- METHOD FOR PRODUCING DICARBOXYLIC ACID
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A method for producing dicarboxylic acid. The method includes: subjecting a raw material system including a cyclic olefin and a lower monocarboxylic acid to an addition reaction in the presence of an addition reaction catalyst to generate an intermediate product system including cyclic carboxylic acid ester; and subjecting the intermediate product system including cyclic carboxylic acid ester to a ring-opening and oxidation reaction in the presence of an oxidant and an oxidation catalyst to generate a corresponding dicarboxylic acid product. The addition reaction in the dicarboxylic acid synthesis route achieves a high single-pass conversion rate, and the selectivity of the corresponding cyclic carboxylic acid ester is high. The addition-oxidation synthesis route achieves faster reaction rates for both the addition reaction and oxidation reaction, and high yield of corresponding dicarboxylic acid product. The addition-oxidation based synthesis route is suitable for continuous, stable and large-scale production of corresponding dicarboxylic acid product.
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Paragraph 0110
(2021/05/21)
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- Consecutive addition esterification and hydrolysis of cyclic olefins catalyzed by multi-SO3H functionalized multi heteropolyanion-based ionic hybrids undersolvent-free conditions
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An efficient protocol for the synthesis of cycloalkyl carboxylates and alcohols from cyclic olefins is described. The cyclic olefins were converted to corresponding target molecules under solvent-free conditions catalyzed by two novel multi-SO3H functionalized multi heteropolyanion-based ionic hybrids through one-pot consecutive addition esterification and hydrolysis reactions. This approach has several advantages, including high yield, simple workup and simple purification.
- Zheng, Guocai,Li, Xinzhong
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p. 933 - 941
(2019/03/17)
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- Application of Yttrium Iron Garnet as a Powerful and Recyclable Nanocatalyst for One-Pot Synthesis of Pyrano[2,3-c]pyrazole Derivatives under Solvent-Free Conditions
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The application of yttrium iron garnet (YIG) superparamagnetic nanoparticles as a new recyclable and highly efficient heterogeneous magnetic catalyst for one-pot synthesis of pyrano[2,3-c]pyrazole derivatives under solvent-free conditions, as well as etherification and esterification reactions are described. The advantages of the proposed method include the lack of organic solvents, clean reaction, rapid removal of the catalyst, short reaction times, excellent yields, and recyclability of the catalyst.
- Sedighinia,Badri,Kiasat
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p. 1755 - 1763
(2020/01/11)
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- 4-Imidazol-1-yl-butane-1-sulfonic acid ionic liquid: Synthesis, structural analysis, physical properties and catalytic application as dual solvent-catalyst
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4-Imidazol-1-yl-butane-1-sulfonic acid (ImBu-SO3H) has been successfully synthetized and fully characterized by FT-IR and high-resolution NMR spectroscopy (1H, 13C). The “plausible” alternative structures of ImBu-SO3H were discussed on the basis of its NMR data. The ionic liquid showed interesting dual solvent-catalyst property, which was studied experimentally for the acetylation of a variety of functionalized alcohols, phenols, thiols, amines and α-tocopherol (α-CTP) as the most active form of vitamin E with acetic anhydride and which provided good yields within a short reaction time. ImBu-SO3H was successfully recycled by product extraction with an average recovered yield of 82% for 5 subsequent runs. The catalytic activity of the recycled ImBu-SO3H showed almost no loss even after five consecutive runs.
- Khaligh, Nader Ghaffari,Mihankhah, Taraneh,Johan, Mohd Rafie,Juan, Joon Ching
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p. 866 - 878
(2019/07/12)
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- Method for preparing cyclopentanol from cyclopentene
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The invention relates to a method for preparing cyclopentanol from cyclopentene. Cyclopentene and acetic acid are mixed for an esterification reaction, cyclopentyl acetate is generated, a catalyst adopts cerium nitrate modified sulfonyl cation exchange resin during a transesterification reaction, and the exchange capacity of cerium ions is 10%-30% of that of resin mass; the conversion rate of the esterification reaction is remarkably increased; during the transesterification reaction of crude cyclopentyl acetate and methanol, the transesterification reaction is catalyzed through granular CaO and a sodium methylate composite catalyst dissolved in a reaction liquid, cyclopentyl acetate and methanol can be catalyzed for the transesterification reaction, a small amount of water brought into reaction raw materials can be removed, difficulty caused by CaO hydrolysis and product separation is avoided, and the pollution problem of an existing process is effectively solved.
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Paragraph 0035; 0039; 0040
(2017/02/23)
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- Preparation, characterization and application of RHA/TiO2 nanocomposites in the acetylation of alcohols, phenols and amines
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In this work, anatase-phase nano-titania was prepared by embedding in rice husk ash, and identified using a variety of techniques. The obtained nanocomposite (RHA/TiO2) was used as a green and inexpensive catalyst for the promotion of the acetylation of alcohols, phenols and amines with Ac2O at room temperature under solvent free conditions. The procedure gave the products in excellent yields during all reaction times. Also this catalyst can be reused for several times without loss of its catalytic activity.
- Seddighi, Mohadeseh,Shirini, Farhad,Goli-Jolodar, Omid
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p. 1003 - 1010
(2016/08/08)
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- A process for the preparation of acetate
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The invention relates to an acetate preparation method. The method comprises the following steps: carrying out a contact reaction of sec-butyl acetate and alcohol in the presence of an ester exchange catalyst under an ester exchange reaction condition, adding products obtained after the contact reaction into a separation tower, controlling the tower top temperature to separate unreacted sec-butyl acetate and sec-butyl alcohol generated after the reaction from the tower top, and carrying out normal-pressure or reduced-pressure flash evaporation to separate acetate generated after the reaction from a tower bottom fraction, wherein the alcohol is alcohol having a general formula of R(OH)n and/or polyol alkylether having at least one hydroxy group, R is a C5-C20 n-valence alkyl group, a C5-C20 n-valence alkenyl group, a C5-C12 n-valence cycloalkyl group or a C7-C20 n-valence aryl group, and n is an integer in a range of 1-5. The method has the advantages of high conversion rate of the alcohol as a reaction raw material, and high acetate selectivity.
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Paragraph 0047; 0048; 0049; 0050
(2017/01/26)
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- A simple acetylation of alcohols using ZnO nanopowder synthesized by microwave irradiation
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An efficient and selective method for acetylation of alcohols using ZnO nanopowder is described. In this method, alcohols are refluxed with a mixture of CH3COOH in the presence of catalytic amounts of ZnO nanopowder to afford their corresponding esters in good yields. This methodology is highly efficient for various structurally different alcohols: 1°, 2°, 3°. The prepared nano zinc oxide used in acetylation of alcohols which in comparison to ordinary ZnO has apparent advantages in promoting the yields of product formation.
- Javaherian, Mohammad,Sabzi, Hashem Eskandari
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p. 631 - 634
(2014/06/23)
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- Tris(pentafluorophenyl)borane catalyzed acylation of alcohols, phenols, amines, and thiophenols under solvent-free condition
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The acylation of alcohols, phenols, amines, and thiophenols was accomplished with 0.5 mol % of tris(pentafluorophenyl)borane [B(C 6F5)3] at ambient temperature under solvent-free condition. Major advantages of this method include high yield, short reaction time, simple procedure, compatibility with sensitive protecting groups as well as other functional groups, absence of racemization of optical active compounds, and epimerization of sugars.
- Prajapti, Santosh Kumar,Nagarsenkar, Atulya,Babu, Bathini Nagendra
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p. 1784 - 1787
(2014/03/21)
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- Rice husk: Introduction of a green, cheap and reusable catalyst for the protection of alcohols, phenols, amines and thiols
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A mild, efficient and eco-friendly protocol for the chemoselective protection of benzylic and primary and less hindered secondary aliphatic alcohols and phenols as trimethylsilyl ethers and different types of amines as N-tert-butylcarbamates is developed using rice husk (RiH) as the catalyst. This reagent is also able to catalyze the acetylation of alcohols, phenols, thiols and amines with acetic anhydride. Easy work-up, relatively short reaction times, excellent yields and low cost, availability and reusability of the catalyst are the striking features of this methodology, which can be considered to be one of the best and general methods for the protection of alcohols, phenols, thiols and amines. In addition, the use of a green reagent in the above-mentioned reactions results in a reduction of environmental pollution and of the cost of the applied methods.
- Shirini, Farhad,Akbari-Dadamahaleh, Somayeh,Mohammad-Khah, Ali,Aliakbar, Ali-Reza
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p. 164 - 170
(2014/03/21)
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- Rice husk ash: A new, cheap, efficient, and reusable reagent for the protection of alcohols, phenols, amines, and thiols
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Amild, efficient, and eco-friendly protocol for the protection of alcohols and phenols as trimethylsilyl ethers has been developed using rice husk ash as a reagent. This reagent is also able to catalyze the acetylation of alcohols, phenols, thiols, and amines with acetic anhydride. All reactions were performed under mild conditions in good to high yields. Copyright
- Shirini,Akbari-Dadamahaleh, Somayeh,Mohammad-Khah, Ali
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p. 577 - 586
(2014/06/09)
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- Poly(N-vinylimidazole) as an efficient catalyst for acetylation of alcohols, phenols, thiols and amines under solvent-free conditions
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Poly(N-vinylimidazole) is able to promote instantaneous quantitative acetylation of a variety of functionalized alcohols, phenols, thiols and amines with acetic anhydride at room temperature under solvent-free conditions. This new method consistently has excellent yields and the catalyst can be reused and recovered several times. Furthermore, the reaction can even be carried out on a larger scale. The Royal Society of Chemistry.
- Khaligh, Nader Ghaffari
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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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- L-pyrrolidine-2-carboxylic acid-4-hydrogen sulfate (supported on silica gel) as a new and efficient catalyst for acylation of alcohols, phenols and amines under solvent-free conditions
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In the present work, L-pyrrolidine-2-carboxylic acid-4-hydrogen sulfate, supported on silica gel was prepared and characterized by Mass spectroscopy, 1H NMR, 13CNMR, FT IR and elemental analysis (CHN) methods. This heterogenized catalyst can be used as an efficient catalyst for the acylation of alcohols, phenols, and amines with acetic anhydride under mild and solvent-free conditions. Simple work-up, stability of the catalyst, nontoxicity and good to high yields are the advantages of this work.
- Hajjami, Maryam,Ghorbani-Choghamarani, Arash,Khani, Zahra
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p. 324 - 329
(2013/07/26)
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- Solvent-free acetylation and tetrahydropyranylation of alcohols catalyzed by recyclable sulfonated ordered nanostructured carbon
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Rapid and practical green acetylation and tetrahydropyranylation routes of structurally diverse alcohols and phenols were applied under solvent-free reaction conditions providing excellent yields, using catalytic amounts of environmentally friendly sulfonated ordered nanoporous carbon (CMK-5-SO 3H). Non-toxic nature of the catalyst, its easy handling, recovery and reusability, and the absence of any solvent characterize the presented procedures as efficient methods. These procedures provide methods for the separation of the product by simple filtration.
- Zareyee, Daryoush,Alizadeh, Parastoo,Ghandali, Mohammad S.,Khalilzadeh, Mohammad A.
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p. 713 - 721
(2013/07/26)
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- Investigation of steapsin lipase for kinetic resolution of secondary alcohols and synthesis of valuable acetates in non-aqueous reaction medium
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In present study, the application of steapsin lipase (as a biocatalyst) was investigated for kinetic resolution of secondary alcohols (1-phenyl ethanol and their derivatives) using vinyl acetate as an activated acyl donor. The enzymatic protocol was optimized for various reaction parameters such as effect of the molar ratio, solvent, temperature, time and biocatalyst loading to obtain best reaction conditions. On optimization, developed enzymatic methodology provided considerable enantiomeric excess of the product (up to 92% ee) at 55 °C in n-hexane as a solvent. Furthermore using the developed protocol, synthesis of several industrially important acetates was successfully achieved with excellent yield (up to 99%). During acetate synthesis, the biocatalyst was remarkably reused for eight consecutive recycles without any significant loss in its catalytic activity. This revealed the good potential of steapsin lipase for application in organic solvents.
- Dhake, Kishor P.,Deshmukh, Krishna M.,Wagh, Yogesh S.,Singhal, Rekha S.,Bhanage, Bhalchandra M.
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experimental part
p. 15 - 23
(2012/06/29)
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- Preparation, characterization and use of poly(4-vinylpyridinium) perchlorate as a new, efficient, and versatile solid phase catalyst for acetylation of alcohols, phenols and amines
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Poly(4-vinylpyridine) perchlorate, is a supported, recyclable, eco-benign catalyst for the reaction acetylation of structurally diverse alcohols, phenols and amines at room temperature under solvent-free conditions. The catalyst was studied by FT-IR, X-ray diffraction, Scanning Electron Microscope and Thermo-gravimetric Analyses. All the products were extensively characterized by 1H NMR, FT-IR, GC-MS and melting point analyses. The catalyst can be recovered and reused without loss of activity. The work-up of the reaction consists of a simple filtration, followed by concentration of the crude product and purification. It is important to point out that a large-scale reaction is possible using a same amount of catalyst.
- Khaligh, Nader Ghaffari
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- Highly efficient solvent-free acetylation of alcohols with acetic anhydride catalyzed by recyclable sulfonic acid catalyst (SBA-15-Ph-Pr-SO3H)- An environmentally benign method
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The catalytic activity of highly thermal stable, hydrophobic, and complete heterogeneous propylsulfonic acid functionalized nanostructured SBA-15 for excellent acetylation of alcohols and phenols with acetic anhydride at ambient temperature in solvent-free conditions was examined under environmentally benign reaction conditions. The salient features of this protocol are the absence of solvent, a green experimental procedure, and simple reusability of the catalyst (at least five reaction cycles).
- Zareyee, Daryoush,Ghadikolaee, Abdollah Razaghi,Khalilzadeh, Mohammad A.
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experimental part
p. 464 - 468
(2012/06/16)
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- Silica chloride and boron sulfonic acid as solid acid catalysts in preparation of ethers and esters under solvent-free condition
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Boron sulfonic acid was easily prepared from the reaction of boric acid and chlorosulfonic acid under solvent free condition. The prepared solid acid was supported on silica gel by simple grinding and used as efficient solid acid catalyst in the preparation of ethers from the aliphatic and aromatic alcohols. The ethers were prepared in high isolated yields and in lesser times. Silica chloride was prepared by refluxing of silica gel in thionyl chloride. The obtained solid acid was efficiently used for the conditions of alcohols to the corresponding ethers and acetyl esters in less reaction time and in high isolated yields.
- Elham, Sedighinia,Mozhgan, Zahed Sargoli
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experimental part
p. 1456 - 1458
(2012/01/06)
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- Hydroacetoxylation of olefins with acetic acid genetated in situ from vinyl acetate in the presence of ruthenium complexes
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Ruthenium complexes catalyze the decomposition of vinyl acetate releasing the acetic acid and its subsequent addition to linear and cyclic olefins.
- Khusnutdinov,Shchadneva,Khisamova,Dzhemilev
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experimental part
p. 155 - 160
(2011/05/03)
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- Comparative study of acetylation of alcohols and phenols with different acetylating agents using zinc chloride as catalyst under solvent free conditions at room temperature
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Efficient acetylation of 1°, 2° and 3°, benzylic alcohols and phenols under solvent free conditions at room temperature in presence of less toxic, easily available and in-expensive catalyst ZnCl2, using acetic anhydride or acetyl chloride as an acetylating agent. On comparative study of these two acetylating agents, the acetyl chloride seemed to be better acetylating agent.
- Yadav, Prakrati,Lagarkha, Rekha,Balla, Zahoor Ahmad
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experimental part
p. 5155 - 5158
(2012/07/28)
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- Retro-claisen condensation with FeIII as catalyst under solvent-free conditions
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An iron(III) salt catalyzed retro-Claisen condensation between an alcohol and a 1,3-diketone was investigated. The mechanism involves the formation of a metal-induced sixmembered cyclic transition state and cleavage of the C sp2-Csp3 bond. Regioselective esterification and one-pot couversion of silyl ethers into esters with good yields was observed. Simple reaction conditions, high yields, and broad scope of the reaction illustrate the good synthetic utility of this method.
- Rao, Chitturi Bhujanga,Rao, Dasireddi Chandra,Babu, Dokuburra Chanti,Venkateswarlu, Yenamandra
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supporting information; experimental part
p. 2855 - 2859
(2010/08/05)
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- Dual behavior of alcohols in iodine-catalyzed esterification under solvent-free reaction conditions
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The dual behavior phenomenon of alcohols in iodine-catalyzed esterification under solvent-free reaction conditions (SFRCs) is described; the governing factor is the stability of the carbonium ion generated from the alcohol; high concentration reaction conditions (HCRCs) or dilute solutions are much less suitable. In the case of benzylic alcohols, loss of optical activity was noted, whereas alkyl alcohols furnished a product with retention of stereochemistry.
- Jereb, Marjan,Vra?i?, Dejan,Zupan, Marko
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scheme or table
p. 2347 - 2352
(2009/09/06)
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- NaIO4-KI-NaN3 as a new reagent system for C-H functionalization in hydrocarbons
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The NaIO4-KI-NaN3 combination has been found to be an efficient, reliable, and inexpensive reagent system for mono- and 1,2-difunctionalization of hydrocarbons via C-H bond activation to afford vicinal azido- and acetoxy iodinations of cyclic hydrocarbons.
- Chouthaiwale, Pandurang V.,Suryavanshi, Gurunath,Sudalai, Arumugam
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scheme or table
p. 6401 - 6403
(2009/04/06)
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- Transesterification/Acylation of Secondary Alcohols Mediated by N-Heterocyclic Carbene Catalysts
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N-Heterocyclic carbenes (NHC) are efficient catalysts for transesterification/acylation reactions involving secondary alcohols. The catalytic transformations are carried out employing low catalyst loadings in convenient reaction times at room temperature.
- Singh, Rohit,Kissling, Rebecca M.,Letellier, Marie-Anne,Nolan, Steven P.
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p. 209 - 212
(2007/10/03)
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- Meerwein-Ponndorf-Verley-type reductive acetylation of carbonyl compounds to acetates by lanthanide complexes in the presence of isopropenyl acetate
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Meerwein-Ponndorf-Verley-type reductive acetylation of carbonyl compounds to acetates was successfully carried out in the presence of isopropenyl acetate under the influence of a catalytic amount of Ln(O(i)Pr)3 at room temperature. Various carbonyl compounds were converted into the corresponding acetates in fair to good yields. (C) 2000 Elsevier Science Ltd.
- Nakano, Yasushi,Sakaguchi, Satoshi,Ishii, Yasutaka
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p. 1565 - 1569
(2007/10/03)
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- Catalytic esterification of alcohols, carboxylic acids and transesterification reactions with cerium(IV) triflate
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Esterification reactions of alcohols with acetic, chloroacetic, trifluoroacetic, propionic, stearic, and benzoic acids were catalyzed with Ce(OTf)4 in a solvent or under solvent-free conditions with high yields. The formylation and acetylation of primary and secondary alcohols were also easily achieved in ethyl formate and ethyl acetate. A high retention of the configuration was observed in the acetylation and formylation of (-)-menthol.
- Iranpoor, Nasser,Shekarriz, Marzieh
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p. 455 - 458
(2007/10/03)
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- Nucleophilic Metal Complexes as Acylation Catalysts: Solvent-dependent Switch Mechanisms Leading to the First Catalyzed Staudinger Reaction
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(Matrix Presented) Catalytic acylation using complex transition metal salts MCo(CO)4 is demonstrated. Surprisingly, a solvent-dependent mechanistic "switch" results in a Lewis acid-based acylation mechanism in nonpolar media and a nucleophilic mechanism in polar organic media. These observations lead to the first example of a catalyzed Staudinger reaction to form β-lactams.
- Wack, Harald,Drury III, William J.,Taggi, Andrew E.,Ferraris, Dana,Lectka, Thomas
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p. 1985 - 1988
(2008/02/11)
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- Bromide ions and methyltrioxorhenium as cocatalysts for hydrogen peroxide oxidations and brominations
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Oxidation of alcohols by hydrogen peroxide is negligible; even when catalyzed by methyltrioxorhenium (MTO), the process requires a long reaction time. The addition of a catalytic quantity of bromide ions, as HBr or NaBr, greatly enhances the rate. Some of the reactions were carried out on a larger scale in glacial acetic acid, and others at kinetic concentrations. The data establish that Br2 is the active oxidizing agent in the system, because the catalytic rates under suitable circumstances match those for the independently measured Br2 reaction with alcohol (benzyl alcohol, in particular). At much lower levels of MTO, however, Br2 formation plays a role in the kinetics. Certain other reluctant transformations are conveniently carried out with the MTO/H2O2/Br- combination: aldehydes to methyl esters; 1,3-dioxolanes to glycol monoesters; and ethers (with cleavage) to ketones (mostly), but in fair yield only. When Br- was used in stoichiometric quantity, certain bromination reactions occur. Thus, phenyl acetylenes (PhC2R, R = H, Me, Ph) are converted to dibromoalkenes that are entirely or largely formed as the trans isomer, and phenols are brominated. The latter reaction shows the preference para > ortho > meta. Kinetic studies of benzyl alcohol oxidation with MTO/H2O2Br- were carried out in aqueous solution. With sufficient (normal) levels of MTO, the rate constant for the formation of benzaldehyde agreed with the independently determined value for Br2 + PhCH2OH, k = 4.3 x 10-3 L mol-1 s-1 at 25.0 °C; for sec- phenethyl alcohol, k = (9.8 ± 0.4) x 10-3 L mol-1 s-1. Bromine is formed from the known oxidation of Br- with H2O2, catalyzed by MTO. This reaction results in BrO-/HBOr, which is then rapidly converted to Br2. However, with substantially lower concentrations of MTO, the buildup of benzaldehyde is ca. 4-fold slower, reflecting the diminished rate of Br- oxidation.
- Espenson,Zhu,Zauche
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p. 1191 - 1196
(2007/10/03)
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- Origin of the Enantioselectivity of Lipases Explained by a Stereo-Sensing Mechanism Operative at the Transition State
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The stereoelectronic considerations and the molecular modeling using an X-ray structure of Rhizomucor miehei lipase suggested that the lipase-catalyzed reactions proceed under the stereoelectronic control. This suggestion was supported by the semiempirical MO (MNDO-PM3) calculations carried out on the imidazole-catalyzed transesterification as a model reaction. The stereoelectronic effect operates at the transition state (TS) more effectively than at the tetrahedral intermediate (THI). The stabilization energy due to the stereoelectronic effect operating at the TS was estimated to be ca. 5 kcal mol-1. The enantioselectivities for 1-phenylethanol, l-phenyl-2-propanol, and 1-cyclohexylethanol were estimated in terms of the lipase-induced strain caused at the TS. A TS model generally applicable to chiral secondary alcohols is proposed. The kinetic study supported the TS model. The result that the enantioselectivity in the lipase-catalyzed transesterifications arises from the difference in Vmax between the two enantiomers rather than from the difference in Km indicates that the ability of Upases to discriminate between the enantiomers at the TS is high, while the ability to recognize the chirality in the binding step is poor. Furthermore, the difference in Vmax between the enantiomers was found to result not from the enhanced reactivity of the (R)-enantiomers but from the reduced reactivity of the (S)-enantiomers.
- Ema, Tadashi,Kobayashi, Juka,Maeno, Soichi,Sakai, Takashi,Utaka, Masanori
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p. 443 - 453
(2007/10/03)
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- Selective acetylation of primary alcohols: Acetyl and formyl transfer reactions with copper(II) salts
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The efficient esterification of primary and secondary alcohols in acetic acid was achieved in the presence of Cu(NO3)2. 3H20 in high yields. Selective acetylation of primary in the presence of secondary hydroxyl groups in excellent yields were performed in EtOAc. Formylation of primary and secondary alcohols was also achieved easily in ethyl formate. High retention of configuration was observed in the acetylafion and formylation of (-) menthol in the presence of Cu(NO3)2. 3H20 and Cu(OAC)2. H2O.
- Iranpoor,Firouzabadi,Zolfigol
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p. 1923 - 1934
(2007/10/03)
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- Synthesis of 2-Substituted Bicyclopentanes from Bicyclohexan-2-one
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Bicyclohexan-2-one (1) was converted into the 3-diazo derivative (4) wich was ringcontracted thermally to give a variety of amides and esters of bicyclopentane-2-carboxylic acid as exo- and endo-stereoisomers.Conversion of the acids into the corresponding methyl ketones and then Baeyer-Villiger reaction has led to endo- and exo-bicyclopentan-2-yl acetates wich differed markedly in solvolytic reactivity.
- Brook, Peter R.,Brophy, Bernard V.
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p. 2509 - 2514
(2007/10/02)
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- REACTION OF ORGANOBORANES WITH LEAD(IV) ACETATE AZIDE. A SYNTHESIS OF AZIDOALKANES FROM ALKENES VIA HYDROBORATION.
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Trialkylboranes prepared from alkenes via hydroboration react with lead(IV) acetate azide in dichloromethane at minus 25 degree C to form the corresponding azidoalkanes in a one-pot manner. One of two of the alkyl groups of trialkylboranes are utilized in the reaction. For example, 1-azidohexane is afforded from 1-hexene in 50% yield based on the alkene employed.
- Masuda,Hoshi,Arase
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p. 1026 - 1030
(2007/10/02)
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- REACTION OF TRIALKYLBORANE WITH 1-ALKYNE AND LEAD(IV) ACETATE, A NEW REGIOSPECIFIC AND STEREOSPECIFIC ONE-POT SYNTHESIS OF ENOL ACETATES
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In the reaction of trialkylborane with 1-alkyne and lead(IV) acetate in hexane, one of the alkyl groups of trialkylborane migrated to the terminal carbon atom of the triple bond, giving regiospecifically an internal enol acetate and an internal alkyne as the main reaction products.The former compound had (Z)-configuration.
- Masuda, Yuzuru,Hoshi, Masayuki,Arase, Akira
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p. 413 - 416
(2007/10/02)
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