over that of ketone, and mildness of reaction conditions.
- Ranu, Brindaban C.,Das, Arijit,Samanta, Sampak
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p. 1520 - 1522
(2007/10/03)
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- Highly efficient dithioacetalization of carbonyl compounds catalyzed with iodine supported on neutral alumina
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Aldehydes and ketones are protected as their corresponding dithioacetals with ethane-1,2-dithiol in the presence of a catalytic amount of iodine supported on neutral alumina surface. This is a high yielding method of carbonyl group protection under mild,
- Deka, Nabajyoti,Sarma, Jadab C.
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p. 794 - 795
(2007/10/03)
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- Solvent free thioacetalization of carbonyl compounds catalyzed by Cu(OTf)2-SiO2
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Aldehydes and ketones were thioacetalyzed using 1,2-ethanedithiol in the presence of a catalytic amount of Cu(OTf)2-SiO2 under solvent free conditions in excellent yields.
- Anand, R. Vijaya,Saravanan,Singh, Vinod K.
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p. 415 - 416
(2007/10/03)
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- Transdithioacetalization of acetals, ketals, oximes, enamines and tosylhydrazones catalysed by natural kaolinitic clay
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Natural kaolinitic clay efficiently catalyses the transdithioacetalization of acetals, ketals, oximes, enamines and tosylhydrazones with ethane-1,2-dithiol and propane-1,3-dithiol to produce the corresponding dithiolanes in high yields.
- Jnaneshwara,Barhate,Sudalai,Deshpande,Wakharkar,Gajare,Shingare,Sukumar
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p. 965 - 968
(2007/10/03)
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- Selective Transdithioacetalization of Acetals, Ketals, Oxathioacetals and Oxathioketals Catalyzed by Envirocat EPZ10 R
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Envirocat EPZ10R has been found to be a remarkable reusable heterogeneous catalyst for selective transdithioacetalization of acetals, ketals, oxathioacetals and oxathioketals with HSCH2CH2SH and HSCH2CH2/s
- Gajare,Shingare,Bandgar
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p. 452 - 453
(2007/10/03)
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- Direct synthesis of dithioketals from N,N-dialkylhydrazones
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Direct dithioketalisation of N,N-dialkylhydrazones promoted by BF3·Et2O or p-TsOH and 1,2-ethanedithiol in dry medium affords the corresponding dithiolanes in nearly quantitative yields. A variety of hydrazones derived from several k
- Diez, Elena,Lopez, Ana M.,Pareja, Carmen,Martin, Eloisa,Fernandez, Rosario,Lassaletta, Jose M.
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p. 7955 - 7958
(2007/10/03)
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- Zirconium(IV) chloride-silica catalysed thioacetalisation of carbonyl compounds
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Anhydrous anhydrous zirconium(IV) chloride dispersed on silica gel efficiently thioacetalised a variety of carbonyl compounds in near quantitative yields.
- Patney, Harish K.,Margan, Simon
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p. 4621 - 4622
(2007/10/03)
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- A Study of 2-Propenethials Obtained by Flash Vacuum Pyrolysis of 2-Ethenyl-1,3-dithiolane 1,1-Dioxides
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Synthesis of substituted 2-propenethials by the flash vacuum pyrolysis of appropriately substituted 2-ethenyl-1,3-dithiolane 1,1-dioxides has been investigated.Pyrolysis of 2-propenyl-1,3-dithiolane 1,1-dioxide (5a) gives thiophene, 2,5-dihydrothiophene, a dimer (11) and dimer (12) of 2-butenethial (4a).Pyrolysis of 2-(1-methylpropenyl)-1,3-dithiolane 1,1-dioxide (5b) gives 3-methylthiophene and a trimer (14) of 2-methyl-2-butenethial (4b).Pyrolysis of 2-(2-phenylethenyl)-1,3-dithiolane 1,1-dioxide (5c) gives 2H-1-benzothiin (15) and a dimer (16) of 3-phenyl-2-propenethial (4c).The dimer (11), 2-propenyl-4-methyl-4H-1,3-dithiin, can be considered as the meta-substituted cycloaddition product of 2-butenethial, whereas the dimer (16), 3-(2-phenylethenyl)-4-phenyl-3,4-dihydro-1,2-dithiin, can be considered as the ortho-substituted cycloaddition product of 2-phenyl-2-propenethial.
- Liao, Li-Fan,Tseng, Pen-Wen,Chou, Chin-Hsing,Chou, Wen-Chih,Fang, Jim-Min
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p. 1967 - 1978
(2007/10/02)
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- A rapid mild and efficient method of thioacetalization using anhydrous iron(III) chloride dispersed on silica gel
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Carbonyl compounds are rapidly thioacetalized in near quantitative yields by using anhydrous iron(III) chloride dispersed on silica gel at room temperature.
- Patney
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p. 2259 - 2260
(2007/10/02)
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- TETRACHLOROSILANE CATALYZED DITHIOACETALIZATION
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Tetrachlorosilane was found to be a mild as well as selective catalyst for dithioacetalization of the carbonyl compounds.
- Ku, Bonchul,Oh, Dong Young
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p. 433 - 438
(2007/10/02)
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- Reactions of 1,3-Dithiolan-2-ylium and 1,3-Dithian-2-ylium Tetrafluoroborates and Ambident 2-Styryl Derivatives
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The ambident 2-styryl-1,3-dithiolan-2-ylium and 2-styryl-1,3-dithian-2-ylium cations react with preferential carbon-carbon bond formation at the β ethylenic carbon when treated with methylmagnesium iodide.In the lithium aluminium hydride reaction, reduction occurs at either electrophilic carbon center.Methanol and thiophenol react selectively with the β carbon of the side chain.The adduct formation with the heteroatom nucleophiles is readily reversed by acid catalysis.In the absence of the styryl group, the nucleophilic addition is at C-2.Dithioketals of symmetric 1,2-divarbonyl derivatives are readily formed by zinc-induced reductive dimerization of 1,3-dithiolan- and 1,3-dithian-2-ylium salts.
- Klaveness, Jo,Rise, Frode,Undheim, Kjell
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p. 373 - 380
(2007/10/02)
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- Lewis Acid Mediated Reaction of Trimethylstyrylsilanes with Thioacetal Derivatives
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Treatment of trimethylstyrylsilanes with 1-ethoxy-1-(phenylthio)ethane or 2-ethoxy-1,3-dithiolane in the presence of Lewis acid gives the corresponding (E)-allyl sulfide or (E)-2-styryl-1,3-dithiolane, respectively.In both cases, a carbon-oxygen bond of t
- Hirao, Toshikazu,Kohno, Shuichiro,Ohshiro, Yoshiki,Agawa, Toshio
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p. 1569 - 1570
(2007/10/02)
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