cas 540-88-5, tert-Butyl acetate | Articles data

Articles about 540-88-5Total 153 be found

Article title
Article abstract
Author
Journal number and time
Download

Esterification of tert-butanol and acetic acid by silicotungestic acid catalyst supported on bentonite
A series of solid acid catalysts were synthesized by incipient wetness impregnation method by varying the wt % of silicotungstic acid on bentonite. Silicotungestic acid supported on bentonite was used to catalytic synthesis of tert-butyl acetate with acetic acid and tert-butyl alcohol. The main reaction parameters such as silicotungstic acid loading on bentonite, the amount of catalyst, molar ratio of reactants, reaction temperature and reaction time have been investigated. The optimum conditions were determined as follows: silicotungstic acid loading on bentonite 25 wt %, catalyst 0.7 g, mole ratio of tert-butanol to acetic acid 1:1.1, reaction temperature 110 °C and reaction time 2 h. The esterification yield of tert-butyl acetate was about 87.2 %. The catalyst could be used repeatedly for many times without distinct loss in activity.
Jin, Jian-Zhong,Sun, Na-Bo
p. 4441 - 4443
(2013)
Read Online

UNE NOUVELLE CLASSE D'INHIBITEURS IRREVERSIBLES: LES SULFINAMOYLESTERS PRECURSEURS DE SULFINES.
Tert-butyl N-aryl sulfinamoyl acetates are hydrolyzed in aqueous basic media following a bimolecular elimination process, via anintermediate sulfine species.The use of sulfinamoyl compounds as irreversible inactivators for zinc-metalloenzymes is emphasized.
Baltas, Michel,Cazaux, Louis,Gorrichon-Guigon, Liliane,Maroni, Pierre,Tisnes, Pierre
p. 4447 - 4450
(1985)
Read Online

Dehydrogenative ester synthesis from enol ethers and water with a ruthenium complex catalyzing two reactions in synergy
We report the dehydrogenative synthesis of esters from enol ethers using water as the formal oxidant, catalyzed by a newly developed ruthenium acridine-based PNP(Ph)-type complex. Mechanistic experiments and density functional theory (DFT) studies suggest that an inner-sphere stepwise coupled reaction pathway is operational instead of a more intuitive outer-sphere tandem hydration-dehydrogenation pathway.
Ben-David, Yehoshoa,Diskin-Posner, Yael,Kar, Sayan,Luo, Jie,Milstein, David,Rauch, Michael
supporting information
p. 1481 - 1487
(2022/03/07)

Molybdenum-modified mesoporous SiO2as an efficient Lewis acid catalyst for the acetylation of alcohols
A suitable, expeditious and well-organized approach for the acetylation of alcohols with acetic anhydride in the presence of 5%MoO3-SiO2 as an optimum environmentally benign heterogeneous catalyst was developed. The high surface area obtained for 5%MoO3-SiO2, 101 m2 g-1 compared to other catalysts, 22, 23, and 44 m2 g-1 for 5%WO3-ZrO2, 5%WO3-SiO2, and 5%MoO3-ZrO2, respectively, appears to be the driving force for better catalytic activity. Amongst the two dopants used, molybdenum oxide is the better dopant compared to its tungsten oxide counterpart. High yields of up to 86% were obtained with MoO3 doping while WO3 containing catalysts did not show any activity. Other reaction parameters such as reactor stirring speed, and solvent variation were studied and revealed that the optimum stirring speed is 400 rpm and cyclohexane is the best solvent. Thus, the utilization of affordable and nontoxic materials, short reaction times, reusability, and producibility of excellent yields of the desired products are the advantages of this procedure.
Hlatshwayo, Xolani S.,Ndolomingo, Matumuene Joe,Bingwa, Ndzondelelo,Meijboom, Reinout
p. 16468 - 16477
(2021/05/19)

Green, efficient and economical coal fly ash based phosphomolybdic acid catalysts: preparation, characterization and application
Abstract: Cost-effective, efficient and green solid acid catalysts have been synthesized by incipient wetness impregnation of various weight fractions of phosphomolybdic acid (5, 10, 15 and 25 wt. %) on mechanically and thermally activated coal fly ash. N2 adsorption–desorption, XRD, FT-IR, SEM, SEM–EDX, TEM, TGA, UV–Vis DRS, solid state 31P MAS NMR were used for characterization of as synthesized catalysts. Catalytic active sites were developed on inert surface of coal fly ash by using various activation techniques whose performance was assessed over a series of acylation of various aliphatic alcohols. For rapid and higher catalytic activity, reactions were conducted in microwave heating mode. Impregnation of phosphomolybdic acid generates Lewis acidic sites on coal fly ash surface as inferred by pyridine adsorbed FT-IR studies which were then utilized in acylation reactions. Various reaction parameters like weight fraction of catalysts, molar ratio of reactants, time, temperature, etc. were optimized for attaining highest conversion %. The catalyst with 15 wt. % of phosphomolybdic acid was found to be more efficient and could be recycled up to five reaction cycles with analogous conversion %. Negligible leaching of catalyst was confirmed by hot filtration test. This work suggests an alternative approach for valorisation of industrial solid waste, coal fly ash in development of innovative, economical solid catalysts. Graphic abstract: [Figure not available: see fulltext.].
Malpani, Sakshi Kabra,Goyal, Deepti,Katara, Stuti,Rani, Ashu
p. 3017 - 3034
(2021/02/26)

Genome mining reveals new bacterial type I Baeyer-Villiger monooxygenases with (bio)synthetic potential
Baeyer-Villiger monooxygenases (BVMOs) are oxidorreductases that catalyze the oxidation of ketones in a very selective manner. By genome mining we detected seven putative type I BVMOs in Bradyrhizobium diazoefficiens USDA 110. As we established the phylogenetic relationships among them and with other type I BVMOs, we found out that they belong to different clades of the phylogenetic tree. Thus, we decided to clone and heterologously express five of them. Three of them, each one from a divergent phylogenetic group, were obtained as soluble proteins, allowing us to proceed with their biocatalytic assessment and enzymatic characterization. As to substrate scope and selectivity, we observed a complementary behavior among the three BVMOs. BVMO2 was the more versatile biocatalyst in whole-cell systems while BVMO4 and BVMO5 showed a narrow substrate profile with preference for linear ketones and particular regioselectivity for (±)-cis-bicyclo[3.2.0]hept-2-en-6-one.
Bianchi, Dario A.,Carabajal, María Ayelén,Ceccoli, Romina D.,Rial, Daniela V.
(2020/03/19)

Scalable green approach toward fragrant acetates
The advantageous properties of ethylene glycol diacetate (EGDA) qualify it as a useful substitute for glycerol triacetate (GTA) for various green applications. We scrutinised the lipase-mediated acetylation of structurally diverse alcohols in neat EGDA furnishing the range of naturally occurring fragrant acetates. We found that such enzymatic system exhibits high reactivity and selectivity towards activated (homo) allylic and non-activated primary/secondary alcohols. This feature was utilised in the scalable multigram synthesis of fragrant (Z)-hex-3-en-1-yl acetate in 70percent yield. In addition, the Lipozyme 435/EGDA system was also found to be applicable for the chemo-selective acetylation of (hydroxyalkyl) phenols as well as for the kinetic resolution of chiral secondary alcohols. Lastly, its discrimination power was demonstrated in competitive experiments of equimolar mixtures of two isomeric alcohols. This enabled the practical synthesis of 1-pentyl acetate isolated as a single product in 68percent yield from the equimolar mixture of 1-pentanol and 3-pentanol.
Puchl'Ová, Eva,Szolcsányi, Peter
(2020/08/07)

Cyanation of Anilines to Aryl Nitriles Using tert-Butyl Isocyanide: A Simple and Copper-free Procedure
In this manuscript, a simple and copper-free procedure for the synthesis of aryl nitrile derivatives from anilines is described. Under the improved protocol, the anilines were reacted with tert-butyl isocyanide under a mild reaction condition without the use of solvents and copper catalyst to synthesize benzonitriles. This copper-free Sandmeyer-type reaction could tolerate a range of anilines bearing different functional groups and also can be conducted even without the exclusion of air. In addition, this method has afforded the aryl nitriles in moderate to good yields (52–81%). The obtained results in this study reveal that the tert-butyl isocyanide as a potential cyanide source for the cyanation reaction.
Chia, Poh Wai,Yong, Fu Siong Julius,Mohamad, Habsah,Kan, Su-Yin
supporting information
p. 939 - 942
(2019/08/21)

Magnetically recoverable AlFe/Te nanocomposite as a new catalyst for the facile esterification reaction under neat conditions
In this work, a new Fe3O4/AlFe/Te nanocomposite was synthesized by a one-step sol–gel method. The Fe3O4 magnetic nanoparticles (MNPs) were prepared and then mixed with aluminum telluride (Al2Te3) in an alkali medium to produce the desired catalyst. After characterization of the Fe3O4/AlFe/Te nanocomposite by SEM, TEM, EDS, XRD, and ICP analyses, it was used in the esterification reaction. This heterogeneous catalyst showed high catalytic activity in the esterification of commercially available carboxylic acids with various alcohols to produce the desired esters at high conversions under neat conditions. The Fe3O4/AlFe/Te nanocomposites were separated from the reaction mixture via an external magnet and re-used 8 times without significant loss of catalytic activity.
Alavi, Seyed Jamal,Sadeghian, Hamid,Seyedi, Seyed Mohammad,Eshghi, Hossein,Salimi, Alireza
(2017/11/23)

N-Hydroxyphthalimide (NHPI) Promoted Aerobic Baeyer-Villiger Oxidation in the Presence of Aldehydes
Metal-free aerobic Baeyer-Villiger (BV) oxidation of ketones to lactones or esters in the presence of aldehydes promoted by N-hydroxyphthalimide (NHPI) has been developed. The reaction proceeded under mild conditions with excellent selectivity and high yields. Compared with the methods that use metal complexes as catalysts, this strategy not only showed good environmental advantages, but also increased aldehyde efficiency up to 84 %. Control experiments indicated that NHPI accelerated the oxidation of aldehydes to peroxy acids but did not improve the BV oxidation while peroxy acids were already generated. Peroxy acids generated from aldehydes in situ were the key intermediates, and the phthalimide-N-oxyl radical (PINO) contributed to high aldehyde efficiency by stabilizing the radical species, which are necessary for the chain propagation reactions. This study may offer some useful strategies for new transition metal-free catalytic aerobic oxidation reactions in which aldehydes act as sacrificial agents.
Wang, Lingyao,Wang, Yongtao,Du, Renfeng,Dao, Rina,Yuan, Haoran,Liang, Cheng,Yao, Jia,Li, Haoran
p. 4961 - 4966
(2018/10/02)

Reusable and efficient polyvinylpolypyrrolidone-supported triflic acid catalyst for acylation of alcohols, phenols, amines, and thiols under solvent-free conditions
Abstract: A triflic acid-functionalized polyvinylpolypyrrolidone was prepared and fully characterized by FT-IR, TGA, and SEM. This super acidic solid catalyst shows high catalytic activity for selective acylation of alcohols, phenols, amines, and thiols with anhydrides under solvent-free conditions at room temperature. In addition, this method features an easy to handle solid super acid catalyst and an operationally simple procedure, affording the desired acylated products in excellent yields. Graphical abstract: [Figure not available: see fulltext.].
Tajbakhsh, Mahgol,Tajbakhsh, Mahmoud,Khaksar, Samad,Gazvini, Helia Janatian,Heidary, Marzieh
p. 1117 - 1122
(2017/05/10)

Exploring the catalytic activity of Lewis-acidic uranyl complexes in the nucleophilic acyl substitution of acid anhydrides
The catalytic activities of several uranyl complexes, such as N,N′-disalicylidene-o-phenelyenediaminato(ethanol)dioxouranium(vi) (UO2(salophen)EtOH), bis(dibenzoylmethanato)(ethanol)dioxouranium(vi) (UO2(dbm)2EtOH), pentakis(N,N-dimethylformamide)dioxouranium(vi) ([UO2(DMF)5]2+), and tetrakis(triphenylphosphine oxide)dioxouranium(vi) ([UO2(OPPh3)4]2+), were examined in the nucleophilic acyl substitution of acid anhydrides. Among them, [UO2(OPPh3)4]2+ was the most efficient to give ethyl acetate and acetic acid from acetic anhydride (Ac2O) and ethanol, and was resistant towards decomposition during the catalytic reaction. Several nucleophiles were also subjected to the catalytic acylation reaction using acetic and pivalic anhydride. Kinetic and spectroscopic studies suggested that [UO2(OPPh3)4]2+ interacts with Ac2O to form [UO2(Ac2O)(OPPh3)3]2+. Interaction of this actual catalyst with additional Ac2O determines the rate of the overall nucleophilic acyl substitution reaction.
Takao, Koichiro,Akashi, Shin
p. 12201 - 12207
(2017/03/08)

METHOD FOR PRODUCING FLUORINATED HYDROCARBON
PROBLEM TO BE SOLVED: To provide a method for industrially advantageously producing a fluorinated hydrocarbon. SOLUTION: The method for producing a fluorinated hydrocarbon represented by formula (3) comprises bringing a secondary or tertiary ether compound represented by formula (1) into contact with an acid fluoride represented by formula (2) in the presence of a compound having an N-X bond (X is a halogen atom selected from a chlorine atom, a bromine atom, and an iodine atom) in a halogenated hydrocarbon-based solvent. (R1 and R2 are each independently a C1-C3 alkyl group; R3 is H, a methyl group, or an ethyl group; R4 and R5 are each a methyl group or an ethyl group; and R1 and R2 may be bonded together to form a ring structure.) SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
-
Paragraph 0064; 0068; 0072

(2018/03/09)

Template-free sol–gel synthesis of high surface area mesoporous silica based catalysts for esterification of di-carboxylic acids
High surface area mesoporous silica based catalysts have been prepared by a simple hydrolysis/sol–gel process without using any organic template and hydrothermal treatment. A controlled hydrolysis of ethyl silicate-40, an industrial bulk chemical, as a silica precursor, resulted in the formation of very high surface area (719?m2/g) mesoporous (pore size 67?? and pore volume 1.19?cc/g) silica. The formation of mesoporous silica has been correlated with the polymeric nature of the ethyl silicate-40 silica precursor which on hydrolysis and further condensation forms long chain silica species which hinders the formation of a close condensed structure thus creating larger pores resulting in the formation of high surface mesoporous silica. Ethyl silicate-40 was used further for preparing a solid acid catalyst by supporting molybdenum oxide nanoparticles on mesoporous silica by a simple hydrolysis sol–gel synthesis procedure. The catalysts showed very high acidity as determined by NH3-TPD with the presence of Lewis as well as Br?nsted acidity. These catalysts showed very high catalytic activity for esterification; a typical acid catalyzed organic transformation of various mono- and di-carboxylic acids with a range of alcohols. The in situ formed silicomolybdic acid heteropoly-anion species during the catalytic reactions were found to be catalytically active species for these reactions. Ethyl silicate-40, an industrial bulk silica precursor, has shown a good potential for its use as a silica precursor for the preparation of mesoporous silica based heterogeneous catalysts on a larger scale at a lower cost.
More, Pavan M.,Umbarkar, Shubhangi B.,Dongare, Mohan K.
p. 1247 - 1253
(2016/10/13)

Double-modified mesoporous molecular sieve catalytic SBA method for preparing carboxylic acid T-butyl ester
The invention discloses a method for preparing tert-butyl carboxylate by using a dual-modified SBA mesoporous molecular sieve catalyst. According to the method, carboxylic acid and isobutylene are subjected to addition esterification by using a dual-modified SBA mesoporous molecular sieve as a catalyst to synthesize the tert-butyl carboxylate. The molecular sieve catalyst is a metal-doped sulfonate-grafted dual-modified SBA mesoporous molecular sieve catalyst prepared by a one-step cocondensation process. When the dual-modified SBA mesoporous molecular sieve catalyst is used in the addition esterification reaction process of synthesizing tert-butyl carboxylic acid from carboxylic acid and isobutylene, no polar solvent (such as tert-butyl alcohol, methyl tert-butyl ether or the like) is needed as an isobutylene polymerization inhibitor, and the quantity of the carboxylic acid is not excessive, thereby reducing the energy consumption for separating the reaction product. The catalyst has the advantages of high conversion rate, high selectivity, non-homogeneous phase, no corrosiveness, adjustable acid quantity and acid center and the like, and is recyclable.
-
Paragraph 0048; 0049

(2016/11/21)

Highly efficient and recyclable acetylation of phenols and alcohols by nickel zirconium phosphate under solvent-free conditions
Nickel zirconium phosphate nanoparticles have been used as an efficient catalyst for the acetylation of a wide range of alcohols and phenols with acetic anhydride in good to excellent yields under solvent-free conditions. The steric and electronic properties of the different substrates had a significant influence on the reaction conditions required to achieve the acetylation. The catalyst used in the current study was characterized by inductively coupled plasma optical emission spectroscopy, X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, and transmission electron microscopy. This nanocatalyst could also be recovered and reused at least six times without any discernible decrease in its catalytic activity.
Hajipour, Abdol Reza,Karimi, Hirbod,Kohi, Afshin
p. 55 - 64
(2016/01/09)

Method for preparing tert-butyl acetate from acetic acid and iso-butane
The invention provides a method for preparing tert-butyl acetate from acetic acid and iso-butane. The method includes the steps that acetic acid and iso-butane are reacted in the presence of a catalyst and an oxidizing agent, and tert-butyl acetate is produced. The method for preparing tert-butyl acetate from acetic acid and iso-butane overcomes the defects of the prior art, raw materials are cheap and easy to get, energy consumption is low, the selectivity of tert-butyl acetate is high, and economic benefits are more remarkable.
-
Paragraph 0052; 0053

(2016/10/08)

A sulfonated Schiff base dimethyltin(iv) coordination polymer: Synthesis, characterization and application as a catalyst for ultrasound- or microwave-assisted Baeyer-Villiger oxidation under solvent-free conditions
The synthesis and crystal structure of the new dimethyltin(iv) compound [SnMe2(HL)(CH3OH)]n·(0.5nCH3OH) (1) derived from the Schiff base 2-[(2,3-dihydroxyphenyl)methylideneamino]benzenesulfonic acid (H3L) are described. Despite having six potentially donating centres (one imine nitrogen, two phenoxo and three sulfonate oxygen atoms), the monoprotonated dianionic ligand (HL2-) behaves as an O,O,O-tridentate chelator. Single crystal X-ray diffraction revealed that 1 is a 1D coordination polymer with every tin(iv) ion bound to two methyl groups, a methanol molecule, two Ophenoxo and one μ-Osulfonate atom from HL2-. The coordination polymer 1 was applied as a heterogeneous catalyst for the Baeyer-Villiger oxidation of ketones to esters or lactones, using aqueous hydrogen peroxide as oxidant, under ultrasound (US) or microwave (MW) irradiation and solvent- and additive-free conditions. Overall conversions up to 76/82, 98/93, 93/89, 91/94, 83/90, 68/62 and 81/87% under US/MW irradiations were obtained with 3,3-dimethyl-2-butanone, cyclopentanone, 2-methylcyclopentanone, cyclohexanone, 3-methylcyclohexanone, benzophenone and acetophenone, respectively. The catalyst can be recycled up to five cycles without losing appreciable activity.
Martins, Luísa M.D.R.S.,Hazra, Susanta,Guedes Da Silva, M. Fátima C.,Pombeiro, Armando J. L.
p. 78225 - 78233
(2018/06/22)

Copper Catalyzed sp3 C-H Etherification with Acyl Protected Phenols
A variety of acyl protected phenols AcOAr participate in sp3 C-H etherification of substrates R-H to give alkyl aryl ethers R-OAr employing tBuOOtBu as oxidant with copper(I) β-diketiminato catalysts [CuI]. Although 1°, 2°, and 3° C-H bonds may be functionalized, selectivity studies reveal a preference for the construction of hindered, 3° C-OAr bonds. Mechanistic studies indicate that β-diketiminato copper(II) phenolates [CuII]-OAr play a key role in this C-O bond forming reaction, formed via transesterification of AcOAr with [CuII]-OtBu intermediates generated upon reaction of [CuI] with tBuOOtBu.
Salvador, Tolani K.,Arnett, Charles H.,Kundu, Subrata,Sapiezynski, Nicholas G.,Bertke, Jeffery A.,Raghibi Boroujeni, Mahdi,Warren, Timothy H.
supporting information
p. 16580 - 16583
(2017/01/10)

A catalytic conversion method for preparing pyruvate ester of lactic acid (by machine translation)
A method for preparing pyruvate through catalytic conversion of lactic acid is provided; according to the method, with oxygen or air as an oxidant, alcohol as a solvent, and molybdovanadophosphoric heteropoly acid and/or tungstovanadophosphoric heteropoly acid as a catalyst, and by coupling of a catalytic oxidation reaction and an esterification reaction, lactic acid is converted into pyruvate by one step. The method directly adopts oxygen or air as the oxidant and is green and safe; the used raw material lactic acid is obtained directly from conversion of biomass resources, moreover, the reaction conditions are mild, and the method has important application prospects.
-
Paragraph 0023

(2016/10/10)

Acetylation of alcohols and phenols under solvent-free conditions using iron zirconium phosphate
Iron zirconium phosphate (ZPFe) nanoparticles were found to function as an efficient catalyst for the acetylation of a wide range of alcohols and phenols using acetic anhydride, generating good to excellent yields under solvent-free conditions. The steric and electronic properties of various substrates had a significant influence on the reaction conditions required to achieve the acetylation. The catalyst used in the current study was characterized by inductively coupled plasma-optical emission spectrometry, X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, and transmission electron microscopy. These analyses revealed that the interlayer distance in the catalyst increased from 7.5 to 9.3 ? when Fe3+ was intercalated between the layers, whereas the crystallinity of the material was reduced. This nanocatalyst could also be recovered and reused at least six times without any discernible decrease in its catalytic activity. This new method for the acetylation of alcohols and phenols has several important advantages, including mild and environmentally friendly reaction conditions, as well as good to excellent yields and a facile work-up.
Hajipour, Abdol R.,Karimi, Hirbod,Masti, Amir
p. 595 - 602
(2015/09/28)

Acid-catalyzed oxidation of levulinate derivatives to succinates under mild conditions
Levulinate derivatives are an attractive platform for the production of renewable chemicals. Here we report on the oxidation of methyl levulinate into dimethyl succinate with peroxides under mild conditions using Br?nsted and Lewis acid catalysts. Selectivities to succinate and acetate derivatives of approximately 60 and 40 %, respectively, were obtained with strong Br?nsted acids in methanol. Although the molecular structure (i.e., carbon-chain length and branching around the C=O group) and the oxidant type affect the product distribution, solvent choice has the strongest impact on changing the location of oxygen insertion into the carbon backbone. Specifically, switching the solvent from methanol to heptane resulted in a decrease in the succinate/acetate ratio from 1.6 to 0.3. In contrast to Br?nsted acids, we demonstrate that the nature of the metal cation is responsible for changing the reaction selectivity of water-tolerant Lewis acidic triflate salts.
Wang, Yuran,Vogelgsang, Ferdinand,Román-Leshkov, Yuriy
p. 916 - 920
(2015/03/18)

Baeyer-Villiger oxidation under Payne epoxidation conditions
A novel method for the Baeyer-Villiger oxidation of ketones has been developed and optimized. The transformation involves a transition metal-free activation of hydrogen peroxide under Payne epoxidation conditions. Reaction of a ketone with hydrogen peroxide in the presence of a nitrile under mildly basic reaction conditions leads to the corresponding ester. The transformation has been successfully applied to a range of ketones in moderate to excellent yields (30-91%) and good to excellent regioselectivities (7:1 to 20:1).
Bradley, Tyne D.,Dragan, Andrei,Tomkinson, Nicholas C.O.
p. 8155 - 8161
(2015/12/31)

Bacteriogenic iron oxide as an effective catalyst for Baeyer-Villiger oxidation with molecular oxygen and benzaldehyde
Iron oxide produced by iron-oxidizing bacteria, Leptothrix ochracea, (L-BIOX) obtained from a freshwater purification plant, Joyo City in Kyoto, Japan catalyzed Baeyer-Villiger oxidation with molecular oxygen in the presence of benzaldehyde at 25 °C more efficiently than usual iron compounds. L-BIOX can promote the reactions of various substrates to give the desired products in sufficient yields and was found to be reusable. Scanning transmission electron microscopy and 57Fe M?ssbauer spectroscopy revealed that no change of the surface structure of L-BIOX was observed even after four times of the recycling test and the oxidation state of iron in L-BIOX is trivalent before and after the oxidation of cyclohexanone. An investigation with analogous amorphous iron oxides which contain silicon revealed that the catalytic activity of L-BIOX might stem from a synergetic effect of iron and silicon in the structure.
Mandai, Kyoko,Hanata, Minae,Mitsudo, Koichi,Mandai, Hiroki,Suga, Seiji,Hashimoto, Hideki,Takada, Jun
p. 9403 - 9407
(2015/11/18)

CAL-B-Catalyzed Enantioselective Deacetylation of Some Benzylic Acetate Derivatives Via Alcoholysis in Non-aqueous Media
Enantioselective deacetylation of a set of benzylic acetates via alcoholysis catalyzed by Lipase B from Candida antarctica (CAL-B), under mild conditions is described. A systematic study allows to determine the appropriate combination nucleophile/organic solvent and also to explain the influence of these parameters on the enzymatic catalytic reaction. In all cases, (R)-alcohols are obtained with high ee (up to >99 %) at conversion 36 % 500. The enzymatic reactivity is influenced by the hydrophobicity of solvent and the structure/nature of the nucleophile. Furthermore, CAL-B allows enantio-complementary between transesterifications in non-aqueous media: alcoholysis and acetylation.
Zadi, Amna,Merabet-Khelassi, Mounia,Aribi-Zouioueche, Louisa
p. 1054 - 1061
(2015/02/05)

A simple acetylation of alcohols using ZnO nanopowder synthesized by microwave irradiation
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
p. 631 - 634
(2014/06/23)

Facile synthesis of mesoporous sulfated Ce/TiO2 nanofiber solid superacid with nanocrystalline frameworks by using collagen fibers as a biotemplate and its application in esterification
Collagen fibers, one of the most abundant biomass in the natural world, were used as the biomass template to synthesize cerium-doped mesoporous TiO 2 nanofiber (SO42--Cex/TiO 2) solid acid catalysts. The physiochemical properties of the as-prepared catalysts were well characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), N2 adsorption-desorption isotherms, X-ray photoelectron spectroscopy (XPS). The fibrous morphology of native collagen fibers were found to be well preserved in SO42--Ce x/TiO2, and the acid strength and textural property of the SO42--Cex/TiO2 were adjustable by changing the doping amount of Ce and the curing temperature. The catalytic properties of as-prepared catalysts were evaluated in the esterification reactions. It was found that the SO42--Ce x/TiO2 exhibited high activity under mild reaction conditions. When reacted at 90 °C for 45 min with a catalyst amount of 2 wt%, the conversion yields of ethyl acetate, butyl acetate, hexyl acetate and ethyl caproate were 99.9%, 97.06%, 94.29% and 86.75%, respectively. Additionally, the SO42--Cex/TiO2 solid acid catalyst could be reused at least 6 times without significant loss of activity, exhibiting much better reusability as compared with the SO 42--TiO2* catalyst prepared by conventional approach.
Xiao, Gao,Zhou, Jianfei,Huang, Xin,Liao, Xuepin,Shi, Bi
p. 4010 - 4019
(2014/01/06)

Acetylation of alcohols and phenols by zinc zirconium phosphate as an efficient heterogeneous catalyst under solvent-free conditions
An efficient method for the acetylation of a wide range of alcohols as well as phenols with acetic anhydride in good to excellent yields under solvent-free conditions, using zinc zirconium phosphate as the catalyst was investigated. The catalyst was characterized by XRD, inductivity coupled plasma-optical emission spectroscopy, and scanning electron microscope. Products are easily isolated and the protocol is mild and green, compared to the existing methods. Graphical abstract: [Figure not available: see fulltext.]
Hajipour, Abdol Reza,Karimi, Hirbod,Karimzadeh, Morteza
p. 1461 - 1472
(2014/09/30)

Acetylation of alcohols and phenols under solvent-free conditions using copper zirconium phosphate
Copper zirconium phosphate nanoparticles have been used as an efficient catalyst for the acetylation of a wide range of alcohols and phenols with acetic anhydride in good to excellent yields under solvent-free conditions. The steric and electronic properties of the different substrates had a significant influence on the reaction conditions required to achieve the acetylation. The catalyst used in the current study was characterized by inductively-coupled plasma optical emission spectroscopy, energy dispersive spectroscopy, X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, and transmission electron microscopy. These analyses revealed that the interlayer distance in the catalyst increased from 7.5 to 8.0 ? when Cu2+ was intercalated between the layers, whereas the crystallinity of the material was reduced. This nanocatalyst could also be recovered and reused at least six times without any discernible decrease in its catalytic activity. This new method for the acetylation of alcohols and phenols has several key advantages, including mild and environmentally friendly reaction conditions, as well as good to excellent yields and a facile work-up.
Hajipour, Abdol R.,Karimi, Hirbod
p. 1982 - 1989
(2015/09/28)

Preparation and characterization of multi-walled carbon nanotubes (MWCNTs), functionalized with phosphonic acid (MWCNTs-C-PO3H2) and its application as a novel, efficient, heterogeneous, highly selective and reusable catalyst for acetylation of alcohols, phenols, aromatic amines, and thiols
A novel, efficient, heterogeneous, and reusable multi-walled carbon nanotubes (MWCNTs), functionalized with phosphonic acid (MWCNTs-C-PO 3H2) has been synthesized. The synthesized CNTs were characterized using some electron microscopic techniques such as scanning electron microscopy (SEM), atomic force microscopy (AFM), Energy dispersive X-ray spectroscopy (EDAX), and also some thermal and spectroscopic methods such as thermogravimetry (TG). The nitrogen adsorption behavior of the MWCNTs-C-PO3H2 catalyst was evaluated using the TG instrumentation system at 25°C. The catalyst was applied successfully for highly efficient and selective acetylation of alcohols, phenols, thiols and aromatic amines with acetic anhydride at room temperature under solvent-free conditions. The reusability of the catalyst was checked and the recovered catalyst was reused for five runs without significant loss in activity.
Dehghani, Farzaneh,Sardarian, Ali Reza,Doroodmand, Mohammad Mehdi
p. 673 - 684
(2014/05/20)

Lewis basic ionic liquid as an efficient and facile catalyst for acetylation of alcohols, phenols, and amines under solvent-free conditions
The Lewis basic ionic liquid 1,8-diazabicyclo[5.4.0]undec-7-en-8-ium acetate was employed for the acetylation of various phenols, alcohols, and amines in good-to-excellent yields at 50 C under solvent-free conditions in a short time. Compared with existing methods based on conventional catalysts and toxic solvents, the reported method is simple, mild and environmentally viable. Furthermore, the ionic liquid was conveniently separated from the products and easily recycled to catalyze other acetylation reactions with excellent yields. .
Ji, Li,Qian, Chao,Chen, Xin-Zhi
p. 369 - 374
(2013/05/21)

Oxorhenium complexes bearing the water-soluble tris(pyrazol-1-yl) methanesulfonate, 1,3,5-triaza-7-phosphaadamantane, or related ligands, as catalysts for Baeyer-Villiger oxidation of ketones
New rhenium(VII or III) complexes [ReO3(PTA)2] [ReO4] (1) (PTA = 1,3,5-triaza-7-phosphaadamantane), [ReO 3(mPTA)][ReO4]I (2) (mPTA = N-methyl-1,3,5-triaza-7- phosphaadamantane cation), [ReO3(HMT)2][ReO4] (3) (HMT = hexamethylenetetramine), [ReO3(η2-Tpm)(PTA) ][ReO4] (4) [Tpm = hydrotris(pyrazol-1-yl)methane, HC(pz) 3, pz = pyrazolyl], [ReO3(Hpz)(HMT)][ReO4] (5) (Hpz = pyrazole), [ReO(Tpms)(HMT)] (6) [Tpms = tris(pyrazol-1-yl) methanesulfonate, O3SC(pz)3-] and [ReCl 2{N2C(O)Ph}(PTA)3] (7) have been prepared from the Re(VII) oxide Re2O7 (1-6) or, in the case of 7, by ligand exchange from the benzoyldiazenido complex [ReCl2{N 2C(O)Ph}(Hpz)(PPh3)2], and characterized by IR and NMR spectroscopies, elemental analysis and electrochemical properties. Theoretical calculations at the density functional theory (DFT) level of theory indicated that the coordination of PTA to both Re(III) and Re(VII) centers by the P atom is preferable compared to the coordination by the N atom. This is interpreted in terms of the Re-PTA bond energy and hard-soft acid-base theory. The oxo-rhenium complexes 1-6 act as selective catalysts for the Baeyer-Villiger oxidation of cyclic and linear ketones (e.g., 2-methylcyclohexanone, 2-methylcyclopentanone, cyclohexanone, cyclopentanone, cyclobutanone, and 3,3-dimethyl-2-butanone or pinacolone) to the corresponding lactones or esters, in the presence of aqueous H2O2. The effects of a variety of factors are studied toward the optimization of the process.
Martins, Luisa M. D. R. S.,Alegria, Elisabete C. B. A.,Smolenski, Piotr,Kuznetsov, Maxim L.,Pombeiro, Armando J. L.
p. 4534 - 4546
(2013/06/04)

Pentafluorophenylammonium triflate as a mild and new organocatalyst for acylation of alcohols, phenols, and amines under solvent-free condition
A simple, inexpensive, environmentally friendly and efficient route for the acylation of a number of alcohols, phenols and amines using pentafluorophenylammonium triflate (PFPAT) as a catalyst is described. PFPAT organocatalyst is air-stable, cost-effective, easy to handle, and easily removed from the reaction mixtures.
Khaksar, Samad,Zakeri, Hasan
p. 576 - 579,4
(2020/08/31)

Novel double-SO3h functionalized ionic liquid for acetylation
Novel double-SO3H functionalized ionic liquid (DFIL) was synthesized and its catalytic activities for acetylation studied. The result showed that the DFIL possess high acidity and was very efficient for the acetylation of alcohols, amines and phenols with good to excellent yields in short reaction times. Operational simplicity, stability to water and air, small amounts needed, low cost, high yields, high acidity, applicability to large-scale reactions and reusability are the key features of the DFIL, which indicated promising applications of DFIL in green chemical processes. Pleiades Publishing, Ltd., 2012.
Zhu, Lili,Liang, Xuezheng
p. 684 - 688
(2013/02/23)

A mild and clean Baeyer-Villiger oxidation of ketones using sodium peroxydisulfate as oxidant catalyzed by silica-supported aluminum chloride
Sodium peroxydisulfate was used as the oxidant for Baeyer-Villiger oxidation of a variety of cyclic and acyclic ketones at room temperature in the presence of Silica-supported aluminum chloride (silica-AlCl3) as catalyst. The catalyst was prepared by a simple procedure, which exhibited high catalytic activity for the Baeyer- Villiger oxidation of ketones using environmental friendly sodium peroxydisulfate as oxidizing agent. Iranian Chemical Society 2012.
Mahmoodi, Nosrat Ollah,Heirati, Seyedeh Zahra Dalil,Ekhlasi-Kazaj, Kamel
p. 521 - 528
(2013/02/22)

Baeyer-Villiger oxidation of ketones catalysed by rhenium complexes bearing N- or oxo-ligands
Rhenium (I, III-V or VII) complexes bearing N-donor or oxo-ligands catalyse the Baeyer-Villiger oxidation of cyclic and linear ketones (e.g. 2-methylcyclohexanone, 2-methylcyclopentanone, cyclohexanone, cyclopentanone, cyclobutanone and 3,3-dimethyl-2-butanone) into the corresponding lactones or esters, in the presence of aqueous H2O2 (30%). The effects of various reaction parameters are studied allowing to achieve yields up to 54%.
Alegria, Elisabete C.B.A.,Martins, Luísa M.D.R.S.,Kirillova, Marina V.,Pombeiro, Armando J.L.
p. 27 - 32
(2012/10/29)

ACYLATIONS IN MICRO REACTION SYSTEMS
A method for acylating tertiary alcohols and phenolic compounds with carboxylic acids or their anhydrides in micro-reaction systems wherein the acylation is effected in the absence of any catalyst including water at residence times of at most 30 minutes.
-
Page/Page column 7

(2011/08/04)

Silver triflate catalyzed acetylation of alcohols, thiols, phenols, and amines
A variety of alcohols, thiols, phenols, and amines were subjected to acetylation reaction using acetic anhydride in the presence of catalytic quantity of silver triflate. The method described has a wide range of applications, proceeds under mild conditions, does not involve cumbersome workup, and the resulting products are obtained in high yields within a reasonable time. Georg Thieme Verlag Stuttgart · New York.
Das, Rima,Chakraborty, Debashis
experimental part
p. 1621 - 1625
(2011/06/25)

Highly efficient and versatile acetylation of alcohols, phenols and amines catalyzed by methylenediphosphonic acid (MDP) under solvent-free conditions
Methylenediphosphonic Acid (MDP) was found to be a simple, cheap and reusable heterogeneous catalyst for the acetylation of structurally diverse alcohols, phenols and amines with acetic anhydride under solvent-free conditions at room temperature. This method showed preferential selectivity for the acetylation of the amino group in the presence of hydroxyl group. The method is very mild and the yields were in excellent.
Xie, Minhao,Wang, Hongyong,Wu, Jun,He, Yongjun,Liu, Yaling,Zou, Pei
experimental part
p. 884 - 886
(2012/04/23)

P2O5/Al2O3 AS an efficient heterogeneous catalyst for the acetylation of alcohols, phenols, thiols, and amines under solvent-free conditions
A convenient, rapid, and efficient method for the acetylation of alcohols, phenols, thiols, and amines has been developed by using acetic anhydride in the presence of a catalytic amount of P2O5/Al 2O3 under solvent-free conditions at room temperature. This reaction was studied under different conditions, and several solvents were examined for this conversion. However, in terms of reaction time and yield, it was found that the best result was obtained when the reaction was carried out under solvent-free conditions. Racemization of optically active alcohols and epimerization of sugars were not observed. The use of nontoxic and inexpensive materials, simple and clean workup, short reaction times, and good yields of the products are the advantages of this method.
Zarei, Amin,Hajipour, Abdol R.,Khazdooz, Leila
experimental part
p. 1772 - 1785
(2011/06/20)

Iron (III) phosphate as a green and reusable catalyst promoted chemo selective acetylation of alcohols and phenols with acetic anhydride under solvent free conditions at room temperature
Iron (III) phosphate was employed as an efficient catalyst for the chemo selective acetylation of alcohols and phenols under solvent free condition at room temperature and with high yields. Iron (III) phosphate is also a potential green catalyst due to solid intrinsically, reusable and with high catalytic activity.
Behbahani,Farahani,Oskooie
experimental part
p. 633 - 637
(2011/10/08)

Investigation of catalytic activity of high-valent vanadium(IV) tetraphenylporphyrin: A new, highly efficient and reusable catalyst for acetylation of alcohols and phenols with acetic anhydride
In the present work, the catalytic activity of high-valent tetraphenylporphyrinatovanadium(IV) trifluoromethanesulfonate, [V IV(TPP)(OTf)2], in the acetylation of alcohols and phenols with Ac2O is reported. This new V(IV) catalyst was used as an efficient catalyst for not only primary alcohols (benzylic and aliphatic) but also sterically-hindered secondary and tertiary alcohols with acetic anhydride and the corresponding acetates were obtained in 85-99% yield and 0.5-15 min. Acetylation of phenols with acetic anhydride was also performed to afford the desired acetates in 88-99% and 1.5-20 min. This catalyst can be reused several times without loss of its catalytic activity.
Taghavi, S. Abdolmanaf,Moghadam, Majid,Mohammadpoor-Baltork, Iraj,Tangestaninejad, Shahram,Mirkhani, Valiollah,Khosropour, Ahmad Reza
experimental part
p. 159 - 164
(2011/12/16)

Oxidation of β-dicarbonyl compounds with tert-butyl hydroperoxide in the presence of vanadyl acetylacetonate
Oxidation of β-dicarbonyl compounds with tert-butyl hydroperoxide in the presence of vanadyl acetylacetonate (benzene, 20°C) involves the activated methylene group with intermediate formation of trioxo derivatives and is accompanied by decomposition of carbon skeleton. The oxidation products are carbon dioxide, carboxylic acids, and tert-butyl and peroxy esters derived from the latter.
Stepovik,Gulenova,Kalacheva,Potkina, A. Yu.
scheme or table
p. 550 - 558
(2011/06/23)

1-methylimidazolium chlorosulfate ([HMIm]SO3Cl): A novel ionic liquid with dual bronsted-lewis acidity
A novel acidic ionic liquid, 1-methylimidazolium chlorosulfate ([HMIm]SO3Cl), with dual Bransted-Lewis acidity was synthesized. This compound provided better catalytic performance in esterification and dehydration of fructose to 5-hydroxy-methylfurfural (HMF) than acidic ionic liquids with only Bronsted or Lewis acidity.
Bao, Quanxi,Qiao, Kun,Tomida, Daisuke,Yokoyama, Chiaki
scheme or table
p. 728 - 729
(2011/01/05)

Molecular iodine in ionic liquid: A green catalytic system for esterification and transesterification
Esterification of carboxylic acids and transesterification of-ketoesters with alcohols have been developed using a catalytic amount of iodine in polyethylene glycol (PEG) ionic liquid (IL 1000) to afford the corresponding esters in good yields. By simple separation of the ionic-liquid phase containing the iodine, the system of I2/IL 1000 can be reused several times. Copyright
Ren, Yiming,Cai, Chun
scheme or table
p. 1670 - 1676
(2010/08/03)

Synthesis, characterization, and crystal structure of several novel acidic ionic liquids based on the corresponding 1-alkylbenzimidazole with tetrafluoroboric acid
A series of acidic task-specific ionic liquids 1-R2-2-R 1benzimidazolium tetrafluoroborate (R1 = Me, R2 = Me, Et, Pr-n, Bu-n, Pen-n) were prepared by simple acid-base neutralization of the corresponding 1-alkylbenzimidazole and tetrafluoroboric acid. The compounds were characterized by FTIR spectra, elemental analysis, 1HNMR spectra and thermogravimetric analysis. These new ionic liquids are nonvolatile, and have potential use as alternatives to conventional organic solvents due to their solubility and thermal stability. These novel tetrafluoroborate salts show good catalytic activity to esterification of carboxylic acids with alcohols under mild reaction conditions, which could maintain good catalytic performance after recycling at least six times. Furthermore, a crystal of one compound, [H-bmBim]BF4, was prepared, with the crystal structure determined by X-ray diffraction analysis. The molecular structure is formed by weak π-π interactions and intermolecular hydrogen bonds between the benzimidazole rings, yielding a three-dimensional net-like supramolecule.
Chen, Shuan-Hu,Yang, Fen-Rong,Wang, Ming-Tian,Wang, Na-Ni
experimental part
p. 1391 - 1396
(2011/11/05)

The heterogenation of melamine and its catalytic activity
The immobilization of melamine (Mela) onto silica extracted from rice husk ash (RHA) has been done via 3-chloropropyltriethoxysiline (CPTES). The resulting catalyst was designated as RHAPrMela. The melamine loading on the silica was found to be ca. 65.74%. The 29Si MAS NMR showed the presence of T2, T3, Q3 and Q4 silicon centers. The 13C MAS NMR showed that RHAPrMela had three chemical shifts at 14.83, 31.17 and 52.24 ppm, consistent with the three carbon atoms, and two chemical shifts at 161.52 and 169.67 ppm with double spinning side bands, indicating that the three carbon atoms in melamine ring are not equivalent in RHAPrMela. The catalytic potential of RHAPrMela was tested for the esterification of acetic acid with several alcohols. A conversion of 73% was achieved with 100% selectivity for the respective esters. The catalyst was easily regenerated and could be reused many times without loss of catalytic activity.
Adam, Farook,Hello, Kasim Mohammed,Osman, Hasnah
experimental part
p. 115 - 121
(2010/09/04)

Air-stable titanocene bis(perfluorooctanesulfonate) as a new catalyst for acylation of alcohols, phenols, thiols, and amines under solvent-free condition
Air-stable titanocene bis(perfluorooctanesulfonate) [Cp2Ti(OSO2C8F17)2] that shows high Lewis acidity was prepared from Cp2TiCl2 and AgOSO2C8F17. The compound was characterized by different techniques, and examined as a catalyst for acylation reactions. It was found that using equimolar acetic anhydride as acetylating agent and under solvent-free condition, Cp2Ti(OSO2C8F17)2 exhibits high activity and selectivity in the acetylation of various alcohols, phenols, thiols, and amines. Also, good catalytic efficiency is observed in the acylation of 2-phenylethanol across various acylating reagents. The catalyst can be reused without loss of activity in a test of ten cycles. The Cp2Ti(OSO2C8F17)2 catalyst affords a simple, efficient and general method for the acylation of alcohols, phenols, thiols, and amines.
Qiu, Renhua,Zhang, Guoping,Ren, Xiaofang,Xu, Xinhua,Yang, Ronghua,Luo, Shenglian,Yin, Shuangfeng
experimental part
p. 1182 - 1188
(2010/06/13)

Microwave-assisted synthesis of nano-sized cadmium oxide as a new and highly efficient catalyst for solvent free acylation of amines and alcohols
In present studies, a new and efficient method for synthesis of cadmium oxide nanoparticles by using microwave (MW) activation is reported. To ensure the specific efficiency of microwave irradiation versus conventional heating, the synthesis of Cd(OH)2 as precursor of CdO was carried out under similar temperature (80 °C), time and reaction conditions without microwave irradiation. The formation of CdO was characterized by XRD, TEM, FT-IR analysis. Catalytic activity of CdO nanopowder for acylation of alcohols, phenols and amines has been investigated. The results show that the reaction times and yields of desired products were improved by using CdO.
Mazaheritehrani,Asghari,Orimi, R. Lotfi,Pahlavan
experimental part
p. 2554 - 2564
(2010/10/21)

Acetylation of alcohols and phenols with acetic anhydride under solvent-free conditions using an ionic liquid based on morpholine as a recoverable and reusable catalyst
Rapid and efficient acetylation of alcohols and phenols with acetic anhydride is performed in the presence of economical Bronsted acidic ionic liquids that bear a propanesulfonic acid group on a morpholinium cation as catalysts under solvent-free conditions. [MMPPA][HSO4] (N-methylmorpholinium propanesulfonic acid ammonium hydrogensulfate) was proven to be the most active catalyst, and after removal of water, it could be recycled and reused for up to four times without a noticeable decrease in catalytic activity. Springer-Verlag 2010.
Yue, Caibo,Liu, Qingqing,Yi, Tingfeng,Chen, Yun
experimental part
p. 975 - 978
(2011/09/30)

Comparative study of acetylation of alcohols and phenols with different acetylating agents using zinc chloride as catalyst under solvent free conditions at room temperature
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
experimental part
p. 5155 - 5158
(2012/07/28)