- Mild Deprotection of Dithioacetals by TMSCl/NaI Association in CH3CN
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A mild process using a combination of TMSCl and NaI in acetonitrile is used to regenerate carbonyl compounds from a variety of dithiane and dithiolane derivatives. This easy to handle and inexpensive protocol is also efficient to deprotect oxygenated and mixed acetals as 1,3-dioxanes, 1,3-dioxolanes and 1,3-oxathianes quantitatively. As a possible extension of this method, it was also shown that nitrogenated substrates such as hydrazones, N-tosylhydrazones, and ketimines reacted well under these conditions to give the expected ketones in high yields. The methodology proposed herein is a good alternative to the existing methods since it does not use metals, oxidants, reducing agents, acidic or basic media, and keto-products were obtained in high to excellent yields.
- Yao, Yunxin,Zhao, Guangkuan,Hamze, Abdallah,Alami, Mouad,Provot, Olivier
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p. 5775 - 5779
(2020/08/17)
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- Alcohol-mediated direct dithioacetalization of alkynes with 2-chloro-1,3-dithiane for the synthesis of Markovnikov dithianes
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An alcohol-mediated dithioacetalization process that gains direct access to the corresponding Markovnikov-selective 1,3-dithianes using unactivated alkynes and nonthiolic/odorless 2-chloro-1,3-dithiane in a highly efficient manner has been developed. This methodology has the advantage of having mild reaction conditions, and the dithioacetalization process gives good to excellent yields with high Markovnikov-selectivity.
- Liu, Teng,Tian, Lixia,Lai, Junshan,Min, Deng,Qu, Mengnan,Tang, Shouchu
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supporting information
p. 4068 - 4071
(2017/07/10)
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- A substituted -1,3-dithiane-preparation method of compound
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The invention discloses a method for preparing substituted-1,3-dithiane compounds. The method comprises the following steps: 1. with 1,2-dichloroethane or dichloromethane as a solvent, stirring to react 2-chlor-1,3-dithiane with alkynes with a general formula I for 1-24 hours at a temperature condition of 45-80 DEG C in the presence of an acid medium and alcoholic compounds; 2. removing the solvent in the reaction system by rotary evaporation after the reaction, and separating and purifying the residues by column chromatography to obtain substituted-1,3-dithiane compounds with a general formula II. According to the method disclosed by the invention, the 2-chlor-1,3-dithiane directly reacts with different types of alkynes, thereby not only avoiding the defects of foul smell, strong volatility and toxicity when 1,3-propanedithiol is used, but also being safe in operation and environmental friendly, and the method has the advantages of mild reaction conditions, simple operation, high yield, etc.
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Paragraph 0044-0048
(2017/01/31)
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- SBA-15 functionalized sulfonic acid containing a confined hydrophobic and acidic ionic liquid: A highly efficient catalyst for solvent-free thioacetalization of carbonyl compounds at room temperature
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A novel application of SBA-15 functionalized sulfonic acid containing a confined ionic liquid has been introduced to convert various carbonyl compounds to their corresponding dithioacetals and dithioketals at room temperature and under solvent-free condit
- Karimi, Babak,Vafaeezadeh, Majid
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p. 23207 - 23211
(2013/11/19)
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- Chemoselective dithioacetalization and oxathioacetalization of carbonyl compounds using alumina sulfuric acid as catalyst
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Carbonyl compounds have been successfully converted into their corresponding dithiolane, dithiane, and oxathiolane derivatives using a catalytic amount of alumina sulfuric acid (Al2O3-SO3H) with excellent yields at room temperature in short reaction times under mild conditions. This simple method is a highly chemoselective procedure for protection of aldehydes in the presence of ketones, and the heterogeneous catalyst can be recovered and reused several times without any loss of its activity. Copyright Taylor & Francis Group, LLC.
- Shaterian, Hamid Reza,Hosseinian, Asghar,Ghashang, Majid
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experimental part
p. 4097 - 4106
(2009/04/11)
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- Efficient method for thioacetalization of carbonyl compounds in the presence of a catalytic amount of benzyltriphenylphosphonium tribromide (BTPTB) under solvent-free conditions
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A variety of carbonyl compounds have been successfully converted to the corresponding thioacetal derivatives in good to excellent yields on reaction of carbonyl compounds with 1,2-ethanedithiole, 1,3-propanedithiol, and ethylthiol in the presence of a cat
- Hajipour, Abdol Reza,Pourmousavi, Seied A.,Ruoho, Arnold E.
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p. 2548 - 2566
(2008/12/22)
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- 2,4,4,6-Tetrabromo-2,5-cyclohexadienone (TABCO), N-bromosuccinimide (NBS) and bromine as efficient catalysts for dithioacetalization and oxathioacetalization of carbonyl compounds and transdithioacetalization reactions
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The use of 2,4,4,6-tetrabromo-2,5-cyclohexadienone (TABCO), N-bromosuccinimide (NBS), and bromine as efficient catalysts for conversion of carbonyl compounds to their cyclic and acyclic dithioacetals and 1,3-oxathiolanes under mild reaction conditions are described. These catalysts are also used for efficient transdithioacetalization of acetals, diacetals, ketals, acylals, enamines, hydrazones, and oximes with high yields in the presence of thiols.
- Iranpoor, Nasser,Firouzabadi, Habib,Shaterian, Hamid Reza,Zolfigol
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p. 1047 - 1071
(2007/10/03)
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- 2,3-Dihydro-dithiin and -dithiepine-1,1,4,4-tetroxides: Small molecule non-peptide antagonists of the human galanin hGAL-1 receptor
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The neuropeptide galanin modulates several physiological functions such as cognition, learning, feeding behavior, and depression, probably via the galanin 1 receptor (GAL-R1). Using an HTS assay based on 125I-human galanin binding to the human
- Scott, Malcolm K.,Ross, Tina M.,Lee, Daniel H. S.,Wang, Hoau-Yan,Shank, Richard P.,Wild, Kenneth D.,Davis, Coralie B.,Crooke, Jeffrey J.,Potocki, Alexander C.,Reitz, Allen B.
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p. 1383 - 1391
(2007/10/03)
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- Zirconium tetrachloride (ZrCl4) catalyzed highly chemoselective and efficient transthioacetalization of acetals
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Zirconium tetrachloride (ZrCl4) is an efficient catalyst for the highly chemoselective transthioacetalization of acetals under mild reaction conditions.
- Firouzabadi, Habib,Iranpoor, Nasser,Karimi, Babak
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p. 319 - 320
(2007/10/03)
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- Pyrylium Salt Sensitized Photochemical Deprotections of Dithioacetals and Ketals
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Photoreactions of various dithioacetals and ketals using tris(p-chlorophenyl)pyrylium perchlorate as a sensitizer were studied.Irradiation (λ>360 nm) of dichloromethane solutions containing dithioacetals or ketals and pyrylium salt afforded the corresponding carbonyl compounds in good to excellent yields in the presence of molecular oxygen.
- Kamata, Masaki,Murakami, Yukiko,Tamagawa, Yasuko,Kato, Mitsuaki,Hasegawa, Eietsu
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p. 12821 - 12828
(2007/10/02)
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- Mechanism of the Broensted Acid Catalysed Hydrolysis of 2-Aryl-2-methyl-1,3-dithianes in Aqueous Perchloric acid
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The acid catalysed hydrolysis of five para-substituted 2-aryl-2-methyl-1,3-dithianes in aqueous perchloric acid (3-9 mol dm-3) has been studied kinetically.The effect of changes in substituents (ρ = -3.1), temperature (ΔS(excit.) = -38-60 J K-1 mol-1) and acidity (m(excit.) = 0.54-0.74), and the solvent isotope effects (kobsD2O/kobsH2O E2 mechanism for the MeO, Me, H and Cl derivatives.For the p-NO2 compound the acidity dependence, and the values of ΔH(excit.) and ΔS(excit.) (ca. -200 J K-1 mol-1) suggest a change to an A2-like mechanism.Our results are discussed in the light of previous work on acetal hydrolysis.
- Ali, Muhammad,Satchell, Derek P. N.
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p. 219 - 222
(2007/10/02)
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