- An efficient synthesis of diacetates from aldehydes using beta zeolite
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A variety of aldehydes react with acetic anhydride in the presence of catalytic amount of β zeolite to afford the corresponding 1,1 diacetates in good to excellent yields.
- Kumar, Pradeep,Hegde, Vishnumurthy R.,Kumar, T. Pavan
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Read Online
- Silica-bonded S-sulfonic acid as a recyclable catalyst for chemoselective synthesis of 1,1-diacetates
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A simple and efficient procedure for the preparation of silica-bonded S-sulfonic acid (SBSSA) by reaction of 3-mercaptopropylsilica (MPS) and chlorosulfonic acid in chloroform is described. This solid acid is employed as a recyclable catalyst for the synthesis of 1,1-diacetates from aromatic aldehydes and acetic anhydride under mild and solvent-free conditions at room temperature.
- Niknam, Khodabakhsh,Saberi, Dariush,Sefat, Maryam Nouri
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Read Online
- Synthesis of sulfonated carbon-based solid acid as a novel and efficient nanocatalyst for the preparation of highly functionalized piperidines and acylals: a DFT study
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Abstract: A novel carbon-based solid-acid nanocatalyst (Sta-SO3H) was simply prepared for the first time by the thermal treatment of sulfuric acid with starch at 180?°C in a sealed autoclave. The catalytic activities of Sta-SO3H as an efficient and reusable catalyst were investigated by the condensation reaction of aldehyde, amine and β-keto ester for the synthesis of functionalized piperidines under solvent-free conditions at room temperature in good to high yields. Density functional theory calculations were used to study the structure of methyl 1,2,6-triphenyl-4-(phenylamino)-1,2,5,6-tetrahydropyridine-3-carboxylate (MPPC) as well as the thermochemistry of the multicomponent reaction. The theoretically calculated infrared and 1H nuclear magnetic resonance spectra of MPPC were compared to the experimental data. It was found that the synthesis of MPPC is exothermic accompanied by a decrease in entropy, internal energy and Gibbs free energy of reaction. Good consistency between the calculated and observed spectral data was found. Also, Sta-SO3H has been developed for the synthesis of acylals (1,1-diacetate) in high yields through the reaction of aldehydes with acetic anhydride at room temperature under solvent-free conditions. The mild conditions, eco-friendliness, excellent yields, short reaction times and use of an inexpensive and reusable catalyst are important features of this method. Graphical Abstract: [Figure not available: see fulltext.]
- Hoseinabadi, Zahra,Pourmousavi, Seied Ali,Zamani, Mahdi
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Read Online
- Phospho sulfonic acid as an efficient and recyclable solid acid catalyst for the solvent-free preparation of acylals
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Phospho sulfonic acid (PSA) acts as a highly effective and reusable catalyst for the chemo-selective protection of aldehydes with acetic anhydride under solvent-free conditions. The desirable features of this new catalytic methodology include its sustaina
- Kalla, Reddi Mohan Naidu,Park, Huiju,Hoang, Trinh Thi Kim,Kim, Il
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- Selective Synthesis of Acylated Cross-Benzoins from Acylals and Aldehydes via N-Heterocyclic Carbene Catalysis
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The utility of acylals as building blocks for selective cross-benzoin synthesis was explored in this study. The synthesis of α-acetoxyketones (O-acyl cross-benzoins) was achieved via selective N-heterocyclic carbene-catalyzed cross-benzoin reactions using acylals as aldehyde equivalents. Thus, the combination of ortho-substituted phenyl acylals and aromatic/aliphatic aldehydes as coupling substrates using bicyclic triazolium salts as precatalysts and potassium carbonate as a base in THF at reflux temperature selectively yielded O-acyl cross-benzoins.
- Onodera, Kou,Suzuki, Yumiko,Takashima, Ryo
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supporting information
p. 4197 - 4202
(2021/06/27)
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- Application of poly(Vinylbenzyltrimethylammonium tribromide) resin as an efficient polymeric catalyst in the acetalization and diacetylation of benzaldehydes
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The applications of a new supported tribromide reagent (poly(vinylbenzyltrimethylammonium tribromide) resin) were reported. This supported tribromide resin was used as a catalyst in the acetalization and diacetylation of benzaldehydes under mild conditions with high efficiency. The effects of solvents, and amount of the supported tribromide resin on the reactions were investigated. Under the optimal conditions, most of acetal and 1,1-diacetates of benzaldehydes were selectively obtained in excellent yields.
- Han, Bingbing,Hu, Junjun,Li, Xianwei,Zheng, Zubiao
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supporting information
p. 287 - 293
(2021/04/28)
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- Acylation of Phenols, Alcohols, Thiols, Amines and Aldehydes Using Sulfonic Acid Functionalized Hyper-Cross-Linked Poly(2-naphthol) as a Solid Acid Catalyst
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Abstract: The hyper-cross-linked porous poly(2-naphthol) fabricated by the Friedel–Crafts alkylation of 2-naphthol has been functionalized with sulfonic acid to obtain a solid acid catalyst. The catalyst is applied for the protection of phenol, alcohols, thiols, amines and aldehydes with acetic anhydride at room temperature. The catalytic protection using the new solid acid is featured by achieving high yield at neat condition, needing no aqueous work-up and/or chromatographic separation, and showing excellent recycling efficiency, suggesting the potential of this sulfonated porous polymers as a new protection protocol in a wide range of sustainable chemical reactions. Graphical Abstract: [Figure not available: see fulltext.].
- Kalla, Reddi Mohan Naidu,Reddy, Sirigireddy Sudharsan,Kim, Il
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p. 2696 - 2705
(2019/05/28)
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- 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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- SiO2@FeSO4 nano composite as nanocatalyst for the green synthesis 1,1-diacetates from aldehydes under solvent-free conditions
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Aldehydes compounds selective converted to 1,1-diacetates as protective reagent with SiO2@FeSO4 nano composite as effective nano catalyst at room temperature under solvent-free condition and acetic anhydride (Ac2O) as acet
- KarimKoshteh, Mostafa,Bagheri, Marziyeh,Zeynizadeh, Behzad
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p. 2780 - 2783
(2016/07/12)
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- Tungstosulfonic acid as an efficient solid acid catalyst for acylal synthesis for the protection of the aldehydic carbonyl group
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Tungstosulfonic acid (TSA) has been found to be an efficient solid acid catalyst for the protection of aldehydic carbonyl groups by geminal diacetate (acylal) formation following the nucleophilic addition of acetic anhydride under neat conditions as well as in a solvent. The TSA catalyst is fully characterized by infrared spectroscopy, wide-angle X-ray scattering analysis, and scanning electron microscopy with energy dispersive X-ray spectroscopy. The deprotection of acylals to corresponding aldehydes has also been investigated under the similar conditions. The catalyst can be reused seven times without a significant loss of activity. In addition, no chromatographic separations are needed to obtain the desired products. This method is a green approach for the chemoselective protection of aldehydes in the presence of ketones.
- Kalla, Reddi Mohan Naidu,Kim, Mi Ri,Kim, Yu Na,Kim, Il
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supporting information
p. 687 - 693
(2016/01/12)
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- Microwave-assisted green synthesis of 1,1-diacetates (acylals) using selectfluor as an environmental-friendly catalyst under solvent-free conditions
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An efficient and simple procedure has been developed for the acetylation of aldehyde by selectfluor [1-(chloromethyl)-4-fluoro-1,4-diazoniabicyclo[2,2,2]octane bis(tetrafluoroborate)] as a chemoselective and environmentally friendly catalyst under solvent-free conditions or microwave irradiation. The application of microwave irradiation improved the yields and reduced the reaction times. In this study, selective conversion of aldehydes was observed in the presence of ketones, and the deprotection of 1,1-diacetates has also been achieved using selectfluor in water as green solvent in reflux conditions. The methodology provides synergy of microwave irradiation which offers several advantages such the simple work-up procedure, short reaction time, excellent yields and environmentally benign procedure.
- Rezayati, Sobhan,Hajinasiri, Rahimeh,Erfani, Zahra
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p. 2567 - 2576
(2016/03/16)
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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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- Preparation of 1,1-diacetates from aldehydes by LiBH4 and Ac2O in the presence of cation exchange resin
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A variety of 1,1-diacetates have been produced from the corresponding aldehydes (1 mmol) by LiBH4(1.25 mmol) and Ac2O (1 mL) in the presence of DOWEX(R)50WX4 (0.5 g) as a cation exchange resinwithin 10 min at room temperature with excellent yields of the products (93-97%).
- Rezaeekhordehforosh, Reza,Khezri, Behrooz,Setamdideh, Davood
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p. 1205 - 1209
(2015/10/28)
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- Solvent-free Chemoselective Synthesis of 1,1-diacetates Catalyzed by Iron Zirconium Phosphate
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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 iron zirconium phosphate (ZPFe), 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. The catalyst 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-friendly catalyst, chemoselectivity, simple experimental and work-up procedure, solvent-free conditions and only a stoichiometric amount of AA is needed.
- Karimi, Hirbod
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p. 1000 - 1010
(2015/12/01)
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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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- Green procedures for the chemoselective synthesis of acylals and their cleavage promoted by recoverable sulfonic acid based nanoporous carbon (CMK-5-SO3H)
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A selective synthesis of gem-diacetates from the reaction of aldehydes and acetic anhydride in the presence of recyclable nanoporous solid sulfonic acid (CMK-5-SO3H) under solvent-free reaction conditions is reported. The catalyst was also found to be highly active for deprotection of resulting acylals in water. [Figure not available: see fulltext.]
- Zareyee, Daryoush,Mirzajanzadeh, Ehsan,Khalilzadeh, Mohammad Ali
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p. 1229 - 1234
(2015/10/06)
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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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- NaBH4/Ac2O/DOWEX(R)50WX4: A convenient system for fast preparation of gem-diacetates from aldehydes
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Reductive-acylalation of aldehydes has been carried out by NaBH 4/Ac2O/DOWEX(R)50WX4 system. A variety of aldehydes (1 mmol) have been reacted with Ac2O (0.5 mL) and NaBH4 (1 mmol) in the presence of DOWEX(R)50WX4 (0.5 g) for the preparation of their corresponding acylals within 1 min at room temperature with excellent yields of the products (90-95%). Ketones do not react with this system.
- Asl, Parisa Azizi,Setamdideh, Davood
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p. 940 - 944
(2014/10/16)
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- An efficient method for synthesis of acylals from aldehydes using multi-walled carbon nanotubes functionalized with phosphonic acid (MWCNTs-C-PO3H2)
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MWCNTs-C-PO3H2 has been used as an efficient, heterogeneous and reusable nanocatalyst for synthesis of acylals from aldehydes under solvent-free conditions at room temperature. A wide range of aldehydes was studied and corresponding products were obtained in good to excellent yields in short reaction times. Nanocatalyst can be easily recovered by centrifuge and reused for subsequent reactions for at least five times without deterioration in catalytic activity. The major advantages of the present method are high yields, short reaction time, recyclable catalyst and solvent-free reaction conditions at room temperature.
- Dehghani, Farzaneh,Sardarian, Ali Reza,Doroodmand, Mohammad Mehdi
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p. 1630 - 1634
(2015/01/09)
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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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- Sulfonated rice husk ash (RHA-SO3H): A highly powerful and efficient solid acid catalyst for the chemoselective preparation and deprotection of 1,1-diacetates
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Rice husk ash (RHA), as a source of amorphous silica, was treated with chlorosulfonic acid and sulfonated rice husk ash (RHA-SO3H) as a highly powerful solid acid catalyst was obtained and characterized with a variety of techniques including IR, TGA, SEM, XRD, pH analysis, Hammett acidity function and BET method. This solid acid showed excellent catalytic activity for the protection and deprotection of aldehydes with Ac2O at room temperature under solvent free conditions. The procedure gave the products in excellent yields in very short reaction times and good to high yields. Also this catalyst can be reused for several times without loss of its catalytic activity.
- Shirini, Farhad,Mamaghani, Manouchehr,Seddighi, Mohadeseh
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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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- Solvent-free catalytic preparation of 1,1-diacetates using a silica-supported functional ionic liquid as catalyst
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An efficient and convenient preparation of acylals from aldehydes and acetic anhydride, under solvent-free conditions, in the presence of a silica-supported functional ionic liquid, Si-[SbSipim][PF6], is reported. Si-[SbSipim][PF6] acts as a catalyst and can be recovered and reused four times without apparent loss of its catalytic activity.
- Kang, Li Q.,Cai, Yue Q.,Cheng, Lin
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p. 247 - 249
(2013/07/27)
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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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- Ultrasound-assisted synthesis of acylals from aldehydes using Mg(CH 3SO3)2-HOAC
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An efficient method for the synthesis of acylals from different aldehydes and acetic anhydride in the presence of magnesium methanesulfonate-acetic acid under ultrasound irradiation at room temperature is achieved. Only 1.5mol% of magnesium methanesulfonate and a small quantity of acetic acid are needed to effect the reaction. Selective conversion of aldehydes is observed in the presence of ketones. The catalyst remains active and exhibits no substantial loss of activity or selectivity in up to three reaction cycles.
- Liu, Qing,Ai, Hong-Mei,Feng, Shuai
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experimental part
p. 122 - 127
(2011/11/01)
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- Rice husk supported FeCl3 nanoparticles as an efficient and reusable catalyst for the chemoselective 1,1-diacetate protection and deprotection of aldehydes
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1,1-Diacetates were produced from a variety of aromatic aldehydes using rice husk supported FeCl3 nanoparticles as a catalyst. The procedure generally resulted in good yields (98%) of aromatic aldehydes including those carrying electron donating- or withdrawing-substituents. Deprotection of the resulting 1,1-diacetates was also achieved using the same catalyst in ethanol. This new method consistently has the advantages of excellent yields and relatively short reaction times. Further, the catalyst can be reused and recovered for several times.
- Shirini, Farhad,Akbari-Dadamahaleh, Somayeh,Mohammad-Khah, Ali
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- Schiff base complex of metal ions supported on superparamagnetic Fe 3O4@SiO2 nanoparticles: An efficient, selective and recyclable catalyst for synthesis of 1,1-diacetates from aldehydes under solvent-free conditions
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We report a new multistep method for preparing functionalized superparamagnetic Fe3O4@SiO2 possessing high saturation magnetization. During the first step, Fe3O 4@SiO2 nanosphere core-shell is synthesized using nano-Fe3O4 as the core, TEOS as the silica source and PVA as the surfactant. Then, Schiff base complex of metal is synthesized from the reaction between Schiff base and metal acetates [Co(OAc)2, Mn(OAc)2, Ni(OAc)2, Cu(OAc)2, Hg(OAc) 2, Cr(OAc)3 and Cd(OAc)2] on the Fe 3O4@SiO2 surface. The structural and magnetic properties of functionalized magnetic silica are identified by transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) instruments. Moreover, functionalized Fe3O4@SiO2 possessed a superparamagnetic characteristic with saturation magnetization value of about 34 emu/g. NMR, FT-IR, elemental analysis and XRD were also used for the identification of these structures. The catalytic ability of Fe 3O4@SiO2/Schiff base complex of metal ions was found to be an efficient nanocatalyst for the conversion of aldehydes to their corresponding 1,1-diacetates compounds under mild and solvent-free conditions at room temperature. This method gives notable advantages such as excellent chemoselectivity, mild reaction condition, short reaction times and excellent yields. Also, the aforementioned nanocatalyst can be easily recovered by a magnetic field and reused for subsequent reactions for at least 5 times without noticeable deterioration in catalytic activity.
- Esmaeilpour, Mohsen,Sardarian, Ali Reza,Javidi, Jaber
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p. 359 - 367
(2013/02/21)
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- Ultrasound-assisted synthesis of acylals catalyzed by stannum (IV) phosphomolybdate under solvent-free condition
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An efficient method for the synthesis of acylals from different aldehydes and acetic anhydride in the presence of Keggin-type stannum (IV) phosphomolybdate under ultrasound irradiation at room temperature was achieved. This method provides a new and efficient protocol in terms of cost effective of catalyst, a wide scope of substrates, and simple work-up procedure.
- Ai, Hong Mei,Liu, Qing
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experimental part
p. 299 - 301
(2012/07/17)
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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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- 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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- Chromic(III) sulfamate as a versatile catalyst for organic synthesis
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Chromic sulfamate was synthesized and used as catalyst for the first time in various organic reactions such as the transformation of aldehydes or ketones and indole to bis(indolyl)methanes, the transformation of aldehydes and acetic anhydride to 1,1-diacetates and Biginelli reaction. The advantages of the chromic sulfamate are ease of preparation, easy handling, simple work-up and versatility.
- Liu, Qing,Li, Zhen
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experimental part
p. 3208 - 3210
(2012/02/03)
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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 simple and fast method for protection of aldehydes as 1,1-diacetates using cerium(IV) sulfate as an efficient and reusable inorganic catalyst
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A simple, green, and very fast method for protection of aryl aldehydes as 1,1-diacetates promoted by cerium(IV) sulfate tetrahydrate, Ce(SO 4)2·4H2O, as a novel inorganic solid acid catalyst at room temperature and under solvent-free conditions is described. The present methodology offers several advantages, such as a simple procedure with an easy workup, very short reaction times, high yields, and the absence of any volatile and hazardous organic solvents. Copyright Taylor & Francis Group, LLC.
- Saburi, Elahe,Davoodnia, Abolghasem,Tavakoli-Hoseini, Niloofar
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experimental part
p. 1063 - 1066
(2012/02/16)
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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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- Preparation of silica-bonded propyl-diethylene-triamine-N-sulfamic acid as a recyclable catalyst for chemoselective synthesis of 1,1-diacetates
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A simple and efficient procedure for the preparation of silica-bonded propyl-diethylene-triamine-N-sulfamic acid (SPDTSA) by reaction of 3-diethylenetriamine-propylsilica (DTPS) and chlorosulfonic acid in chloroform is described. Silica-bonded propyl-diethylene-triamine-N-sulfamic acid is employed as a recyclable catalyst for the synthesis of 1,1-diacetates from aromatic aldehydes and acetic anhydride under mild and solvent-free conditions at room temperature. Catalyst could be recycled for several times without any additional treatment.
- Nouri Sefat, Maryam,Deris, Abdolah,Niknam, Khodabakhsh
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experimental part
p. 2361 - 2367
(2012/02/03)
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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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- Host (nanocavity of zeolite-Y)-guest (molybdophosphoric acid) nanocomposite materials: An efficient catalyst for solvent-free synthesis and deprotection of 1,l-diacetates
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In the present work, a mild and efficient method has been developed for the synthesis of acylals from aldehydes with acetic anhydride in the presence of molybdophosphoric acid encapsulated into dealuminated zeolite Y (MPA-DAZY) as a catalyst under solvent-free conditions at 45-55 °C in good to excellent yield. The deprotection of acylals has also been attained using this catalyst in acetonitrile. The catalyst was reused several times without efficient loss of its catalytic activity.
- Moosavifar, Maryam,Tangestaninejad, Shahram,Moghadam, Majid,Mirkhani, Valiollah,Mohammadpoor-Baltork, Iraj
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experimental part
p. 953 - 956
(2012/05/04)
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- Conversion of aldehydes to acylals using acetic anhydride in presence of catalytic amount of Fe(NO3)3.9H2O under solvent-free conditions at room temperature
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Fe(NO3)3.9H2O efficiently catalyzed the conversion of aromatic and aliphatic aldehydes to 1,1-diacetates under solvent-free conditions at room temperature. This study reports the use of Fe(NO3)3.9Hsu
- Khazaei, Ardeshir,Manesh, Abbas Amini,Rostami, Amin,Alavi-Nik, Heidar Ali,Roosta, Zahra Toodeh
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experimental part
p. 614 - 616
(2011/12/15)
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- H3PW12O40-catalysed alkylation of arenes and diveratrylmethanes: Convenient routes to triarylmethanes and to symmetrical and unsymmetrical 9,10-diaryl-2,3,6,7-tetramethoxyanthracenes
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An efficient method for the synthesis of triarylmethanes and difurylarylmethanes through solventless reactions between aldehydes and arenes in the presence of H3PW12O40 as a reusable catalyst under thermal and microwave irradiation conditions has been developed. H3PW12O40-catalysed one-pot consecutive Friedel-Crafts reactions between veratrole and aldehydes were also applied as a convenient protocol for the preparation of symmetrical 9,10-diaryl-2,3,6,7- tetramethoxyanthracenes.
- Mohammadpoor-Baltork, Iraj,Moghadam, Majid,Tangestaninejad, Shahram,Mirkhani, Valiollah,Mohammadiannejad-Abbasabadi, Kazem,Khavasi, Hamid R.
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scheme or table
p. 1357 - 1366
(2011/04/17)
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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
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experimental part
p. 6493 - 6501
(2010/11/04)
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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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- Thallium(III) chloride: A mild and efficient catalyst for acylation of alcohols, phenols and thiols, and for geminal diacylation of aldehydes under solvent-free conditions
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Thallium(III) chloride is a simple and efficient catalyst for acylation of alcohols, phenols and thiols. It is also very effective for geminal diacylation of aldehydes. The acylation reaction using acetic anhydride proceeds in excellent yield in the presence of catalytic amounts of thallium(III) chloride (1 mol%) at room temperature within relatively short reaction times (20 min). Structurally diverse alcohols, phenols, thiols and aldehydes undergo acylation under solvent-free conditions.
- Kadam, Santosh T.,Kim, Sung Soo
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experimental part
p. 3307 - 3313
(2009/05/07)
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- Synthesis of 1,1-diacetates using a new combined catalytic system: Copper p-toluenesulfonate/HOAc
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Copper p-toluenesulfonate acetic acid has been established as an efficient combined catalytic system for chemoselective conversion of aldehydes to diacetates in high yields at ambient temperature in short reaction times. For the catalytic system, the amount of copper p-toluenesulfonate reduced to 0.3 mol%. After the reaction, copper p-toluenesulfonate can be easily recovered and reused for at least 10 runs. Copyright Taylor & Francis Group, LLC.
- Wang, Min,Song, Zhiguo,Gong, Hong,Jiang, Heng
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p. 961 - 966
(2008/09/17)
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- Chemoselective synthesis of 1,1-diacetates from aldehydes in the presence of Al(HSO4)3 under mild solvent-free conditions
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A novel efficient procedure has been developed for the preparation of acylals in high yields by reaction of the corresponding aldehydes with acetic anhydride in the presence of Al(HSO4)3 as catalyst under mild (room temperature) solvent-free conditions.
- Mirjalili,Zolfigol,Bamoniri,Amrollahi,Sheikhan
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p. 852 - 854
(2008/03/11)
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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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- 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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