- Ruthenium(III) chloride-catalyzed thioacetalization of carbonyl compounds: Scope, selectivity, and limitations
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A variety of carbonyl compounds can be easily and rapidly converted to the corresponding cyclic and acylic dithioacetals in the presence of a catalytic amount of ruthenium chloride in acetonitrile at room temperature. Some of the major advantages of this
- De, Surya Kanta
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- Phosphorylated Polyacrylonitrile Fibers as an Efficient and Greener Acetalization Catalyst
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A novel solid acid catalyst (PANEAPF) is developed by immobilization of phosphoric acid on polyacrylonitrile fiber through covalent bonding. Various characterization techniques such as elemental analysis (EA), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), etc. are utilized to confirm the successful grafting and the stability of the fiber catalysts during application. PANEAPF shows high catalytic activity in the acetalization of aldehydes owing to the high utilization efficiency of its functionalized acid sites. In addition, the strong polarity micro-environment in the surface layers of PANEAPF make it highly suitable for catalytic application in both water and alcohol. Furthermore, the fiber catalyst can be applied to the acetalization of aldehydes in a continuous-flow process at room temperature, and shows excellent reactivity and superior recyclability (over 20 times). The many advantages of PANEAPF such as simple preparation, convenient regulation of acid amount, high durability, and eco-friendly process make it very attractive for fixed-bed reactors in the chemical industry.
- Xu, Gang,Cao, Jian,Zhao, Yali,Zheng, Lishuo,Tao, Minli,Zhang, Wenqin
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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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- Chemoselective thioacetalisation and transthioacetalisation of carbonyl compounds catalysed by tetrabutylammonium tribromide (TBATB)
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Thioacetals and thioketals of various aldehydes and ketones were obtained directly from carbonyl compounds or by a transthioacetalisation process from cyclic O,O-acetals in the presence of dithiols and a catalytic amount of tetrabutylammonium tribromide (TBATB). Chemoselective thioacetalisation of aromatic aldehydes containing an electron-donating group in the presence of an aldehyde containing an electron-withdrawing group, aldehydes in the presence of ketones, aliphatic cyclic ketones in the presence of aromatic ketones and less hindered ketones in the presence of more hindered ketones have been achieved. A cyclic acetal containing an electron-donating group has been chemoselectively transthioacetalised in the presence of an acetal having an electron-withdrawing substituent. These selectivities are due to the intrinsic reactivity of the substrate themselves and are independent of the catalyst and reaction conditions, Shorter reaction times, mild reaction conditions, stability of acid sensitive protecting groups, high efficiencies, facile isolation of the desired products and the catalytic nature of the reagent are the attractive features of the present method.
- Naik, Sarala,Gopinath, Rangam,Goswami, Mousumi,Patel, Bhisma K.
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- Sulfonated polyanthracene-catalyzed highly efficient and chemoselective thioacetalization of carbonyl compounds and transthioacetalization of acetals and acylals
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A straightforward and highly efficient procedure for the thioacetalization of a variety of aldehydes and transthioacetalization of acylals and acetals in good to excellent yields using catalytic amounts of sulfonated polyanthracene (S-PAT) is reported. Th
- Fahid,Pourmousavi
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- Oxathioacetalization, thioacetalization and transthioacetalization of carbonyl compounds by N-bromosuccinimide: Selectivity and scope
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Efficient oxathioacetalization, thioacetalization and transthioacetalization of carbonyl compounds have been achieved in high yields employing N-bromosuccinimide as a catalyst.
- Kamal, Ahmed,Chouhan, Gagan,Ahmed, Kaleem
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- Aluminum hydrogen sulfate [Al(HSO4)3] as an efficient catalyst for the preparation of thioacetals
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Aluminum hydrogen sulfate, as a heterogeneous solid acid catalyst, has been used for the mild conversion of carbonyl compounds to their thioacetals using 1,2- and 1,3-dithiol under ambient conditions with short reaction times in high to excellent yield in
- Ghashang, Majid
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- Highly efficient and chemoselective method for the thioacetalization of aldehydes and transthioacetalization of acetals and acylals catalyzed by H 2SO4-silica under solvent-free conditions
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Chemoselective and efficient thioacetalization of a variety of aldehydes was achieved in excellent yields at room temperature using 1,2-ethanedithiol in the presence of catalytic amounts of H2SO4-silica. Thioacetals were also prepare
- Pourmousavi, Seied Ali,Kazemi, Shaghayegh Sadat
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experimental part
p. 917 - 923
(2012/07/16)
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- An efficient method for the transthioacetalization of acylals and acetals under mild conditions
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A rapid and efficient method for the transthioacetalization of acylals (1,1-diacetates) and acyclic and cyclic acetals is described. The reaction was carried out using 1-benzyl-4-aza-1-azoniabicyclo[2.2.2]octane tribromide (1 mol%). The yield of the transthioacetalization was high and reaction conditions involve the use of acetonitrile as the solvent at room temperature; isolation is simple and the products are nearly pure.
- Pourmousavi, Seied Ali,Hadavankhani, Majid,Zinati, Zahra
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experimental part
p. S495-S501
(2012/05/31)
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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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- Selective Protection of Carbonyl Compounds. Silica Gel Treated with Thionyl Chloride as an Effective Catalyst for Thioacetalization
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Silica gel treated with thionyl chloride was found to be an effective as well as highly selective catalyst for thioacetalization of aldehydes.With the use of this catalyst 1,3-dithioranes and 1,3-dithianes were obtained in excellent yields from various aldehydes.Under the same conditions ketones were similarly but more slowly thioketalized.This difference in reactivity between aldehydes and ketones was successfully utilized for the thioacetalization of aldehydes in the presence of ketones and also for the chemoselective conversion of keto aldehydes into the corresponding dithioacetals with the keto group remaining intact.
- Kamitori, Yasuhiro,Hojo, Masaru,Masuda, Ryoichi,Kimura, Tadashi,Yoshida, Tatsushi
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p. 1427 - 1431
(2007/10/02)
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