- Ethyl lactate mediated thioacetalization of aldehydes at ambient temperature
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Dithioacetalization reactions of aldehydes with thiols/thiophenols have been successfully achieved at room temperature by employing the green, bio-based ethyl lactate as the reaction medium. By means of this sustainable approach, a class of dithioacetals has been acquired with high diversity and efficiency.
- Wan, Jie-Ping,Jing, Yanfeng,Liu, Yunyun
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p. 1302 - 1305
(2016/09/28)
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- Silica-supported phosphorus pentoxide: A reusable catalyst for S,S-acetalization of carbonyl groups under ambient conditions
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Phosphorus pentoxide supported on silica gel (P2O 5/SiO2) efficiently acts as a highly active and reusable catalyst for cyclic and non-cyclic S,S-acetalization of a variety of carbonyl compounds under mild, solvent-free an
- Shaterian, Hamid Reza,Azizi, Kobra,Fahimi, Nafiseh
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experimental part
p. 85 - 91
(2012/01/06)
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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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- An efficient method for thioacetalization of carbonyl compounds in the presence of a catalytic amount of benzyltriphenylphosphonium tribromide 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 the reaction of carbonyl compounds with 1,2-ethanedithiole, 1,3-propanedithiol, and ethanethiol in the presence of
- Hajipour, Abdol R.,Pourmousavi, Seied A.,Ruoho, Arnold E.
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p. 921 - 937
(2008/02/05)
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- Simple, mild and efficient thioacetalization and transthioacetalization of carbonyl compounds and deprotection of thioacetals: Unique role of thiols in the selectivity of thioacetalization
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Silica supported sodium hydrogen sulfate (NaHSO4·SiO 2) has been employed for efficient thioacetalization and transthioacetalization of carbonyl compounds in CH2Cl2 at room temperature. Selectivity of thioacetalization was dependent on the thiols used for the conversion. The same catalyst was also found to be effective for deprotection of thioacetals in CH2Cl2-H2O at room temperature.
- Das, Biswanath,Ramu, Ravirala,Reddy, Majjigapu Ravinder,Mahender, Gurram
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p. 250 - 254
(2007/10/03)
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- Proton Transfer from Carbon. A Study of the Acid-Base-catalysed Relaxation and the Bromination of Aryl-substituted Methanedisulfones
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Seven aryl-substituted derivatives of bis(ethylsulfonyl)methane have been synthesized and studied thermodynamically and kinetically in aqueous solution with respect to proton abstraction from the central carbon atom.The acidities of the six carbon acids are in the range pKA 10-12.The relaxation times of the reactions were studied by a spectrophotometric temperature-jump technique (hydroxide ion and phenolates as proton acceptors) and are in the microsecond range.The rates of bromination of the various carbanions have also been studied (potentiometrically) and the reactions are shown to be almost diffusion-controlled, with no marked trend with aromatic substituent.A small chemical activation may be due to a steric effect by the two sulfonyl groups.The rates of deprotonation, however, show considerable chemical activation, i.e., intrinsic rates are 3-4 orders of magnitude lower than for normal acids, indicating partial delocalization of the negative charge on the carbanion.This effect is somewhat larger than for cyano-activated carbon acids but considerably smaller than for carbon acids activated by carbonyl or nitro groups.It is concluded that sulfonyl groups interact with carbanions primarily by polar effects, but also, to some extent, mesomerically.The degree of mesomerism is, however, uncertain because part of the intrinsic barrier may derive from steric effects, as is also observed for bromination.
- Aiken, Fiona,Cox, Brian G.,Soerensen, Poul E.
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p. 783 - 790
(2007/10/02)
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