- Crystallinity after decarboxylation of a metal-carboxylate framework: indestructible porosity for catalysis
-
We report a curious case study of a Zr(iv)-carboxylate framework, which retains significant crystalline order after cascade thermocyclization of its linker components, and - more notably - after the crucial carboxylate links were severed by heat. Vigorous heat treatment (e.g., 450 °C and above) benzannulates the multiple alkyne groups on the linker to generate linked nanographene blocks and to afford real stability. The resultant Zr oxide/nanographene hybrid solid is stable in saturated NaOH and concentrated H3PO4, allowing a convenient anchoring of H3PO4into its porous matrix to enable size-selective heterogeneous acid catalysis. The Zr oxide components can also be removed by strong hydrofluoric acid to further enhance the surface area (up to 650 m2g?1), without collapsing the nanographene scaffold. The crystallinity order and the extensive thermal transformations were characterized by X-ray diffraction, scanning transmission electron microscopy (STEM), IR, solid state NMR and other instrumental methods.
- Cheng, Shengxian,Feng, Weijin,Gao, Wenpei,He, Jun,Hu, Jieying,Pan, Xiaoqing,Tieu, Peter,Xu, Zhengtao
-
p. 11902 - 11910
(2020/09/21)
-
- Mesoporous sBa-15 silica catalyst functionalized with phenylsulfonic acid groups (SbA-15-ph-So3h) as efficient nanocatalyst for chemoselective thioacetalization of carbonyl compounds
-
In this research a Nano acidic catalyst was prepared and its efficiency on thioacetalization of carbonyl compounds was examined. For this aim we used modified SBA-15 as support, which have been modified by phenolic and sulfonic acid. SBA-15 is a member of
- Sedrpoushan, Alireza,Ghazizadeh, Habibollah
-
p. 112 - 118
(2017/01/18)
-
- Sulfonated polyanthracene-catalyzed highly efficient and chemoselective thioacetalization of carbonyl compounds and transthioacetalization of acetals and acylals
-
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
-
-
- Selective arylthiolane deprotection by singlet oxygen: A promising tool for sensors and prodrugs
-
A routine thioketal protecting group reacts rapidly and selectively with singlet oxygen to reveal ketone products in good (aryl 1,3-dithiolane) to excellent (aryl 1,3-oxathiolane) yields. Arylthiolanes are stable to biologically relevant reactive oxygen species and can be used as a light-activated gating mechanism for activating fluorescent sensors or small molecule prodrugs.
- Lamb, Brian M.,Barbas, Carlos F.
-
supporting information
p. 3196 - 3199
(2015/05/27)
-
- Efficient thioacetalisation of carbonyl compounds
-
The thioacetalisation of a variety of heterocyclic, aromatic, and aliphatic carbonyl compounds (1 mmol) with ethane-1,2-dithiol (1 mmol) using silica sulphuric acid (SSA) is presented as an efficient heterogeneous catalyst under mild and solvent-free cond
- Habibi, Davood,Rahmani, Payam,Akbaripanah, Ziba
-
p. 417 - 421
(2014/01/06)
-
- Facile protection of carbonyl compounds as oxathiolanes and thioacetals promoted by PEG1000-based dicationic acidic ionic liquid as chemoselective and recyclable catalyst
-
Efficient oxathioacetalization and thioacetalization of carbonyl compounds have been achieved in high yields employing PEG1000-based dicationic acidic ionic liquid as a catalyst. The PEG ionic liquid and toluene have the advantages of both homo
- Ren, Yi-Ming,Shao, Juan-Juan,Wu, Zhi-Chuan,Zhang, Shuai,Tao, Ting-Xian
-
p. 392 - 394
(2014/06/09)
-
- Silica-gel supported sulfamic acid (SA/SiO2) as an efficient and reusable catalyst for conversion of ketones into oxathioacetals and dithioacetals
-
A simple and efficient method for the conversion of carbonyl compounds to oxathioacetals and dithioacetals using SA/SiO2 as an acid catalyst has been achieved. SA/SiO2 is easily recovered from the reaction mixture and can be reused at least 15 times without loss of catalytic activity.
- Aoyama, Tadashi,Suzuki, Toshihiko,Nagaoka, Takashi,Takido, Toshio,Kodomari, Mitsuo
-
p. 553 - 566
(2013/01/15)
-
- Silica phenyl sulfonic acid as a solid acid heterogeneous catalyst for chemoselective thioacetalization of carbonyl compounds and dethioacetalization under mild conditions
-
Silica phenyl sulfonic acid (SPSA) is an effective catalyst for chemoselective thioacetalization of aldehydes in the presence of ketones under neutral conditions. In addition, a simple and an efficient procedure for deprotection of 1,3-dithianes and 1,3-dithiolanes of aromatic, aliphatic, and α,β-unsaturated aldehydes and ketones in the solvent-free to the corresponding parent carbonyl compounds was successfully carried out with SPSA in excellent yields.
- Veisi, Hojat,Sedrpoushan, Alireza,Zolfigol, Mohammad Ali,Mohanazadeh, Farajollah,Hemmati, Saba
-
p. E204-E206
(2013/06/04)
-
- Synthesis of 1,3-dithiane and 1,3-dithiolane derivatives by tungstate sulfuric acid: Recyclable and green catalyst
-
An efficient, novel, and environmentally benign procedure for the thioacetalization of aliphatic and aromatic carbonyl compounds in the presence of catalytic amounts of tungstate sulfuric acid under solvent-free conditions to afford 1,3-dithianes and 1,3-
- Karami, Bahador,Taei, Mahbubeh,Khodabakhshi, Saeed,Jamshidi, Masih
-
experimental part
p. 65 - 74
(2012/07/14)
-
- Poly(N-bromobenzene-1,3-disulfonamide) and N,N,N′,N′- tetrabromobenzene-1,3-disulfonamide as a mild and efficient catalyst for chemoselective thioacetalization of carbonyl functions and transthioacetalization reactions
-
Poly(N-bromobenzene-1,3-disulfonamide) and N,N,N′,N′- tetrabromobenzene-1,3-disulfonamide are effective catalysts for chemoselective dithioacetalization of aldehydes in the presence of ketones under neutral conditions.
- Veisi, Hojat,Ghorbani-Vaghei, Ramin,Dadamahaleh, Somayeh Akbari
-
experimental part
p. 699 - 705
(2011/07/31)
-
- Silica-supported phosphorus pentoxide: A reusable catalyst for S,S-acetalization of carbonyl groups under ambient conditions
-
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
-
experimental part
p. 85 - 91
(2012/01/06)
-
- Thioacetalization of aldehydes and ketones in SDS micelles
-
Aromatic aldehydes have been successfully converted into their corresponding dithioacetal, dithiolane and dithiane derivatives in excellent yields with thiol (benzyl thiol and thiophenol), 1,2-ethanedithiol and 1,3-propanedithiol using trichloroacetic acid in sodium dodecyl sulfate micelles. The same procedure is applicable to ketones, but they need more time to be converted into their thioacetals. Image Presented.
- Bahrami, Kiumars,Khodaei, Mohammad Mehdi,Tajik, Maryam,Soheilizad, Mehdi
-
experimental part
p. 397 - 403
(2012/06/18)
-
- Green, catalyst-free thioacetalization of carbonyl compounds using glycerol as recyclable solvent
-
We describe herein the use of glycerol as an efficient and a recyclable solvent in the thioacetalization of aldehydes and ketones. The catalyst-free reactions proceed easily using glycerol at 90 °C and the corresponding thioacetals were obtained in good to excellent yields. Glycerol was recovered and utilized for further thioacetalization reactions.
- Perin, Gelson,Mello, Luzia G.,Radatz, Cátia S.,Savegnago, Lucielli,Alves, Diego,Jacob, Raquel G.,Lenard?o, Eder J.
-
experimental part
p. 4354 - 4356
(2010/09/12)
-
- 1,3-dibromo-5,5-dimethylhydantoin (DBH) as a mild and efficient catalyst for chemoselective thioacetalization of carbonyl compounds and dethioacetalization under mild conditions
-
Hydantoin bromide is an effective catalyst for chemoselective thioacetalization of aldehydes in the presence of ketones under neutral conditions. In addition, a simple and efficient procedure for the deprotection of 1,3-dithianes and 1,3-dithiolanes of ar
- Veisi, Hojat,Amiri, Mostafa,Hamidian, Amir Hossein,Malakootikhah, Javad,Fatolahi, Leila,Faraji, Alireza,Sedrpoushan, Alireza,Maleki, Behrooz,Saremi, Shokufe Ghahri,Noroozi, Mohammad,Bahadoori, Fatemeh,Veisi, Somayeh
-
experimental part
p. 689 - 696
(2010/06/19)
-
- Silica-PCl5: A novel heterogenous catalyst for simple and efficient chemoselective protection of carbonyl compounds
-
A simple, efficient and environmentally benign procedure has been developed for chemoselective protection of carbonyl compounds using the newly developed heterogeneous catalyst: Silica-PCl5. A variety of aldehydes and ketones were efficiently c
- Pandey, Lokesh Kumar,Pathak, Uma,Tank, Rekha,Mazumder, Avik
-
experimental part
p. 167 - 171
(2010/07/05)
-
- Catalytic carbon-sulfur bond formation by amphoteric vanadyl triflate: exploring with thia-Michael addition, thioacetalization, and transthioacetalization reactions
-
A series of thiols have been examined as protic nucleophiles for Michael-type additions to α,β-unsaturated carbonyls as well as double nucleophilic condensations with aldehydes, ketones, and acetals catalyzed by amphoteric, water-tolerant vanadyl triflate under mild and neutral conditions. The newly developed C-S bond formation protocols were carried out smoothly in good to high yields in a highly chemoselective manner.
- Chen, Chien-Tien,Lin, Yow-Dzer,Liu, Cheng-Yuan
-
supporting information; experimental part
p. 10470 - 10476
(2010/02/28)
-
- Efficient method for thioacetalization of carbonyl compounds in the presence of a catalytic amount of benzyltriphenylphosphonium tribromide (BTPTB) under solvent-free conditions
-
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.
-
p. 2548 - 2566
(2008/12/22)
-
- Chemoselective dithioacetalization and oxathioacetalization of carbonyl compounds using alumina sulfuric acid as catalyst
-
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
-
experimental part
p. 4097 - 4106
(2009/04/11)
-
- Application of BU4N+HSO4- as an ionic liquid and acid catalyst for thioacetalization of aldehydes and ketones
-
A variety of carbonyl containing compounds have been successfully reacted with 1,2-ethanedithiol in a thioacetylization reaction using tetrabutylammonium hydrogensulfate as a mild and efficient catalyst. Aldehydes and ketones react with good to excellent
- Hajipour, Abdol R.,Hosseini, Peyman,Ruoho, Arnold E.
-
experimental part
p. 2502 - 2508
(2009/08/07)
-
- Regioselective transformation of alkynes into cyclic acetals and thioacetals with a gold(I) catalyst: comparison with Br?nsted acid catalysts
-
Au(I) catalyzes the transformation of alkynes into cyclic acetals and thioacetals at much higher rate than Br?nsted acids. The reaction appears to be general for a range of alkynes and diols or dithiols, which are efficiently transformed with high selectivities. One of the salient features of this reaction process is the high reactivity of the enol ether or enol thioether intermediates, which undergo a rapid isomerization reaction to afford the cyclic acetals or thioacetals, so that isolation or subsequent activation processes are not required. This type of reactions allows us to synthesize a series of fragrances.
- Santos, Laura L.,Ruiz, Violeta R.,Sabater, Maria J.,Corma, Avelino
-
p. 7902 - 7909
(2008/12/21)
-
- An efficient, continuous flow technique for the chemoselective synthesis of thioacetals
-
By optimizing a reagent's residence time within a packed-bed reactor, it is possible to overcome selectivity issues frequently encountered in stirred reaction vessels. This important feature is demonstrated for the chemoselective protection of 4-acetylben
- Wiles, Charlotte,Watts, Paul,Haswell, Stephen J.
-
p. 7362 - 7365
(2008/03/13)
-
- An efficient method for thioacetalization of carbonyl compounds in the presence of a catalytic amount of benzyltriphenylphosphonium tribromide under solvent-free conditions
-
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.
-
p. 921 - 937
(2008/02/05)
-
- Perchloric acid adsorbed on silica gel (HClO4-SiO2) as an extremely efficient and reusable catalyst for 1,3-dithiolane/dithiane formation
-
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.
-
p. 2767 - 2771
(2008/02/05)
-
- Chemoselective dithioacetalization of aldehydes using silica sulfuric acid as a reusable catalyst
-
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
-
p. 1291 - 1295
(2007/10/03)
-
- A rapid and efficient method for 1,3-dithiolane synthesis
-
A mild, efficient and solvent-free protocol for conversion of aldehydes and ketones into their corresponding 1,3-dithiolanes using 1,2-ethanedithiol in the presence of a catalytic amount of SnCl2·2H2O is reported.
- Bez, Ghanashyam,Gogoi, Dipankoj
-
p. 5155 - 5157
(2007/10/03)
-
- A mild and chemoselective catalyst for thioacetalization under solvent free conditions
-
Protection of a variety of carbonyl compounds as dithioacetals using P 2O5/SiO2 (75%), as a mild and chemoselective catalyst, was achieved under solvent free conditions in very good yields. Copyright Taylor & Francis Group
- Hajipour, Abdol R.,Zarei, Amin,Khazdooz, Leila,Zahmatkesh, Saeed,Ruoho, Arnold E.
-
p. 387 - 395
(2007/10/03)
-
- A simple and efficient heterogeneous procedure for thioacetalization of aldehydes and ketones
-
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
-
p. 1326 - 1332
(2007/10/03)
-
- A simple and practical synthetic protocol for thioacetalization of carbonyl compounds
-
Various aldehydes and ketones are smoothly converted to the corresponding acyclic and cyclic dithioacetals in very good yields by employing catalytic amount of acetyl chloride at room temperature under solvent-free conditions. Some of the major advantages of this procedure are its mild reaction conditions, highly efficient and selective, good yields, economically cheaper and compatible in the presence of a wide variety of other protecting groups.
- Khan, Abu T.,Mondal, Ejabul
-
p. 844 - 850
(2007/10/03)
-
- Copper(II) tetrafluoroborate as an extremely efficient catalyst for 1,3-dithiolane/dithiane formation from carbonyl compounds under solvent-free conditions at room temperature
-
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.
-
p. 6213 - 6217
(2007/10/03)
-
- Ruthenium(III) chloride-catalyzed thioacetalization of carbonyl compounds: Scope, selectivity, and limitations
-
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
-
p. 673 - 676
(2007/10/03)
-
- A simple and practical synthetic protocol for acetalisation, thioacetalisation and transthioacetalisation of carbonyl compounds under solvent-free conditions
-
A wide variety of carbonyl compounds can be converted smoothly to the corresponding acetals on treatment with alcohols or diols and triethyl orthoformate in the presence of a catalytic amount of (bromodimethyl)sulfonium bromide at room temperature. Similarly, various carbonyl compounds can be transformed into the corresponding dithioacetals on reaction with thiol or dithiols at room temperature by employing the same catalyst without any solvent. Moreover, O,O-acetals can also be converted into the corresponding dithioacetals under identical conditions. Some of the major advantages are mild reaction conditions, a high degree of efficiency, compatibilty with other protecting groups and the lack of solvents, particularly for thioacetalisation. In addition, no brominations occur at the double bond or α to the keto position or even in the aromatic ring under these experimental conditions. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Khan, Abu T.,Mondal, Ejabul,Ghosh, Subrata,Islam, Samimul
-
p. 2002 - 2009
(2007/10/03)
-
- Chemoselective thioacetalisation and transthioacetalisation of carbonyl compounds catalysed by tetrabutylammonium tribromide (TBATB)
-
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.
-
p. 1670 - 1677
(2007/10/03)
-
- Superoxide induced deprotection of 1,3-dithiolanes: A convenient method of dedithioacetalization
-
Tetraethylammonium superoxide, generated in situ by the phase transfer reaction of potassium superoxide and tetra-ethylammonium bromide, brings about an easy deprotection of a variety of 1,3-dithiolanes of carbonyl compounds under significantly mild reaction conditions at room temperature.
- Shukla, Ajay Kumar,Verma, Manjusha,Singh, Krishna Nand
-
p. 1748 - 1752
(2007/10/03)
-
- α,α-diacetyl cyclic ketene dithioacetals: Odorless and efficient dithiol equivalents in thioacetalization reactions
-
Two novel, non-thiolic, odorless dithiol equivalents, α,α- diacetyl cyclic ketene dithioacetals 2a and 2b, had been developed. A range of carbonyl compounds 3 were converted into corresponding dithioacetals, dithianes 4 and dithiolanes 5, in high yields (up to 99%) in the presence of 2a or 2b. Moreover, 2a and 2b show high chemoselectivity between aldehyde and ketone in thioacetalization.
- Yu, Haifeng,Liu, Qun,Yin, Yanbing,Fang, Qunxin,Zhang, Jingping,Dong, Dewen
-
p. 999 - 1002
(2007/10/03)
-
- Chemoselective Protection of Carbonyl Compounds as Dithioacetals Using Silica Gel Supported Aluminium Chloride
-
Silica gel supported aluminium chloride is shown to be a mild chemoselective catalyst for dithioacetalization of carbonyl compounds.
- Tamami,Borujeny, K. Parvanak
-
p. 4253 - 4258
(2007/10/03)
-
- 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
-
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
-
p. 1047 - 1071
(2007/10/03)
-
- Highly efficient transthioacetalization of O,O-acetals catalyzed by indium(III) chloride
-
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
-
p. 727 - 730
(2007/10/03)
-
- Heteropoly acids as heterogeneous catalysts for thioacetalization and transthioacetalization reactions
-
Heteropoly acids are effective solid catalysts for the thioacetalization of carbonyl compounds. Tungstophosphoric acid (H3PW12O40), was found to be an effective and a highly selective catalyst for the thioacetalization of aldehydes, ketones and for the transthioacetalization of acetals, acylals and O,S-acetals which proceeded in excellent yields in the absence of solvent. The catalyst has also been successfully applied to the chemoselective conversion of α- or β-diketones and a β-keto ester into the corresponding dithioacetals. Sterically hindered carbonyl compounds such as camphor and benzophenone were also converted to their corresponding thioacetals in refluxing petroleum ether in 89-94percent yields. Surprisingly, anthrone was reduced to anthracene in 91percent yield.
- Firouzabadi,Iranpoor,Amani
-
-
- Indium(III) chloride catalyzed efficient conversion of carbonyl compounds to 1,3-dithioacetals
-
Several aldehydes and ketones were efficiently converted into their corresponding dithioacetals and 1,3-dithianes in high yields using catalytic amount of indium(III) chloride in dichloromethane.
- Yadav,Subba Reddy,Pandey, Sushil Kumar
-
p. 715 - 719
(2007/10/03)
-
- Molybdenum pentachloride (MoCl5) catalyzes efficient dithioacetalization of carbonyl compounds and transdithioacetalization of O, O-acetals. This catalyst also conducts efficient non-hydrolytic deprotection of dithioacetals in the presence of dry DMSO. Part 2
-
Dithioacetalization of carbonyl compounds was performed efficiently in CH2Cl2 at room temperature in the presence of MoCl5. Highly selective transdithioacetalization of acetals was also catalyzed efficiently by this catalyst. MoCl5 performed non-hydrolytic deprotection of dithioacetals in the presence of dry DMSO.
- Firouzabadi,Karimi
-
p. 207 - 216
(2007/10/03)
-
- An efficient procedure for the preparation of cyclic ketals and thioketals catalyzed by zirconium sulfophenyl phosphonate
-
A convenient method for the preparation of cyclic ketals and thioketals using zirconium sulfophenyl phosphonate as catalyst is described.
- Curini,Epifano,Marcotullio,Rosati
-
p. 1182 - 1184
(2007/10/03)
-
- A new molecular iodine-catalyzed thioketalization of carbonyl compounds: Selectivity and scope
-
A new molecular iodine-catalyzed thioketalization of carbonyl compounds has been developed.
- Samajdar, Susanta,Basu, Manas K.,Becker, Frederick F.,Banik, Bimal K.
-
p. 4425 - 4427
(2007/10/03)
-
- Highly efficient dithioacetalization of carbonyl compounds catalyzed with iodine supported on neutral alumina
-
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.
-
p. 794 - 795
(2007/10/03)
-
- Indium tribromide-catalyzed chemoselective dithioacetalization of aldehydes in non-aqueous and aqueous media
-
Indium tribromide efficiently catalyzes the chemoselective dithioacetalization of aldehydes in the presence of ketones in dichloromethane. The catalyst is also active in water, which can be reused, in the same pot, for several times without any decrease in the yield of reaction. (C) 2000 Published by Elsevier Science Ltd.
- Ceschi,De Araujo Felix,Peppe
-
p. 9695 - 9699
(2007/10/03)
-
- Solvent free thioacetalization of carbonyl compounds catalyzed by Cu(OTf)2-SiO2
-
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.
-
p. 415 - 416
(2007/10/03)
-
- Selective Transdithioacetalization of Acetals, Ketals, Oxathioacetals and Oxathioketals Catalyzed by Envirocat EPZ10 R
-
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
-
p. 452 - 453
(2007/10/03)
-
- Tungsten hexachloride (WCl6) as an efficient catalyst for chemoselective dithioacetalization of carbonyl compounds and transthioacetalization of acetals
-
A variety of aldehydes, ketones and O,O-acetals were efficiently converted to the corresponding 1,3-dithianes and 1,3-dithiolanes by using catalytic amounts of tungsten hexachloride (WCl6) in CH2Cl2 under mild conditions.
- Firouzabadi, Habib,Iranpoor, Nasser,Karimi, Babak
-
p. 739 - 740
(2007/10/03)
-
- Selective Catalytic Transesterification, Transthiolesterification, and Protection of Carbonyl Compounds over Natural Kaolinitic Clay
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Transesterification and transthiolesterification of β-keto esters with variety of alcohols and thiols and selective protection of carbonyl functions with various protecting groups catalyzed by natural kaolinitic clay are described. The clay has been found to be an efficient catalyst in transesterifying long chain alcohols, unsaturated alcohols, and phenols to give their corresponding β-keto esters in high yields. For the first time, transthiolesterification of β-keto esters with a variety of thiols has been achieved under catalytic conditions. Clay also catalyzes selective transesterification of β-keto esters by primary alcohols in the presence of secondary and tertiary alcohols giving corresponding β-keto esters. A systematic study involving the reactivity of different nucleophiles (alcohols, amines, and thiols) toward β-keto esters is also described. Sterically hindered carbonyl groups as well as α,β-unsaturated carbonyl groups underwent protection without the deconjugation of the double bond. Chemoselective protection of aldehydes in the presence of ketones has also been achieved over natural kaolinitic clay.
- Ponde, Datta E.,Deshpande, Vishnu H.,Bulbule, Vivek J.,Sudalai, Ammugam,Gajare, Anil S.
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p. 1058 - 1063
(2007/10/03)
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- Microwave assisted preparation of 1,3-dithiolanes under solvent free conditions
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Various carbonyl compounds react efficiently with 1,2-ethylenedithiol by microwave irradiation using mildly acidic K-10 clay within a few minutes and furnish the products in high yield under solvent free conditions.
- Kad,Singh, Vasundhara,Kaur, Kanwal Preet,Singh, Jasvinder
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p. 172 - 173
(2007/10/03)
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