- Chemoselective synthesis of 1,1-diacetates under solvent-free condition using efficient heterogeneous ecofriendly catalyst: P2O5/kaolin
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An efficient and chemoselective method for the preparation of acylals from different aldehydes and acetic anhydride using.....kaolin supported catalyst (P2O5). under solvent-free conditions is described herein. The present protocol offers several advantages including use of inexpensive and non-toxic catalyst support i.e., natural kaolin. Preparation of the supported catalyst is easy, the process is simple in operation, maintaining solvent free conditions, with short reaction times, high yields and affording selective protection of aldehyde in presence of ketone.
- Rai, Nityanand,Sharma, Abha
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p. 340 - 344
(2019/05/21)
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- N-Propylsulfamic acid supported onto magnetic Fe3O4 nanoparticles (MNPs-PSA) as a green and reusable heterogeneous nanocatalyst for the chemoselective preparation and deprotection of acylals
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Abstract: N-propylsulfamic acid supported onto magnetic Fe3O4 nanoparticles (MNPs-PSA) was simply synthesized and used as a highly efficient, environmentally friendly, and chemoselective catalyst for the synthesis of 1,1-diacetates (acylals) from the one-pot condensation reaction of various aromatic aldehydes with acetic anhydride, in high yield of products (86–96%) and short reaction time (20–60?min) under solvent-free conditions at room temperature. In addition to these results, we further studied the possibility of deprotection of the resulting acylals into benzaldehyde derivatives in this catalytic system by the addition of water. More importantly, noteworthy advantages of this study are non-use of toxic organic solvents and catalysts, simple work-up procedure, short reaction time, high yield of products, and recovery and reusability of MNPs-PSA by an external magnet. Graphical Abstract: A simple and highly efficient procedure for the protection of various aldehydes with acetic anhydride in the presence of N-propylsulfamic acid supported onto magnetic Fe3O4 nanoparticles (MNPs-PSA) is reported. We further studied the possibility of deprotection of the resulting acylals into benzaldehyde derivatives in this catalytic system by the addition of water as a green solvent. The catalyst was reused several times without loss of its catalytic activity.
- Sajjadifar, Sami,Nasri, Parastoo
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p. 6677 - 6689
(2017/10/06)
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- Supported N-propylsulfamic acid onto Fe3O4 magnetic nanoparticles as a reusable and efficient nanocatalyst for the protection/deprotection of hydroxyl groups and protection of aldehydes
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N-propylsulfamic acid supported onto Fe3O4 magnetic nanoparticles (MNPs-PSA) as an efficient and magnetically reusable nanocatalyst has been reported for the tetrahydropyranylation/depyranylation of a wide variety of alcohols and phenols by changing the solvent medium. Also, the protection of aldehydes as acylals using Ac2O in the presence of catalytic amount MNPs-PSA in good to high yields at room temperature under solvent-free conditions is described. After completing the reaction, the catalyst was easily separated from the reaction mixture with the assistance of an external magnetic field and reused for several consecutive runs without significant loss of their catalytic efficiency.
- Rostami, Amin,Tahmasbi, Bahman,Abedi, Fatemeh
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p. 3689 - 3701
(2016/04/05)
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- Synthesis of 1,1-diacetates catalyzed by cellulose sulfonic acid from aldehydes and acetic anhydride
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1,1-Diacetates have been synthesized in good to excellent yields via a reaction of corresponding aldehydes and acetic anhydride in the presence of cellulose sulfonic acid as a heterogeneous catalyst at room temperature. The protection of aldehydes generated an anhydrodimer as single product under similar reaction conditions. The catalysis is equally applicable for the deprotection of acylal in acetonitrile.
- Ding, Songsong,Zhang, Jiming,Shi, Wei,Zhou, Jianhua
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p. 340 - 342
(2015/02/19)
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- Zinc zirconium phosphate as an efficient catalyst for chemoselective synthesis of 1,1-diacetates under solvent-free conditions
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In the present study, a mild, rapid, and efficient method for the protection of aldehydes with acetic anhydride (AA) in the presence of zinc zirconium phosphate (ZPZn) as a nano catalyst, at room temperature is reported. Selective conversion of aldehydes was observed in the presence of ketones. Under these conditions, different aldehydes bearing electron-withdrawing and electron-donating substituents were reacted with AA and the corresponding 1,1-diacetates (acylals) were obtained in high to excellent yields. The steric and electronic properties of the different substrates had a significant influence on the reaction conditions. Also, the deprotection of 1,1-diacetates has been achieved using this catalyst in water. This nanocatalyst was characterized by several physico-chemical techniques. It was recovered easily from the reaction mixture, regenerated and reused at least 7 times without significant loss in catalytic activity. This protocol has the advantages of easy availability, stability, reusability of the eco-friendliness, chemoselectivity, simple experimental and work-up procedure, solvent-free conditions and usage of only a stoichiometric amount of AA.
- Hajipour, Abdol R,Karimi, Hirbod
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p. 1945 - 1955
(2015/12/30)
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- Poly(4-vinylpyridinium) perchlorate as an efficient solid acid catalyst for the chemoselective preparation of 1,1-diacetates from aldehydes under solvent-free conditions
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Poly(4-vinylpyridinium) perchlorate has been used as a supported, recyclable, environmentally-benign catalyst for the formation of acylals from aliphatic and aromatic aldehydes in good to excellent yields under solvent-free conditions. Notably, the reaction conditions were tolerant of ketones. This methodology offers several distinct advantages, including its operational simplicity and high product yield, as well as being green in terms of avoiding the use of toxic catalysts and solvents. Furthermore, the catalyst can be recovered and reused several times without any loss in its activity.
- Khaligh, Nader Ghaffari
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p. 329 - 334
(2014/04/03)
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- Functionalized Poly(Amidoamine) Dendrimer as a Strong Ionic Br?nsted Acid Organocatalyst for Protection/Deprotection of Aldehydes
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Poly(amidoamine) dendrimer (PAMAM) was successfully functionalized by chlorosulfonic acid to form an strong ionic acid catalyst. The resulting polymeric catalyst was shown to be an efficient catalyst for the synthesis of 1,1-diacetyl from aldehydes under free solvent conditions at room temperature. Also, the deprotection of the resulting aldehydes was investigated under catalytic conditions. The Hammett acidity function of catalyst showed that catalyst is a strong Br?nsted acid. Due to the multi-functional nature of PAMAM, the catalyst has high loading level of acidic protons.
- Pourjavadi, Ali,Hosseini, Seyed Hassan
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p. 1794 - 1801
(2015/10/29)
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- P4VP-H2SO4-catalyzed chemoselective protection of aldehydes to acylal along with deprotection reactions
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Poly(4-vinylpyridine)-supported sulfuric acid is an excellent reusable heterogeneous catalyst for the chemoselective synthesis of 1,1- diacetates(acylal) from aldehydes in dichloromethane at room temperature within a few minutes. The protection of salicyaldehyde generated an anhydro-dimer as single product under similar reaction conditions. The catalyst is equally applicable for the deprotection of acylal in acetonitrile. The catalyst was prepared by the wet impregnation technique.
- Dutta, Papia,Sarma, Parishmita,Borah, Ruli
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p. 1378 - 1386
(2013/05/09)
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- Ultrasound assisted the chemoselective 1,1-diacetate protection and deprotection of aldehydes catalyzed by poly(4-vinylpyridinium)hydrogen sulfate salt as a eco-benign, efficient and reusable solid acid catalyst
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Poly(4-vinylpyridinium) hydrogen sulfate solid acid was found to be efficient catalyst for preparation of 1,1-diacetate using ultrasound irradiation at ambient temperature and neat condition. Deprotection of the resulting 1,1-diacetates were achieved using the same catalyst in methanol solvent under ultrasound irradiation at room temperature. This new method consistently has the advantage of excellent yields and short reaction times. Utilization of solvent free, simple reaction conditions, isolation, and purification makes this manipulation very interesting from an economic and environmental perspective. Further, the catalyst can be reused and recovered for several times.
- Khaligh, Nader Ghaffari,Shirini, Farhad
-
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- A succinimide-N-sulfonic acid catalyst for acetylation reactions in absence of a solvent
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A small amount of succinimide-N-sulfonic acid efficiently catalyzed the acetylation of a variety alcohols, phenols, thiols, amines and aldehydes with acetic anhydride at room temperature under solvent free conditions. This catalyst has the advantages of excellent yields and short reaction times and the reaction can be carried out on a large scale, which makes it potentially useful for industrial applications.
- Shirini, Farhad,Khaligh, Nader Ghaffari
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p. 695 - 703
(2013/08/25)
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- PEG-SO3H as an efficient and reusable catalyst for chemoselective synthesis of 1,1-diacetates
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An efficient and convenient procedure of the synthesis of 1,1-diacetates from aromatic aldehydes and acetic anhydride under mild and solvent-free conditions at room temperature, in the presence of PEG-SO3H is reported. PEG-SO3H acts as a catalyst and can be recovered and reused eight times without apparent loss of its catalytic activity.
- Zong, Ying-Xiao,Wang, Jun-Ke,Niu, Yu-Ying,Li, Zheng-Liang,Song, Zheng-En,Quan, Zheng-Jun,Wang, Xi-Cun,Yue, Guo-Ren,Pan, Yi
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p. 140 - 142
(2013/06/26)
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- Chemoselective synthesis of geminal diacetates (acylals) using eco-friendly reusable propylsulfonic acid based nanosilica (SBA-15-Ph-PrSO3H) under solvent-free conditions
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An expeditious method for the acetylation of aldehydes by mesoporous solid sulfonic acid (SBA-15-Ph-PrSO3H) under solvent-free reaction conditions was described. The route furnished selectively and in excellent yields the corresponding 1,1-diacetates starting from aldehydes and acetic anhydride using the environmentally friendly catalyst. The catalyst was found to be highly active and selective and could be recycled several times.
- Zareyee, Daryoush,Moosavi, Sayed M.,Alaminezhad, Alireza
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p. 227 - 231
(2013/08/23)
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- ZSM-5-SO3H as a novel, efficient, and reusable catalyst for the chemoselective synthesis and deprotection of 1,1-diacetates under eco-friendly conditions
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ZSM-5 has been modified as supported sulfuric acid (ZSM-5-SO3H) and introduced for the first time as a mild, convenient, reusable, and heterogeneous catalyst. Various types of aldehydes were efficiently converted to their 1,1-diacetates using a catalytic amount of ZSM-5- SO3H in excellent yields under solvent-free and heterogeneous conditions at room temperature. The deprotection of 1,1-diacetates has also been achieved using this novel catalyst in ethanol. The procedure is operationally simple, environmentally benign, and only a stoichiometric amount of anhydride is used. Springer-Verlag 2011.
- Massah, Ahmad Reza,Kalbasi, Roozbeh Javad,Shafiei, Anahita
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experimental part
p. 643 - 652
(2012/07/14)
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- High-valent titanium(IV)salophen: An efficient catalyst for rapid conversion of aldehydes to 1,1-diacetates with acetic anhydride
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In the present work, a mild and highly efficient method for protection of aldehydes with acetic anhydride in the presence of high-valent titanium (IV) salophen trifluoromethanesulfonate, [TiIV(salophen)(OTf) 2], at room temperature is reported. Under these conditions, different aldehydes bearing electron-withdrawing and electron-donating substituents were reacted with acetic anhydride and the corresponding 1,1-diacetates were obtained in good to excellent yields. The results showed that the yields were higher for aldehydes bearing electron-withdrawing substituents such as nitro, chloro, bromo and 3-methoxy, while aldehydes containing electron donating groups such as 4-methoxy and 4-methyl produced the lower yields. The catalyst was reused several times without loss of its catalytic activity.
- Yadegari, Maryam,Moghadam, Majid,Tangestaninejad, Shahram,Mirkhani, Valiollah,Mohammadpoor-Baltork, Iraj
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experimental part
p. 102 - 105
(2012/07/02)
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- A rapid, convenient and chemoselective synthesis of acylals from aldehydes catalyzed by reusable nano-ordered MCM-41-SO3H
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Acylals were prepared by direct condensation of aldehydes with acetic anhydride using nano-ordered MCM-41-SO3H as a heterogeneous catalyst under solvent-free conditions at room temperature in a very short reaction time and excellent yields. The catalyst is recyclable, non-toxic, neither air nor moisture sensitive, and easy to handle. High chemoselectivity toward aldehydes in the presence of ketones is another advantage of the present method which provides selective protection of aldehydes in their mixtures with ketones.
- Tourani, Hesam,Naimi-Jamal, Mohammad Reza,Dekamin, Mohammad Ghorban,Amirnejad, Meysam
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p. 1072 - 1076
(2013/02/22)
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- Introduction of N-sulfonic acid poly(4-vinylpyridinum) chloride as an efficient and reusable catalyst for the chemoselective 1,1-diacetate protection and deprotection of aldehydes
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N-sulfonic acid poly(4-vinylpyridinium) chloride is easily prepared by the reaction of poly(4-vinylpyridine) with neat chlorosulfonic acid. This reagent can be used as an efficient catalyst for the preparation of 1,1-diacetates at room temperature and neat condition. Deprotection of the resulting 1,1-diacetates can also be achieved using the same catalyst in methanol. This new method consistently has the advantages of excellent yields and short reaction times. Further, the catalyst can be reused and recovered for several times.
- Shirini, Farhad,Jolodar, Omid Goli
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experimental part
p. 61 - 69
(2012/04/17)
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- Synthesis and characterization of BEA-SO3H as an efficient and chemoselective acid catalyst
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BEA zeolite was synthesized under hydrothermal condition and modified with various amounts of chlorosulphonic acid. It was characterized by XRD, XRF, FT-IR, BET, thermogravimetric analysis and SEM techniques. Catalytic activity of BEA-SO3H was tested for the synthesis of 1,1-diacetates from a variety of aromatic and aliphatic aldehydes including those carrying electron donating or withdrawing substituents by acetic anhydride. At optimized conditions, The BEA-SO3H (28 wt.%) catalyst showed good yield at very short time for the synthesis and deprotection of 1,1-diacetates. Furthermore, BEA-SO3H was found to be recyclable for the protection of aldehydes with acetic anhydride under solvent-free and room temperature conditions. This method is a green approach for the protection of aldehydes in the presence of ketones.
- Kalbasi, Roozbeh Javad,Massah, Ahmad Reza,Shafiei, Anahita
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experimental part
p. 51 - 59
(2011/04/15)
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- Amorphous carbon-silica composites bearing sulfonic acid as solid acid catalysts for the chemoselective protection of aldehydes as 1,1-diacetates and for N-, O- and S-acylations
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Amorphous carbon-silica composites bearing sulfonic acid derived from inexpensive natural organic compounds (glucose, maltose, cellulose, chitosan and starch) were prepared by partial carbonization followed by sulfonation and their catalytic activity was evaluated for the protection of aldehydes as 1,1-diacetates and for N-, O- and S-acylations under solvent-free conditions. Different biomaterials have been chosen, with a view to select the most active solid acid catalyst. Carbon-silica composites were characterized by FTIR, XRD and elemental analysis. Sulfonated carbon-silica composite derived from starch was found to be the most active and could be recycled for several runs without loss of significant activity. It was also characterized by TGA, SEM and TEM.
- Gupta, Princy,Paul, Satya
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experimental part
p. 2365 - 2372
(2011/10/31)
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- A convenient and efficient protocol for the synthesis of acylals catalyzed by Br?nsted acidic ionic liquids under ultrasonic irradiation
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The synthesis of acylals (1,1-diacetates) via the reactions of aldehydes with acetic anhydride was carried out in 85-97% yields at room temperature under ultrasound irradiation catalyzed by the Br?nsted acidic ionic liquid [bmpy]HSO4. This method provides several advantages, such as solvent-free conditions, operational simplicity, higher yields, and reduced environmental consequences. The ionic liquid was recovered and reused.
- Borikar, Sanjay P.,Daniel, Thomas
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experimental part
p. 928 - 931
(2012/03/08)
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- [HSO3-pmim][CH3SO3] as an efficient catalyst for chemoselective synthesis of 1,1-diacetates under ultrasound irradiation
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A mild and efficient method for the chemoselective preparation of 1,1-diacetates catalyzed by 1-methyl-3-(3- sulfopropyl)-imidazolium methyl sulfate under ultrasound irradiation has been developed. The yields are ranged in 90%-98%. This protocol offered several advantages including low catalyst loading, high yields, short reaction time and environmentally benign approach.
- Li, Chao,Guo, Tao,Zhou, Xin,Wang, Chun,Ma, Jing-Jun,Li, Jin-Bin
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experimental part
p. 484 - 487
(2012/04/11)
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- A new and efficient procedure for the production of 1,1-diacetate from corresponding aldehydes promoted by silica chromate (SiO2-O-CrO 2-O-SiO2)
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Chemical Equation Presented A wide range of aromatic aldehydes has been selectively converted to 1,1-diacetates using silica chromate (SiO 2-O-CrO2-O-SiO2) under solvent-free conditions at room temperature in moderate to good yields. This protocol is mild and efficient compared to other reported methods. Copyright Taylor & Francis Group, LLC.
- Bamoniri, Abdolhamid,Ghorbani-Choghamarani, Arash,Mirjalili, Bi Bi Fatemeh
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experimental part
p. 381 - 388
(2011/04/22)
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- SnCl2.2H2O and Ni(OAc)2.4H2O: Efficient heterogeneous inorganic catalysts for the chemoselective synthesis of geminal diacetates (acylal) under solvent-free conditions
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SnCl2.2H2O and Ni(OAc)2.4H2O were found to be efficient catalysts for preparation of 1,1-diacetates under solvent-free conditions at room temperature. Easy work-up and low cost are important features from the environmental and economical points of view, are distinct aspects of this research. Very good to exellent yields, short reaction times, non-toxicity and stability of the catalysts are noteworthy advantages of this method.
- Khazaei, Ardeshir,Manesh, Abbas Amini,Alavi-Nik, Heidar Ali,Roosta, Zahra Toodeh
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experimental part
p. 627 - 630
(2011/12/15)
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- An efficient and chemoselective procedure for acylal synthesis
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A novel heterogeneous efficient procedure has been developed for the chemoselective synthesis of acylals (1,1-diacetates) under solvent-free conditions. A novel catalyst prepared by the sulfuric acid catalyzed copolymerization of p-toluenesulfonic acid and paraformaldehyde displays extremely high activities for the title reactions, affording average yields over 90% within several minutes. A comparative study showed that the novel catalyst has much higher activity than other catalysts used for this purpose. Besides, the novel catalyst displays chemoselectivity for the protection of aldehydes in the presence of ketones. In addition the high acidity (4.0 mmol/g), thermal stability (200 °C) and easy reusability make the novel catalyst one of the best choices for the process.
- Fan, Da-He,Wang, Hui,Mao, Xing-Xing,Shen, Yong-Miao
-
experimental part
p. 6493 - 6501
(2010/11/04)
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- Chemoselective synthesis of 1,1-diacetates from aldehydes using anhydrous cobalt(II) bromide under solvent-free conditions
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A mild and efficient method has been developed for the chemoselective preparation of 1,1-diacetates (acylals) from aldehydes catalyzed in the presence of a catalytic amount (0.1mmol) of anhydrous cobalt(II) bromide under solvent-free conditions. The remarkable selectivity under mild and neutral conditions, excellent yields, short reaction time, and easily available and inexpensive catalyst are important features of this method.
- Meshram, Gangadhar A.,Patil, Vishvanath D.
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experimental part
p. 442 - 449
(2010/04/02)
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- Silica phosphoric acid: An efficient and recyclable catalyst for the solvent-free synthesis of acylals and their deprotection in MeOH
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Silica phosphoric acid was used as an efficient, mild, and recyclable solid catalyst for the synthesis of acylals from various structurally diverse aldehydes and acetic anhydride under solvent-free conditions. The acylation of aldehydes was highly chemoselective, and no ketone was acylated, which provided a method for the synthesis of acylals from aldehydes in the presence of ketones. Silica phosphoric acid-catalyzed deprotection of acylals to the corresponding aldehydes in MeOH has also been developed with excellent yield. The deprotection of the acylals of aromatic aldehydes took priority over those of aliphatic aldehydes. Copyright Taylor & Francis Group, LLC.
- Zhang, Fuyi,Liu, Hong,Zhang, Qing-Ju,Zhao, Yu-Fen,Yang, Feng-Ling
-
experimental part
p. 3240 - 3250
(2010/12/24)
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- NbCl5 as an efficient catalyst for chemoselective synthesis of 1,1-diacetates under solvent-free conditions
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A mild and efficient method for the chemoselective preparation of 1,1-diacetates catalyzed by NbCl5(5mmol%) under solvent-free conditions has been developed. The yields are in the range of 93-98%. This protocol offered several advantages, including low catalyst loading, good yields, short reaction times, and environmentally friendliness.
- Gao, Shu-Tao,Zhao, Ying,Li, Chao,Ma, Jing-Jun,Wang, Chun
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experimental part
p. 2221 - 2229
(2009/10/17)
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- Solvent free diacetylation of aldehydes using a solid acid under microwave irradiation and a simple route to their regeneration
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A simple solvent-free microwave mediated procedure for the selective protection of aldehydes by conversion to their 1,1-diacetates is reported. The resultant diacetates were deprotected to generate the aldehyde using aqueous formic acid in the presence of a surfactant in high yield.
- Barua, Akashi,Das, Pranab J.
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p. 938 - 941
(2008/12/23)
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- P2O5/Al2O3 as an efficient heterogeneous catalyst for chemoselective synthesis of 1,1-diacetates under solvent-free conditions
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An efficient and chemoselective method for the preparation of acylals from different aldehydes using P2O5/Al2O3 and acetic anhydride under solvent-free conditions.
- Hajipour, Abdol R.,Zarei, Amin,Ruoho, Arnold E.
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p. 2881 - 2884
(2007/10/03)
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- Preparation of geminal diacylates (acylals) of aldehydes - Scope and reactivity of aldehydes with acid anhydrides
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The geminal diacylates of a variety of aldehydes were prepared in good yields without any catalysts or solvent by simply refluxing the aldehydes with aliphatic acid anhydrides. The scope of the reactions and relative reactivities of aldehydes and acid anhydrides were examined. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
- Rahman, Motiur A. F. M.,Jahng, Yurngdong
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p. 379 - 383
(2007/10/03)
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- Physicochemical behaviour of copper(II) complexes of chelated diamine ligands: Catalytic role of diaquabis(ethylenediamine)copper(II) perchlorate in acylal formation
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Preparation and properties of a few chelated diamine complexes of copper(II) are reported. The compounds, [Cu(en)2(H2O) 2](ClO4)2 (1), [Cu(tmen)2(H 2O)2](C1O4)2 (2), [Cu 2(en)2Cl4]n (3) and [Cu 2(en)2(SO4)2(H2O) 4].2H2O (4) have been prepared in moderate to excellent yields and characterized by various physicochemical techniques. The structure of [Cu2(en)2Cl4]n (3) has been determined by single crystal X-ray diffraction. Complex 3 crystallizes in monoclinic space group P21/m, with unit cell parameters a = 6.7850 (14) A, b = 5.7600(12)A, c = 8.2240(16)A, β= 93.75(3)°, V = 320.7(1)A3. The structure has been solved by direct method and refined by full-matrix least squares to final R1 = 0.0460, wR2 = 0.1249 and GooF = 1.135 for all 818 reflections. Each copper atom in complex 3 is present in a distorted octahedral environment created by a chelating ethylenediamine ligand and four chlorine atoms. Two adjacent parallel -Cu-Cl-Cu- chains joined by short Cu-Cl bonds give rise to a zigzag ribbon-like polymer. Complex 1 has been studied as a catalyst for the conversion of aromatic aldehydes to acylals under solvent-free conditions at room temperature.
- Sarmah, Purabi,Singha, Sunita,Chakrabarty, Rajesh,Bora, Sanchay J.,Das, Birinchi K.
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p. 1929 - 1937
(2008/03/15)
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- Solvent-free chemoselective synthesis of 1,1-diacetates catalyzed by Cu(NO3)2·3H2O
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1,1-Diacetates have been synthesized by the reaction of a variety of aldehydes with acetic anhydride in the presence of cupric nitrate as catalyst under solvent-free conditions. Ketones were not converted to the corresponding diacetates under these conditions. Copyright Taylor & Francis Group, LLC.
- Heravi, Majid M.,Bakhtiari, Khadijeh,Tehrani, Maryam H.,Oskooie, Hossein A.
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p. 1121 - 1126
(2008/02/01)
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- Cupric sulfate pentahydrate: A mild and efficient catalyst for the chemoselective synthesis of 1,1-diacetates from aldehydes in a solvent-free system
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Cupric sulfate pentahydrate was found to be an efficient catalyst for the protection of aldehydes as 1,1-diacetates in high yields in a solvent-free system at room temperature. Ketones are not affected under these reaction conditions. Springer-Verlag 2006.
- Heravi, Majid M.,Taheri, Shima,Bakhtiari, Khadijeh,Oskooie, Hossein A.
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p. 1075 - 1078
(2007/10/03)
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- Ytterbium perfluorooctanesulfonate catalyzed synthesis of acylals from aldehydes and acetic anhydride in a fluorous biphasic system
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Ytterbium perfluorooctanesulfonate [Yb(OPf)3] catalyses the highly efficient synthesis of acylals from aldehydes and acetic anhydride in a fluorous biphase system (FBS) composed of toluene and perfluorodecalin. The fluorous phase containing the fluorous catalyst is easily separated and can be reused several times without significant loss of catalytic activity.
- Yi, Wen-Bin,Yin, Ya-Qing,Cai, Chun
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p. 1563 - 1566
(2007/10/03)
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- Heteropolyacid encapsulated into mesoporous silica framework for an efficient preparation of 1,1-diacetates from aldehydes under a solvent-free condition
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Acylals were prepared from aliphatic and aromatic aldehydes using heteropolyacid (SiPW-8) encapsulated into the framework of mesoporous silica as catalysts in a solvent-free procedure. The catalyst was very effective and reusable for the production of 1,1-diacetates from aldehydes under a mild reaction condition.
- Wang, Jianmin,Yan, Liang,Qian, Guang,Yang, Keli,Liu, Haitao,Wang, Xiaolai
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p. 8309 - 8312
(2007/10/03)
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- An efficient and practical procedure for preparation of gem-diacetates from aldehydes catalysed by magnesium perchlorate
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A mild and efficient method for the preparation of grem-diacetates from aldehydes with acetic anhydride is described using a catalytic amount of magnesium perchlorate giving excellent yields under solvent-free conditions.
- Yang, Shu-Tao
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p. 199 - 202
(2007/10/03)
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- An efficient procedure for the synthesis of 1,1-diacetates from aldehydes with acetic anhydride catalyzed by silica sulfate
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The reaction of aldehyde with acetic anhydride catalyzed by silica sulfate results in 1,1-diacetates in high yields at room temperature.
- Jin, Tong-Shou,Zhao, Ying,Gu, Shu-Qing,Liu, Li-Bin,Li, Tong-Shuang
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p. 1054 - 1056
(2007/10/03)
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- Simple synthesis of geminal diacetates (Acylals) of aromatic aldehydes
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The geminal diacetates of aromatic aldehydes were prepared from corresponding aldehydes by refluxing with acetic anhydride without any catalysts or even any additional solvent. Copyright Taylor & Francis Group, LLC.
- Rahman, Motiur A. F. M.,Jahng, Yurngdong
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p. 1213 - 1220
(2007/10/03)
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- Dodecatungstophosphoric acid (H3PW12O40): A novel and efficient recyclable catalyst for synthesis of 1,1-diacetates from aromatic aldehydes in solvent-free system and their deprotection
-
A facile and efficient method for the formation of 1,1-diacetates from a variety of aldehydes in the presence of a catalytic amount of H 3PW12O40 and acetic anhydride was achieved in good yields at room temperature. The deprotection of the resulting acylals is achieved using the same catalyst in acetone. Copyright Taylor & Francis Group, LLC.
- Heravi, Majid M.,Derikvand, Fatemeh,Bamoharram, Fatemeh F.
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p. 3109 - 3115
(2007/10/03)
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- Solid silica sulfuric acid (SSA) as a novel and efficient catalyst for acetylation of aldehydes and sugars
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Acetylation of aldehydes and sugars catalyzed by solid silica sulfuric acid (SSA) is described. In these reactions SSA shows a highly catalytic nature: easy to handle procedure, short reaction time, recycle exploitation, insensitivity to air and moisture, excellent isolated yields. The catalyst could be recycled at least five times.
- Wu, Hui,Shen, Yang,Fan, Li-yan,Wan, Yu,Shi, Da-qing
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p. 7995 - 7998
(2007/10/03)
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- A simple and efficient method for the synthesis of gem-diacetates from aldehydes and ketones catalysed by gallium triiodide
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Aldehydes or ketones reacted with acetic anhydride in dichloromethane at ambient temperature to produce gem-diacetates in good to excellent yields in the presence of gallium triiodide, which was generated in situ from gallium and iodine. This catalyst was also useful for the deprotection of carbonyl compounds in the presence of water.
- Sun, Peipei,Hu, Zhixin
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p. 659 - 660
(2007/10/03)
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- Lithium chloride-assisted chemoselective conversion of aldehydes into geminal diacetates under solvent-free conditions
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A mixture of lithium chloride and acetic anhydride was used for converting aldehydes into geminal diacetates under solvent-free conditions in high yields. Copyright Taylor & Francis, Inc.
- Bosco, J.W. John,Purkayastha,Raju, B. Rama,Saikia, Anil K.
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p. 1301 - 1305
(2007/10/03)
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- Silica sulfuric acid as an efficient heterogeneous catalyst for the synthesis of 1,1-diacetates under solvent-free conditions
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An efficient method for the preparation of acylals from different aldehydes in the presence of silica sulfuric acid and acetic anhydride under solvent-free conditions is reported. Georg Thieme Verlag Stuttgart.
- Hajipour, Abdol R.,Zarei, Amin,Khazdooz, Leila,Mirjalili, Bi Bi F.,Sheikhan, Nafise,Zahmatkesh, Saeed,Ruoho, Arnold E.
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p. 3644 - 3648
(2007/10/03)
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- Acetonyltriphenylphosphonium bromide (ATPB): A versatile reagent for the acylation of alcohols, phenols, thiols and amines and for 1,1-diacylation of aldehydes under solvent-free conditions
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A wide variety of alcohols, phenols, amines and thiols may easily be converted into the corresponding acetate derivatives by treatment with acetic anhydride (1.5-2.0 equivalents) in the presence of acetonyltriphenylphosphonium bromide (ATPB; 5 mol %) in good yields at room temperature. With the same precatalyst, both aliphatic and aromatic aldehydes can also be transformed into the corresponding gemdiacetates under reflux conditions.
- Khan, Abu T.,Choudhury, Lokman H.,Ghosh, Subrata
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p. 2782 - 2787
(2007/10/03)
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- An efficient and practical procedure for synthesis of 1,1-diacetates from aldehydes catalyzed by zirconium sulfate tetrahydrate-silica gel
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A facile and efficient procedure for synthesis of 1,1-diacetates from aldehydes with acetic anhydride was described using zirconium sulfate tetrahydrate-silica gel as catalyst in excellent yields under mild reaction conditions.
- Jin, Tongshou,Feng, Guoliang,Yang, Mina,Li, Tongshuang
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p. 1645 - 1651
(2007/10/03)
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- Indium tribromide as a highly efficient and versatile catalyst for chemoselective synthesis of acylals from aldehydes under solvent-free conditions
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A mild and efficient method has been developed for the chemoselective preparation of acylals from aldehydes in the presence of catalytic amounts (0.01-1.0 mol%) of InBr3 under solvent-free conditions in very good to excellent yields.
- Yin, Liang,Zhang, Zhan-Hui,Wang, Yong-Mei,Pang, Mei-Li
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p. 1727 - 1730
(2007/10/03)
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- Facile synthesis of 1,1-diacetates from aldehydes using environmentally benign solid acid catalyst under solvent-free conditions
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Variety of aromatic and aliphatic aldehydes are converted into their 1,1-diacetates in the presence of environmentally benign Mo/TiO 2-ZrO2 solid acid catalyst in good to excellent yields under solvent-free conditions.
- Reddy, Benjaram M.,Sreekanth, Pavani M.,Khan, Ataullah
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p. 1839 - 1845
(2007/10/03)
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- Solvent-free catalytic preparation of 1,1-diacetates from aldehydes using a Wells-Dawson acid (H6P2W18O62·24H 2O)
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Aromatic and aliphatic aldehydes are transformed in 1,1-diacetates (acylals) in mild conditions, by a treatment with acetic anhydride and a Wells-Dawson acid (H6P2W18O62·24H 2O). gem-Diacetylation proceeds in Ac2O with a little as 1% mol Wells-Dawson acid at room temperature and under solventless conditions, obtaining very good to excellent yields (88-98%) of 1,1-diacetates (19 examples). Neither 4-dimethylaminobenzaldehyde nor ketones react under the same conditions.
- Romanelli, Gustavo P.,Thomas, Horacio J.,Baronetti, Graciela T.,Autino, Juan C.
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p. 1301 - 1303
(2007/10/03)
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- Lithium trifluoromethanesulfonate (LiOTf) as a recyclable catalyst for highly efficient acetylation of alcohols and diacetylation of aldehydes under mild and neutral reaction conditions
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A variety of alcohols and aldehydes were reacted with acetic anhydride at room temperature in the presence of a catalytic amount of lithium triflate (LiOTf) to produce the corresponding esters and 1,1-diacetates, respectively, in good to excellent yields under essentially neutral reaction conditions. Sensitive functional groups such as PhCO2-, OMe, and OTBDMS ethers survived intact under the described reaction conditions.
- Karimi, Babak,Maleki, Jafar
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p. 4951 - 4954
(2007/10/03)
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- A novel and efficient conversion of aldehydes to 1,1-diacetates catalyzed with FeCl3/SiO2 under microwave irradiation
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1,1-Diacetates (3) are effectively synthesized in few minutes by acylation reaction of aldehydes with acetic anhydride in the presence of FeCl3/SiO2 under microwave irradiation.
- Wang, Cunde,Li, Minghua
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p. 3469 - 3473
(2007/10/03)
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