- Insight into the Mechanism of the Acylation of Alcohols with Acid Anhydrides Catalyzed by Phosphoric Acid Derivatives
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Insight into the mechanism of a safe, simple, and inexpensive phosphoric acid (H3PO4)-catalyzed acylation of alcohols with acid anhydrides is described. The corresponding in situ-generated diacylated mixed anhydrides, unlike traditionally proposed monoacylated mixed anhydrides, are proposed as the active species. In particular, the diacylated mixed anhydrides act as efficient catalytic acyl transfer reagents rather than as Br?nsted acid catalysts simply activating acid anhydrides. Remarkably, highly efficient phosphoric acid (1-3 mol %)-catalyzed acylation of alcohols with acid anhydrides was achieved and a 23 g scale synthesis of an ester was demonstrated. Also, phosphoric acid catalyst was effective for synthetically useful esterification from carboxylic acids, alcohols, and acid anhydride. Moreover, with regard to recent developments in chiral 1,1′-bi-2-naphthol (BINOL)-derived phosphoric acid diester catalysts toward asymmetric kinetic resolution of alcohols by acylation, some phosphate diesters were examined. As a result, a 31P NMR study and a kinetics study strongly supported not only the acid-base cooperative mechanism as previously proposed by other researchers but also the mixed anhydride mechanism as presently proposed by us.
- Hayashi, Hiroyuki,Yasukochi, Shotaro,Sakamoto, Tatsuhiro,Hatano, Manabu,Ishihara, Kazuaki
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p. 5197 - 5212
(2021/04/12)
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- Selective biocatalytic hydroxylation of unactivated methylene C-H bonds in cyclic alkyl substrates
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The cytochrome P450 monooxygenase CYP101B1 from Novosphingobium aromaticivorans selectively hydroxylated methylene C-H bonds in cycloalkyl rings. Cycloketones and cycloalkyl esters containing C6, C8, C10 and C12 rings were oxidised with high selectively on the opposite side of the ring to the carbonyl substituent. Cyclodecanone was oxidised to oxabicycloundecanol derivatives in equilibrium with the hydroxycyclodecanones.
- Sarkar, Md Raihan,Dasgupta, Samrat,Pyke, Simon M.,Bell, Stephen G.
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p. 5029 - 5032
(2019/05/21)
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- Pyridinium saccharinate salts as efficient recyclable acylation catalyst: A new bridge between heterogeneous and homogeneous catalysis
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It is important to find a way for separation of concerned chemicals from product mixture after reaction, in order to avoid spreading harmful chemicals to society. The homogeneous nature of DMAP-catalyzed acylation still suffers from the problems of catalyst separation and/or residual DMAP contamination. DMAP causes acute dermal toxicity, whereas the corresponding DMAP salt exhibits only slight irritation to the skin. Very recently, we found that the DMAP saccharinate salt is also great recyclable catalyst, whose acylation of alcohols has been successfully and effectively carried out 10 times without loss in activity. This report covers our comprehensive studies on using the pyridinium saccharinate salts as efficient recyclable acylation catalysts including 4-N,N-dimethylaminopyridinium saccharinate (A), 4-(1-pyrrolidinyl) pyridinium saccharinate (B), 2-N,N-dimethylaminopyridinium saccharinate (C), and pyridinium saccharinate (D). Their structure and reactivity have been studied. The salts A, C, and D contain very interesting seven-membered synthon showing multiple H-bonding interactions for pair of pyridinium cation and saccharinate anion in the solid state. The salt B exhibits H-bonding interaction of N(sac) ... H-N(py) in the solid state, instead of seven-membered synthon. The catalytic reactivity studies show that salts A and B are both very effective, with salt B even better in reactivity, and are both recyclable in the esterification of a variety of alcohols, under solvent-free and base-free conditions at room temperature.
- Lu, Norman,Chang, Wei-Hsuan,Wei, Rong-Jyun,Fang, Yung-Cheng,Han, Tu-Wen,Wang, Guo-Quan,Chang, Jia-Yaw,Wen, Yuh-Sheng,Liu, Ling-Kang
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p. 3468 - 3476
(2016/06/06)
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- Tribromoisocyanuric acid (TBCA) as a mild and metal free catalyst for the acetylation and formylation of hydroxyl groups under solvent free conditions
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A convenient approach for acetylation and formylation of various types of alcohols and phenols with acetic anhydride and formic acid in the presence of Tribromoisocyanuric acid (TBCA) as catalyst is reported. The reactions were carried out under solvent-free condition and in good to high yields at room temperature. This present method is featured with relatively mild reaction conditions, simple operation, broad substrate scope, clean work-up, short reaction times, good to high yields, excellent selectivity and also avoids tedious purifications and the use of toxic reagents.
- Hekmatian, Zahra,Khazaei, Ardeshir
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p. 1565 - 1570
(2016/01/26)
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- Synthesis, characterization and application of poly(N,N'-dibromo- Nethylnaphthyl-2,7-disulfonamide) as an efficient catalyst for the acetylation and deacetylation reactions
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In this work, a novel polymer namely poly(N,N'-dibromo-N-ethylnaphthyl-2,7- disulfonamide) (PBNS) is synthesized and characterized by studying its IR, 1H NMR, 13C NMR and thermal gravimetric analysis (TGA). This polymer is utilized as a highly efficient, heterogeneous and recyclable N-bromo reagent to catalyze acetylation of various compounds such as alcohols, phenols, thiol and amine with acetic anhydride under solvent-free conditions, and also it worthily catalyzes deacetylation of acetate esters in aqueous media.
- Khazaei, Ardeshir,Saednia, Shahnaz,Roshani, Liela,Kazem-Rostami, Masoud,Zare, Abdolkarim
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p. 159 - 167
(2014/05/20)
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- RECYCLABLE CATALYSTS FOR ESTERIFICATION OR ACYLATION OF ALCOHOLS
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A compound is useful as a recyclable catalyst for esterification or acylation of alcohols and consists of saccharine and a compound comprising a pyridine moiety. In addition, also a method of preparing the compound and an ester synthesis method using the compound are introduced.
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Page/Page column 3
(2012/07/28)
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- A salt made of 4-N,N-dimethylaminopyridine (DMAP) and saccharin as an efficient recyclable acylation catalyst: A new bridge between heterogeneous and homogeneous catalysis
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Here, we report insights into the new recyclable catalyst 1, (DMAP·saccharin). The DMAP·saccharin-catalysed acylation of alcohols has been successfully carried out more than 8 times. Only 1 mol% of catalyst 1 efficiently promotes acylation with almost equimolar amounts of acid anhydrides, under both base-free and solvent-free conditions.
- Lu, Norman,Chang, Wei-Hsuan,Tu, Wen-Han,Li, Chieh-Keng
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supporting information; experimental part
p. 7227 - 7229
(2011/09/12)
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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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- Ligand-assisted rate acceleration in lanthanum
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The transesterification of an equimolar mixture of carboxylic esters and primary (1°), secondary (2°), and tertiary (3°) alcohols in hydrocarbon solvents was promoted with high efficiency by a lanthanum(III) complex, which was prepared in situ from lanthanum (III) isopropoxide (1 mol %) and 2-(2-methoxyethoxy)ethanol (2 mol %). The present La(III) catalyst was highly effective for the chemoselective transesterification in the presence of competitive 1°-and 2°-amines. Remarkably, esters were obtained in good to excellent yields as colorless materials without an inconvenient workup procedure.
- Hatano, Manabu,Furuya, Yoshiro,Shimmura, Takumi,Moriyama, Katsuhiko,Kamiya, Sho,Maki, Toshikatsu,Ishihara, Kazuaki
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supporting information; experimental part
p. 426 - 429
(2011/04/15)
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- Fluorous 4-N,N-dimethylaminopyridine (DMAP) salts as simple recyclable acylation catalysts
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The use of an easily accessible fluorous salt of DMAP, 1-R, as an active and recyclable acylation catalyst, under simple conditions has been reported. The recyclability of organic- and metal-based catalysts is of prime interest for the development of sustainable synthesis processes. The alcohol and the anhydride were mixed in a 10 mL round-bottomed flask and 1-R was added. The DMAP-catalyzed esterification reaction of an alcohol is performed in nonpolar solvents with an anhydride as the acyl donor, in the presence of a base in stoichiometric amounts. The simplicity of the process (readily accessible catalyst, easy to handle and to recover) makes it an attractive alternative for cleaner and safer acylation reactions, which could be used with asymmetric dialkylaminopyridines, or in other transformations, such as the Baylis Hillman reaction.
- Vuluga, Daniela,Legros, Julien,Crousse, Benoit,Bonnet-Delpon, Daniele
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supporting information; experimental part
p. 1776 - 1779
(2010/06/14)
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- N,N′-dibromo-N,N′-1,2-ethanediylbis(benzene sulfonamide) as an efficient catalyst for acetylation and formylation of alcohols under mild conditions
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An efficient method for the acylation and formylation of alcohols and phenols by using an acylating/formylating agent (acetic anhydride and formic acid) in the presence of a catalytic amount of N,N′-dibromo-N,N′-1, 2-ethanediylbis(benzene sulfonamide) under mild and solvent-free conditions at room temperature in good to excellent yields is described. The use of protic acids and metal Lewis acids is avoided.
- Khazaei, Ardeshir,Rostami, Amin,Rosta, Zahra,Alavi, Ali
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experimental part
p. 181 - 186
(2010/04/05)
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- Potassium fluoride assisted selective acetylation of alcohols with acetic acid
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Potassium fluoride promotes the acetylation of primary and secondary alcohols with acetic acid in excellent yield. Phenols are not affected under this reaction conditions. The groups like double bond, chloro, methoxy, benzyloxy, thiol, and nitro remain unaffected.
- Bosco, J. W. John,Raju, B. Rama,Saikia, Anil K.
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p. 2849 - 2855
(2007/10/03)
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- Cleavage of 2-methoxyethoxymethyl ethers catalyzed by cerium(IV) ammonium nitrate (CAN) in acetic anhydride
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The reactions of 2-methoxyethoxymethyl (MEM) ethers 1 with a catalytic amount of cerium(IV) ammonium nitrate (CAN) in acetic anhydride gave the corresponding mixed acetal esters 2 and acetates 3.
- Tanemura, Kiyoshi,Suzuki, Tsuneo,Nishida, Yoko,Satsumabayashi, Koko,Horaguchi, Takaaki
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p. 1012 - 1013
(2007/10/03)
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- Odor-structure relationships using fluorine as a probe
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Eight ethers, nine esters and one ketone were submitted to a systematic structural variation by replacing a hydrogen atom in the vicinity of the oxofunction by fluorine and methyl. As long as steric factors dominate, a fluorine substituent alters the olfactory properties of the parent compound much less than a methyl substituent does. However, if it occupies a position adjacent to a carbonyl group, the halogen may more profoundly affect the odor perception, presumably as a consequence of conformational changes. (C) 2000 Elsevier Science Ltd.
- Michel, Dominique,Schlosser, Manfred
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p. 4253 - 4260
(2007/10/03)
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- OXIDATIVE SUBSTITUTION OF PhTe AND PhSe MOIETIES IN ALKYL PHENYL TELLURIDES AND SELENIDES LEADING TO ESTERS AND ALCOHOLS
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Oxidation of alkyl phenyl tellurides and/or selenides with sodium periodate (NaIO4) in aqueous acetic acid or with metachloroperbenzoic acid (MCPBA) in N,N-dimethylformamide or N,N-dimethylacetamide affords a mixture of the corresponding alkyl esters (acetates or formates) and/or alcohols in 20-94percent yield under mild conditions (at 20-80 deg C for 0.5-24 h).
- Hirai, Yasuyuki,Ohe, Kouichi,Toshimitsu, Akio,Uemura, Sakae
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p. 173 - 176
(2007/10/02)
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- RADICAL CHEMISTRY BASED ON (+)-CIS-PINONIC ACID
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The capture of the radical from decarboxylation of (+)-cis-pinonic acid has been investigated.Efficient trapping agents give good yields of desired products.Less efficient trapping conditions permit undesired opening of the four-membered ring.
- Barton, Derek H. R.,Ozbalik, Nubar,Schmitt, Martine
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p. 3263 - 3266
(2007/10/02)
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- A Convenient Procedure for the Reductive Deselenization of Selenides with Nickel Boride
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Nickel boride, readily produced in situ from nickel chloride hexahydrate and sodium borohydride, efficiently reduces selenides to hydrocarbons under mild conditions.
- Back, Thomas G.
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p. 1417 - 1418
(2007/10/02)
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