- Lipase-mediated selective acetylation of primary alcohols in ethyl acetate
-
An environmental friendly process to selectively acetylate primary alcohols was demonstrated. The esterification process consists of treatment of a primary alcohol in the presence of immobilized C. antarctica lipase (Novozyme-435) in ethyl acetate at room temperature. Primary alcohols were acetylated in the presence of secondary alcohols and phenols.
- de Souza, Ernane C.,Romero-Ortega, Moises,Olivo, Horacio F.
-
supporting information
p. 287 - 290
(2017/12/29)
-
- Decarboxylative Csp3-Csp3 coupling for benzylation of unstable ketone enolates: Synthesis of: P -(acylethyl)phenols
-
A new decarboxylative Csp3-Csp3 coupling approach for the benzylation of ketone enolates has been developed. A variety of raspberry ketone derivatives were conveniently synthesized in good to excellent yields under mild conditions. A crossover reaction shed light on the mechanism of this tandem reaction.
- Wang, Sasa,Chen, Xinzheng,Ao, Qiaoqiao,Wang, Huifei,Zhai, Hongbin
-
p. 9454 - 9457
(2016/07/29)
-
- Syntheses of methylated catechins and theaflavins using 2-nitrobenzenesulfonyl group to protect and deactivate phenol
-
An efficient and versatile synthetic method for labile polyphenols was established using 2-nitrobenzenesulfonate (Ns) as a protecting group for phenol. This methodology provides regio-and stereoselective access to a range of methylated catechins, such as methylated epigallocatechin gallates, that are not readily available from natural sources. In addition, biomimetic synthesis of theaflavins from catechins was accomplished using Ns protection to minimize undesired side reactions of electron-rich aromatic rings during oxidation, enabling construction of the complex benzotropolone core in a single-step oxidative coupling reaction. Availability of these compounds will aid detailed structure-biological activity relationship studies of catechins.
- Asakawa, Tomohiro,Kawabe, Yusuke,Yoshida, Atsushi,Aihara, Yoshiyuki,Manabe, Tamiko,Hirose, Yoshitsugu,Sakurada, Asuka,Inai, Makoto,Hamashima, Yoshitaka,Furuta, Takumi,Wakimoto, Toshiyuki,Kan, Toshiyuki
-
p. 299 - 312
(2016/05/09)
-
- Gastrodin production process
-
Disclosed is a gastrodin production process comprising the preparation of acetoxymethyl phenol, the preparation of pentacetyl gastrodin, and the preparation and refining of gastrodin, including: stirring hydroxybenzyl alcohol, glacial acetic acid and ethy
- -
-
Paragraph 0035-0040; 0043
(2017/01/17)
-
- Efficient approach for the chemoselective acetylation of alcohols catalyzed by a novel metal oxide nanocatalyst CuO-ZnO
-
A new method has been developed for the chemoselective acetylation of alcohols with acetic anhydride in the presence of phenols using a novel, recyclable CuO-ZnO nanocatalyst. The catalyst was synthesized using the co-precipitation method and characterized by N2 adsorption-desorption, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersion scanning analyses. Furthermore, this catalyst could be recycled up to six times without significant loss in its activity.
- Albadi, Jalal,Alihosseinzadeh, Amir,Mardani, Mehdi
-
p. 308 - 313
(2015/09/28)
-
- Kinetics of self-immolative degradation in a linear polymeric system: Demonstrating the effect of chain length
-
We describe here a study demonstrating that the degradation time of self-immolative linear polymers is dependent on chain length. These materials are unique relative to most degradable polymers, in that they undergo end-to-end depolymerization in response to the cleavage of an end-cap. Although one of their cited attributes is a dependence of their degradation time on chain length, no conclusive study has been conducted to demonstrate and study this effect. In this work, using a linear self-immolative polymer backbone derived from alternating 4-hydroxybenzyl alcohol and N,N′-dimethylethylenediamine based spacers, we show that there is a proportional relationship between chain length and depolymerization time. This is first accomplished using a series of oligomers synthesized using a convergent, iterative route and then applied to the polydisperse case on a set of polymers displaying varying molecular weights. We also report the first development and validation of a self-immolative degradation model relating monomer kinetics to polymer degradation and show its application in explaining oligomeric and polymeric degradation profiles.
- McBride, Ryan A.,Gillies, Elizabeth R.
-
p. 5157 - 5166
(2013/07/26)
-
- Characterization of novel Cs and K substituted phosphotungstic acid modified MCM-41 catalyst and its catalytic activity towards acetylation of aromatic alcohols
-
TheMCM-41 supported Cs2.5H0.5PW12O 40 and K2.5H0.5PW12O40 salts were synthesized by incipient wetness impregnation method. The solids were characterized by N2 adsorption-desorption isotherms, FTIR, XRD, and temperature programmed desorption, etc. This catalyst has been found to exhibit excellent activity for acetylation of phenolic compounds. The catalyst is stable and reusable giving 96% conversion with 100% selectivity towards acetate products. Indian Academy of Sciences.
- Rana, Surjyakanta,Mallick, Sujata,Rath, Dharitri,Parida
-
p. 1117 - 1125
(2013/03/13)
-
- H6GeMo10V2O40·16H 2O nanoparticles prepared by hydrothermal method: A new and reusable heteropoly acid catalyst for highly efficient acetylation of alcohols and phenols under solvent-free conditions
-
A new Keggin-type heteropoly acid, namely decamolybdodivanadogermanic acid (H6GeMo10V2O40·16H 2O), with nanosized particles (5-8 nm), has been synthesized by a hydrothermal method and characterized by elemental analysis, thermogravimetric analysis (TGA), powder X-ray diffractometry (XRD), Fourier-transform infrared spectroscopy (FTIR), UV-Visible spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and potentiometric titration. H6GeMo10V2O40·16H 2O revealed high catalytic activity for acetylation of various alcohols and phenols with acetic anhydride at room temperature (298 ± 2 K) and under solvent-free conditions. The catalyst can be easily recovered and used repeatedly for five cycles with a slight loss of activity. The catalytic activity of H6GeMo10V2O40· 16H2O was higher than that of other Keggin-type heteropoly acids, such as H3PW12O40, H3PMo 12O40 and H4SiW12O40.
- Farhadi, Saeid,Zareisahamieh, Reza,Zaidi, Masoumeh
-
experimental part
p. 1323 - 1332
(2012/04/04)
-
- One-pot sequence for reductive-acetylation of carbonyl compounds with (N-methylimidazole)(tetrahydroborato)zinc complex
-
Reductive-acetylation of variety of aliphatic and aromatic aldehydes and ketones, α,β-unsaturated carbonyl compounds are examined efficiently with (N-methylimidazole)(tetrahydroborato)zinc complex, [Zn(BH4) 2(nmi)], under mild condition in THF at room temperature or reflux conditions. The corresponding acetates were obtained in excellent yields (90-98 %).
- Setamdideh, Davood,Khezri, Behrooz
-
experimental part
p. 5766 - 5772
(2012/07/28)
-
- Spinel-type zinc aluminate (ZnAl2O4) nanoparticles prepared by the co-precipitation method: A novel, green and recyclable heterogeneous catalyst for the acetylation of amines, alcohols and phenols under solvent-free conditions
-
Zinc aluminate (ZnAl2O4) nanoparticles with an average particle size of about 8 nm were easily prepared by the co-precipitation method using aqueous ammonia solution as the precipitating agent. This nanosized spinel-type oxide was characterized by TGA, XRD, FT-IR, TEM, and surface area measurement and used as the heterogeneous catalyst for the acetylation reaction. Efficient acetylation of various amines, alcohols and phenols was carried out over ZnAl2O4 nanoparticles using acetic anhydride and/or acetyl chloride as the acetylating agents at room temperature without the use of a solvent. The method is highly selective, allowing the alcoholic hydroxyl group to be protected while the phenolic hydroxyl group remains intact, and the amine group can be acetylated in the presence of the hydroxyl group. This method is fast and has a high yield. It is also clean, safe, cost effective, compatible with substrates that have other functional groups and very suitable for practical organic synthesis. In addition, the catalyst can be reused without significant loss of activity. Indeed, the catalytic activity of the ZnAl2O4 nanoparticles is higher than that of bulk ZnAl2O4.
- Farhadi, Saeid,Panahandehjoo, Somayeh
-
scheme or table
p. 293 - 302
(2010/09/04)
-
- METHOD FOR IDENTIFYING COMPOUNDS THAT ACT AS INSULIN-SENSITIZERS
-
The present invention relates to a method for identifying compounds that act as insulin-sensitizers. The method can include screening of test compounds in two assays of insulin sensitivity. This method can identify lead compounds for the treatment of disorders caused by insulin resistance to glucose uptake. This invention also includes methods for treating insulin resistance and related disorders.
- -
-
-
- Microwave-accelerated selective acylation of (hydroxyalkyl)phenols using acid chlorides
-
Highly selective acylation of the alcoholic hydroxy group can be achieved with (hydroxyalkyl)phenols carrying both alcoholic and phenolic hydroxyls by the use of the most common acylating agents, acid chlorides, under microwave irradiation. Copyright Tayl
- Miyazawa, Toshifumi,Yamamoto, Masato,Maeda, Yuki
-
experimental part
p. 1092 - 1099
(2009/09/06)
-
- Phosphomolybdic acid: Mild and efficient catalyst for acetylation of alcohols, phenols, and amines under solvent-free conditions
-
Phosphomolybdic acid (PMA) has been found to be a simple and efficient catalyst for the acetylation of alcohols, phenols, and amines. Acetylation reactions with acetic anhydride (1.0 equiv) proceed in excellent yield in the presence of a catalytic amount (0.2 mol%) of PMA at ambient temperature within a relatively short reaction time (10 min). Structurally diverse alcohols, phenols, and amines undergo acetylation under solvent-free conditions. Georg Thieme Verlag Stuttgart.
- Kadam, Santosh T.,Sung, Soo Kim
-
p. 267 - 271
(2008/12/22)
-
- Hydroxybenzyl or hydroxypyranonemethyl esters as tyrosinase inhibitors
-
Method for the preparation of ester compounds for use as skin brightening agents and compositions for brightening skin containing the ester compounds.
- -
-
Page/Page column 7
(2009/01/20)
-
- Molecular iodine catalyzed selective acetylation of alcohols with vinyl acetate
-
Molecular iodine is found to catalyze the acetylation of alcohols efficiently with vinyl acetate. The reaction is mild and selective with good to high yields. Molecular iodine displays significant functional group tolerance, being compatible with methoxy, double bonds, spiroketals, ketals and phenolic hydroxyl functions.
- Bosco, J.W. John,Agrahari, Aditya,Saikia, Anil K.
-
p. 4065 - 4068
(2007/10/03)
-
- Asymmetric synthesis of hydrobenzofuranones via desymmetrization of cyclohexadienones using the intramolecular Stetter reaction
-
Dearomatization of phenols followed by oxidation affords cyclohexadienyloxyacetaldehydes, which produce hydrobenzofuranones via asymmetric intramolecular Stetter reaction in good to excellent yield. Quaternary as well as up to three contiguous stereocenters may be formed in good to excellent enantioselectivities and high diastereoselectivities. Copyright
- Liu, Qin,Rovis, Tomislav
-
p. 2552 - 2553
(2007/10/03)
-
- Practical process for the air oxidation of cresols: Part A. Mechanistic investigations
-
The catalytic air oxidation of p-cresol and 2,6-di-tert-butyl-4- methylphenol to the corresponding benzaldehydes was investigated to determine the mechanism at work in these oxidation reactions. A number of intermediates and byproducts, mainly in the form of dimers, were observed during the course of the reactions, and their structures were elucidated by spectroscopic and chromatographic methods. The existence of these compounds in the reaction mixtures, and their proposed methods of formation, provided further insight into the mechanism involved in these oxidations.
- Barton, Benita,Logie, Catherine G.,Schoonees, Barbara M.,Zeelie, Bernard
-
-
- Potassium fluoride assisted selective acetylation of alcohols with acetic acid
-
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.
-
p. 2849 - 2855
(2007/10/03)
-
- Facile and selective deprotection of aryl acetates using sodium perborate under mild and neutral conditions
-
A variety of aryl acetates are cleaved to the corresponding phenols using sodium perborate in methanol under mild conditions (25°C). The effectiveness of this protocol is manifested in its tolerance of different functional groups and selectivity of deprotection towards aryl acetates whereas alkyl acetates are found to be unreactive under these reaction conditions.
- Bandgar, Babasaheb P.,Uppalla, Lavkumar S.,Sadavarte, Vaibhav S.,Patil, Suresh V.
-
p. 1273 - 1276
(2007/10/03)
-
- Chemoselective acetylation of alcohols, amines, and thiols without catalyst and solvent
-
Microwave induced rapid and selective acetylation of alcohols, amines and thiols with acetic anhydride was carried out under non-catalytic and solvent free conditions.
- Bandgar,Kasture,Kamble
-
p. 2255 - 2259
(2007/10/03)
-
- A mild procedure for rapid and selective deprotection of aryl acetates using natural kaolinitic clay as a reusable catalyst
-
A variety of aryl acetates are selectively cleaved to the corresponding phenols using natural kaolinitic clay in methanol under mild conditions (25°C).
- Bandgar,Uppalla,Sagar,Sadavarte
-
p. 1163 - 1165
(2007/10/03)
-
- Sulfurated borohydride exchange resin: Reductive cleavage of aryl acetates under mild conditions
-
A variety of aryl acetates are selectively cleaved to the corresponding phenols using sulfurated borohydride exchange resin in methanol at 25°C. Other sensitive groups present elsewhere in the molecule remain unaltered under these reaction conditions.
- Bandgar,Kamble
-
-
- Enzyme-catalyzed chemoselective transesterification reactions on hydroxymethylated phenolic compounds
-
The chemoselective capabilities of porcine pancreatic lipase (PPL) in tetrahydrofuran and Candida rugosa lipase (CRL) in diisopropyl ether have been investigated for selective acetylation and deacetylation of hydroxymethylated phenols and hydroxyaryl alky
- Parmar, Virinder S.,Prasad, Ashok K.,Pati, Hari N.,Kumar, Rajesh,Azim, Abul,Roy, Sucharita,Errington, William
-
p. 119 - 134
(2007/10/03)
-
- Microwave assisted selective cleavage of sulfonates and sulfonamides in dry media
-
A simple and efficient method for the cleavage of Sulfonates and Sulfonamides has been achieved for the first time under microwave irradiation conditions using KF-Al2O3.
- Sabitha, Gowravaram,Abraham, Sunny,Reddy, B. V. Subba,Yadav
-
p. 1745 - 1746
(2007/10/03)
-
- Lipase-catalysed chemoselective monoacetylation of hydroxyalkylphenols and chemoselective removal of a single acetyl group from their diacetates
-
It was demonstrated that Pseudomonas cepacia PS lipase adsorbed on Celite, has the ability to catalyse the chemoselective monoacetylation of various hydroxyalkylphenols or the chemoselective removal of a single acetyl group from the corresponding acetate.
- Allevi, Pietro,Ciuffreda, Pierangela,Longo, Alessandra,Anastasia, Mario
-
p. 2915 - 2924
(2007/10/03)
-
- Regio- and Chemo-selective Properties of Lipase from Candida cylindracea
-
Lipase from Candida cylindracea allows discrimination between the two connectively non-equivalent hydroxy groups in primary diols or their esters via acylation-hydrolysis, with high regioselectivity.The same technique is used to distinguish between hydroxy groups of different nature in phenolic compounds.
- Pedrocchi-Fantoni, Giuseppe,Servi, Stefano
-
p. 1029 - 1034
(2007/10/02)
-
- Bioreversible Protection for the Phospho Group: Chemical Stability and Bioactivation of Di(4-acetoxybenzyl) Methylphosphonate with Carboxyesterase
-
In contrast to high chemical stability (t1/2 55.4 h at 36.4 deg C), with porcine liver carboxyesterase the title compound 1 spontaneously decomposes first to the monoester 2 then to methylphosphonate, both reactions proceeding via the 4-hydroxybenzyl intermediates 3 and 4.
- Freeman, Sally,Irwin, William J.,Mitchell, Antony G.,Nicholls, Dave,Thomson, William
-
p. 875 - 877
(2007/10/02)
-
- N-METHYL-2-DIMETHYLAMINOACETOHYDROXAMIC ACID AS A NEW REAGENT FOR THE SELECTICE CLEVEAGE OF ACTIVE ESTERS UNDER NEUTRAL CONDITIONS
-
A new reagent, N-methyl-2-dimethylaminoacetohydroxamic acid 3 was developed for the selective cleavage of active esters under neutral conditions.The kinetic studies and the applications of 3 are described.
- Ono, Mitsunori,Itoh, Isamu
-
p. 207 - 210
(2007/10/02)
-
- PROTECTION DES PHENOLS PAR LE GROUPEMENT AZIDOMETHYLENE APPLICATION A LA SYNTHESE DE PHENOLS INSTABLES
-
Phenols are protected by the azidomethylene group in basic, nucleophilic, oxidative, weakly reductive and weakly acidic media.This group is obtained by the reaction of sodium azide with aryloxymethyl chlorides.Its utility lies in the ease with which it can be removed under very mild conditions which allows the synthesis of very unstable phenolic compounds.
- Loubinoux, Bernard,Tabbache, Samir,Gerardin, Philippe,Miazimbakana, Joseph
-
p. 6055 - 6064
(2007/10/02)
-
- SELECTIVE DESILYLATION OF PHENOLIC AND ALCOHOLIC TRIMETHYLSILYL ETHERS
-
A quaternary ammonium resin ( phenolated HO form ) and a carboxylate resin ( H form ) will selectively remove phenolic and alcoholic trimethylsilyl group, respectively, under controlled conditions.
- Kawazoe, Yutaka,Nomura, Makoto,Kondo, Yumiko,Kohda, Kohfuku
-
p. 4307 - 4310
(2007/10/02)
-
- UTILISATION DE LA GUANIDINE COMME AGENT DESACETYLANT SELECTIF: UNE METHODE DE DESACETYLATION INSTANTANEE APPLICABLE AUX SUCRES
-
Guanidine efficiently and instantly deprotects a series of acetylated carbohydrates and phenols at room temperature.Phenolic acetates can be cleaved in the presence of benzylic acetates, while acetamides, benzoates and pivaloates remain stable.
- Kunesch, Nicole,Miet, Christine,Poisson, Jacques
-
p. 3569 - 3572
(2007/10/02)
-