- Pd(OAc)2/M(NO3)n (M = Cu(II), Fe(III); n = 2, 3): Kinetic investigations of an alternative Wacker system for the oxidation of natural olefins
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Pd-catalyzed oxidative coupling of camphene by dioxygen afforded mainly a diene, which subsequently underwent oxidation to a ring-expanded β,γ-unsaturated ketone with LiNO3 as reoxidant. However, the instability of LiNO3 results to t
- da Silva, Márcio J.,Teixeira, Róbson Ricardo,Carari, Danielli Marcolan
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Read Online
- Synthesis of Terpineol from Alpha-Pinene Catalyzed by α-Hydroxy Acids
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We report the use of five alpha-hydroxy acids (citric, tartaric, mandelic, lactic and glycolic acids) as catalysts in the synthesis of terpineol from alpha-pinene. The study found that the hydration rate of pinene was slow when only catalyzed by alpha-hydroxyl acids. Ternary composite catalysts, composed of AHAs, phosphoric acid, and acetic acid, had a good catalytic performance. The reaction step was hydrolysis of the intermediate terpinyl acetate, which yielded terpineol. The optimal reaction conditions were as follows: alpha-pinene, acetic acid, water, citric acid, and phosphoric acid, at a mass ratio of 1:2.5:1:(0.1–0.05):0.05, a reaction temperature of 70? C, and a reaction time of 12–15 h. The conversion of alpha-pinene was 96%, the content of alpha-terpineol was 46.9%, and the selectivity of alpha-terpineol was 48.1%. In addition, the catalytic performance of monolayer graphene oxide and its composite catalyst with citric acid was studied, with acetic acid used as an additive.
- Hu, Yi-Ming,Huang, Xiao-Rui,Meng, Zhong-Lei,Qin, Rong-Xiu,Wen, Ru-Si,Zhou, Yong-Hong
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- Preparation of α-terpineol and perillyl alcohol using zeolites beta
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The preparation of α-terpineol by direct hydration of limonene catalyzed by zeolites beta was studied. The same catalyst was used to prepare perillyl alcohol by isomerization of β-pinene oxide in the presence of water. The aim was to optimize the reaction conditions to achieve high conversions of starting material and high selectivity to the desired products. In the case of limonene, it was found that the highest selectivity to α-terpineol was 88% with conversion of 36% under the conditions: 50?wt% of catalyst beta 25, 10% aqueous acetic acid (10?mL) (volume ratio limonene:H2O = 1:4.5), temperature 50?°C, after 24?h. In the case of β-pinene oxide, it was found that the highest selectivity to perillyl alcohol, which was 36% at total conversion, was obtained in the reaction under the following conditions: dimethyl?sulfoxide as solvent (volume ratio β-pinene oxide:DMSO = 1:5), catalyst beta 25 without calcination (15?wt%), demineralized water (molar ratio β-pinene oxide:H2O = 1:8), temperature 70?°C, 3?h. The present study shows that the studied reactions are suitable for the selective preparation of chosen compounds.
- ?erveny, Libor,Vysko?ilová, Eli?ka,Zítová, Kate?ina
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p. 4297 - 4310
(2021/07/26)
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- Heterogeneous zeolite-based catalyst for esterification of α-pinene to α-terpinyl acetate
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The purpose of this study is to determine the most effective type of heterogeneous catalyst such as natural zeolite (ZA), Zr-natural zeolite (Zr/ZA) and zeolite Y (H/ZY) in esterification of α-pinene. α-terpinyl acetate was successfully synthesized from α-pinene and acetic anhydride by their heterogeneous catalysts. The esterification reaction was carried out with reaction time, temperature and zeolite catalysts. The most effective catalysts used in the synthesis of α-terpinyl acetate is catalyst H/ZY with the yield is 52.83% at 40oC for the time 4 h with a selectivity of 61.38%. The results showed that the effective separation of catalyst could contribute to developing a new strategy for the synthesis of α-terpinyl acetate.
- Wijayati, Nanik,Kusumastuti, Ella,Alighiri, Dante,Rohmawati, Baiti,Lusiana, Retno Ariadi
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p. 399 - 403
(2019/06/05)
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- Discovery of a novel series of α-terpineol derivatives as promising anti-asthmatic agents: Their design, synthesis, and biological evaluation
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A series of novel α-terpineol derivatives were designed and synthesized through structural derivatization of the tertiary hydroxyl moiety or reduction of the double bond. Of the resulting compounds, eight compounds enhanced relaxation of airway smooth muscle (ASM) compared to the α-terpineol precursor, and four compounds (4a, 4d, 4e, and 4i)were superior or comparable to aminophylline at a concentration of 0.75 mmol/L. Assays for 3′-5′-Cyclic adenosine monophpsphate (cAMP) activation revealed that some representative α-terpineol derivatives in this series were capable of upregulating the level of cAMP in ASM cells. Further in vivo investigation using the asthmatic rat model, illustrated that treatment with the compounds 4a and 4e resulted in significantly lowered lung resistance (RL) and enhanced dynamic lung compliance (Cldyn), two important parameters for lung fuction. Moreover, treatment with 4e downregulated the levels of both IL-4 and IL-17. Due to its several favorable physiological functions, including ASM relaxation activity, cAMP activation capability, and in vivo anti-asthmatic efficacy, 4e is a promising remedy for bronchial asthma, meriting extensive development.
- Zhu, Wanping,Liu, Xia,Wang, Yuji,Tong, Yeling,Hu, Yongzhou
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p. 419 - 425
(2017/12/07)
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- M -C2B10H11HgCl/AgOTf-Catalyzed Reaction for Reductive Deoxygenation
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A m -C2B10H11HgCl/AgOTf-catalyzed reaction of allyl silyl ethers with N -Boc- N ′-tosylhydrazine has been developed. Under mild conditions, the resulting allyl hydrazine products were transformed into naked alkenes in good yield. Furthermore, the used m -C2B10H11HgCl could be recovered quantitatively.
- Yamasaki, Naoto,Kanno, Marina,Sakamoto, Kyohei,Kasai, Yusuke,Imagawa, Hiroshi,Yamamoto, Hirofumi
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p. 169 - 175
(2018/03/26)
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- Terpene Cyclizations inside a Supramolecular Catalyst: Leaving-Group-Controlled Product Selectivity and Mechanistic Studies
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The tail-to-head terpene cyclization is arguably one of the most complex reactions found in nature. The hydrogen-bond-based resorcinarene capsule represents the first man-made enzyme-like catalyst that is capable of catalyzing this reaction. Based on noncovalent interactions between the capsule and the substrate, the product selectivity can be tuned by using different leaving groups. A detailed mechanistic investigation was performed to elucidate the reaction mechanism. For the cyclization of geranyl acetate, it was found that the cleavage of the leaving group is the rate-determining step. Furthermore, the studies revealed that trace amounts of acid are required as cocatalyst. A series of control experiments demonstrate that a synergistic interplay between the supramolecular capsule and the acid traces is required for catalytic activity.
- Zhang, Qi,Catti, Lorenzo,Pleiss, Jürgen,Tiefenbacher, Konrad
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supporting information
p. 11482 - 11492
(2017/08/30)
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- Proton-gradient-transfer acid complexes and their catalytic performance for the synthesis of geranyl acetate
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Special proton-gradient-transfer acid complexes (PGTACs) in which the bonded protons are not equivalent and have gradients in transfer ability, acidity, and reactivity were reported. The acidity gradient of the protons gave the PGTACs excellent catalytic activity and selectivity in the esterification of terpenols. These PGTACs are “reaction-induced self-separation catalysts” and can be easily reused. The kinetics with PGTACs as catalyst in the esterification of geraniol were also studied for use in engineering design.
- Chen, Yongle,Ding, Shiya,Zheng, Wentao,Zhang, Yiyang,Wu, Youting,Hu, Xingbang
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p. 2114 - 2121
(2017/01/16)
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- Heteropoly acid catalysts for the synthesis of fragrance compounds from bio-renewables: Acetylation of nopol and terpenic alcohols
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The cesium salt of tungstophosphoric heteropoly acid, Cs2.5H0.5PW12O40, is an active and environmentally friendly heterogeneous catalyst for the liquid-phase acetylation of nopol and several biomass-derived terpenic alcohols (i.e., α-terpineol, nerol, geraniol, linalool, menthol, isoborneol, perillyl alcohol, carveol, isopulegol, carvacrol and nerolidol) with acetic anhydride. The resulting flavor and fragrance acetic esters, which are widely used in perfumery, household and food products, are obtained in good to excellent yields. The reactions occur at room temperature with low catalyst loadings without substantial catalyst leaching and can be performed with stoichiometric amounts of an acetylating agent in solvent free systems.
- Costa, Vinicius V.,Da Silva Rocha, Kelly A.,Oliveira, Luiz C. A.,Kozhevnikova, Elena F.,Kozhevnikov, Ivan V.,Gusevskaya, Elena V.
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p. 43217 - 43222
(2016/05/24)
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- Α-terpineol fatty acid ester derivatives and use
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The invention belongs to the technical field of medicine and discloses alpha-terpineol aliphatic ester and a preparation with the compound. The alpha-terpineol aliphatic ester is formed by alpha-terpineol and fatty acid after esterification reaction. According to a method, first, fatty acid and thionyl chloride react to prepare acyl chloride, and then acyl chloride and alpha-terpineol react to prepare the alpha-terpineol aliphatic ester. The alpha-terpineol ester can be used as penetration enhancers to be used for external preparations of patching agents, Cataplasm, ointment agents, gel agents and the like, accordingly, the percutaneous absorptive amount of medicine is improved, and the alpha-terpineol aliphatic ester is good percutaneous absorptive penetration enhancers and has wide application prospect.
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Paragraph 0041; 0042
(2017/03/18)
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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 0051; 0052; 0053
(2017/01/26)
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- Unravelling transition metal-catalyzed terpenic alcohol esterification: A straightforward process for the synthesis of fragrances
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Iron nitrate is a simple and commercially available Lewis acid and is demonstrated to be able to catalyze β-citronellol esterification with acetic acid, achieving high conversion and ester selectivity (ca. 80 and 70%, respectively), within shorter reaction times than those reported in the literature. To the best of our knowledge, this is the first report of a terpenic alcohol esterification reaction catalyzed by Fe(NO3)3. This process is an attractive alternative to the slow and expensive enzymatic processes commonly used in terpenic alcohol esterification. Moreover, it avoids the undesirable steps of neutralizing the products, which are always required in mineral acid-catalyzed reactions. We have performed a study of the activity of different metal Lewis acid catalysts, and found that their efficiency is directly linked to the ability of the metal cation to generate H+ ions from acetic acid ionization. The measurement of pH as well as the conversions achieved in the reactions allowed us to obtain the following trend: Fe(NO3)3 > Al(NO3)3 > Cu(NO3)2 > Ni(NO3)2 > Zn(NO3)2 > Mn(NO3)2 > Co(NO3)2 > LiNO3. The first three are recognized as stronger Lewis acids and they generate more acidic solutions. When we carried out reactions with different iron salts, it was possible to conclude that the type of anion affects the solubility of the catalyst, as well as the conversion and selectivity of the process. Fe2(SO4)3 and FeSO4 were insoluble and less active. Conversely, though they were equally soluble, Fe(NO3)3 was more selective for the formation of β-citronellyl acetate than FeCl3. We assessed the effects of the main reaction variables such as reactant stoichiometry, temperature, and catalyst concentration. In addition to citronellol, we investigated the efficiency of the iron(iii) catalyst in the solvent free esterification of several terpenic alcohols (geraniol, nerol, linalool, α-terpineol) as well as other carboxylic acids.
- Da Silva,Ayala
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p. 3197 - 3207
(2016/05/24)
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- Α- [...] enol derivative and its preparation method and application
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The invention discloses alpha-terpineol derivatives, the structure of which is shown as the formula (II), wherein R or H is C1-C5 alkyl. The alpha-terpineol derivatives can be obtained by performing esterification reaction on a raw material alpha-terpineol with acid or acid anhydride at the temperature of 18-30DEG C under the action of 4-methylbenzenesulfonyl chloride. The invention further discloses applications of the alpha-terpineol derivatives in preparing antiasthmatic drugs, carboxylic ester prodrug formed by introducing carboxylic ester on the hydroxyl of the alpha-terpineol derivatives can be slowly hydrolyzed in a human body to release parent drug and further prolong the curative effect and the acting time, in addition the bioavailability can be improved, and the antiasthma activity can be further enhanced.
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Paragraph 0035; 0036
(2017/05/03)
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- Synthesis of terpinyl acetate using octadecylamine ethoxylate ionic liquids as catalysts
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Terpinyl acetate, an important natural flavor, can be synthesized by esterification of α-pinene with acetic acid under acidic conditions. In this work, seven acidic ionic liquids were first synthesized, using octadecylamine ethoxylates (AC 1810, AC 1815, AC 1820, and AC 1830) as the cations, and characterized by FT-IR, 1H NMR, and 13C NMR spectroscopy. The ionic liquids were then used as catalysts in the synthesis of terpinyl acetate. The effect of preparation conditions on catalyst performance was examined. It was found that the acidic ionic liquid 1-(3-sulfonic acid)propyl-3-poly(ethylene glycol) octadecylamine polyoxyethylene ether tetrafluoroborate ([PAC1815]+[BF4]-) was an excellent catalyst for synthesis of terpinyl acetate. The effects of the conditions used for preparation of terpinyl acetate were examined in detail, and the optimum preparation conditions were obtained. Under the optimum conditions, the yield of terpinyl acetate reached 35.70 %. When the catalyst was reused for the 5th time, the yield of terpinyl acetate was still 32.00 %. The results showed that effective separation and recycling of catalyst could contribute to developing a new strategy for synthesis of terpinyl acetate.
- Li, Lu,Liu, Shiwei,Shi, Yanjing,Yu, Shitao,Xie, Congxia,Qi, Chunjie
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p. 2095 - 2105
(2013/06/05)
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- ANTIMICROBIAL COMPOSITION COMPRISING THYMOL AND A TERPINYL DERIVATIVE
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The present invention relates to an antimicrobial composition and a method for disinfection involving the antimicrobial composition. It particularly relates to an antimicrobial composition for personal cleaning, oral care or hard surface cleaning applications. It was found that compositions comprising thymol, selected terpinyl derivatives and a carrier provide synergistic antimicrobial action. In a preferred aspect the composition also comprises 1 to 80 %-wt of surfactant.
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Page/Page column 34
(2013/03/26)
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- Microwave-assisted α-pinene acidic catalytic isomerisation
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A comparative study of microwave assisted α-pinene acidic catalytic isomerisation reactions with near-critical water procedure under microwave irradiation is presented. This study can be performed because in both cases the mechanism is similar, namely an acidiccatalyzed rearrangement. The non-critical method technique is milder using a lower temperature and pressure and a shorter reaction time than near-critical water conditions. The general aspect of the selectivity of the reaction products is changed, being higher for α-terpinolene and γ-terpinolene and lower for limonene and camphene compared to the non-critical conditions.
- Szuecs-Balazs, Jozsef Zsolt,Coros, Maria,Molnar, Diana,Vlassa, Mircea
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p. 209 - 213
(2013/03/13)
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- Liquid phase acetoxylation of α-pinene over Amberlyst-70 ion-exchange resin
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Heterogeneously-catalyzed and solvent-catalyzed liquid phase acetoxylation of α-pinene with acetic acid acting as both a solvent and a reagent was studied. Both solvent-catalyzed and catalytic experiments were carried out and various reaction conditions were studied. The influence of temperature, pressure, solvent and gas milieu were taken into account. Bornyl, fenchyl, verbenyl as well as α-terpinyl acetates, limonene, camphene and γ-terpinene were found among reaction products. The addition of the catalyst allowed for maximization of the yield of bornyl acetate. The predominant products obtained were α-terpinyl, verbenyl and bornyl acetates. The reaction pathways were identified and evaluated. The aim of this work was to study the feasibility of batch acetoxylation of α-pinene. The analysis of the complex product distribution is not trivial and, consequently, resolving the reaction network was important. The optimized reaction conditions were searched for aiming at an efficient conversion of α-pinene to a mixture of valuable products.
- Golets,Ajaikumar,Blomberg,Grundberg,W?rn?,Salmi,Mikkola
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scheme or table
p. 43 - 50
(2012/10/18)
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- P-Toluenesulfonyl chloride as a new and effective catalyst for acetylation and formylation of hydroxyl compounds under mild conditions
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The catalytic application of p-toluenesulfonyl chloride for efficient acetylation of various types of alcohols and phenols with acetic anhydride in solvent-free conditions is reported. Also structurally diverse alcohols were formylated using formic acid based on the use of catalytic amount of p-toluenesulfonyl chloride under solvent-free condition. The reactions were carried out in short reaction time and in good to excellent yields at room temperature.
- Khazaei, Ardeshir,Rostami, Amin,Mantashlo, Fatemeh
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experimental part
p. 1430 - 1434
(2011/10/08)
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- Process for making terpene esters
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A process for making terpene esters is disclosed. Reaction of a terpene alcohol with acetic anhydride in the presence of a high-boiling amine provides a terpene ester. Acetic acid, which is distilled from the reaction mixture as it forms can be recovered. The terpene ester is distilled from the high-boiling amine to provide a product that is substantially free of nitrogen-containing impurities. The reaction mixture can be reused for subsequent acylations. The simple, economical process gives high-quality terpene esters while avoiding waste-disposal issues of other common acylation procedures.
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Page/Page column 6
(2008/06/13)
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- A highly selective, high-speed, and hydrolysis-free O-acylation in subcritical water in the absence of a catalyst
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(Chemical Equation Presented) Fast and furious: A wide range of alcohols are acylated by acetic anhydride, in the absence of catalyst, in subcritical water in a flow-type microreaction system. The esters are selectively produced in high yields at temperatures of 200 to 250°C. Varying the amount of acetic anhydride added with respect to the alcohols allows the regioselective acylation of one or both hydroxy groups of various dihydroxy compounds (see picture).
- Sato, Masahiro,Matsushima, Keiichiro,Kawanami, Hajime,Ikuhsima, Yutaka
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p. 6284 - 6288
(2008/04/05)
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- Microwave-assisted NiCl2 promoted acylation of alcohols
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A microwave oven acylation of alcohols by carboxylic acid anhydrides has been developed. NiCl2 has been proven an efficient catalyst for the acylation of primary, secondary, and tertiary alcohols and phenols under microwave conditions.
- Constantinou-Kokotou, Violetta,Peristeraki, Anna
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p. 4227 - 4232
(2007/10/03)
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- Aluminium dodecatungstophosphate (AlPW12O40) as a highly efficient catalyst for the selective acetylation of -OH, -SH and -NH2 functional groups in the absence of solvent at room temperature
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AlPW12O40 was found to be an effective catalyst for the selective acetylation of alcohols, thiols, and amines in the absence of solvent at room temperature.
- Firouzabadi, Habib,Iranpoor, Nasser,Nowrouzi, Farhad,Amani, Kamal
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p. 764 - 765
(2007/10/03)
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- An Efficient Acylation of Tertiary Alcohols with Isopropenyl Acetate Mediated by an Oxime Ester and Cp*2Sm(thf)2
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An efficient method for the acylation of tertiary alcohols with isopropenyl acetate (1) by the use of an oxime and Cp*2Sm(thf)2 as catalyst was developed. Thus, various types of tertiary alcohols could be acylated with 1 in the presence of a catalytic amount of cyclohexanone oxime acetate (2) and Cp*2Sm(thf)2 under mild conditions to form the corresponding acetates in excellent yields. Acid-sensitive terpene alcohols such as linalool were successfully acetylated by the present method to give acetyl linalool in quantitative yield. This method enables an alternative acylation of tertiary alcohols under acid-free conditions.
- Tashiro, Daisuke,Kawasaki, Yumi,Sakaguchi, Satoshi,Ishii, Yasutaka
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p. 8141 - 8144
(2007/10/03)
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- Sonochemical acetylation reactions of tertiary alkyl halides
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A simple method for the acetylation of tertiary alkyl halides is described. The reaction was carried out using zinc acetate in presence of a phase transfer catalyst in an ultrasonic bath.
- Jayasree,Rao, J. Madhusudana
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p. 1103 - 1107
(2007/10/03)
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- INVESTIGATION OF THE SYNTHESIS OF VERBENYL COMPOUNDS EFFECTIVE ATTRACTANTS OF COCKROACH SPECIES, BY ACYLOXYLATION OF α-PINENE
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The synthesis of verbenyl acetate (Ia) and propionate (Ib) was inestigated by acyloxylation of α-pinene with lead(IV) acetate (LTA), lead(IV) propionate (LTP), mercury(II) acetate (MA) and iodosobenzene diacetate (IBDA) in neutral and acidic medium.The neutral medium is better for the formation of Ia and Ib, because the acidic medium helps the opening of cyclobutane ring of α-pinene.These methods can be used for large scale preparation of insect attractants to cockroach species (Blatella germanica, Blatella orientalis and Periplaneta americana).
- Vinczer, Peter,Kajtar-Peredy, Maria,Juvancz, Zoltan,Novak, Lajos,Szantay, Csaba
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p. 1719 - 1730
(2007/10/02)
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- Conversion of Terpenic Compounds to ω-Ketonitriles
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Conversion of unsaturated terpenoids with trisubstituted carbon-carbon double bond into α-aminooximes followed by treatment with phosphorus pentachloride results in the formation of seco-terpenic ω-ketonitriles.
- Tkachev, A.V.,Rukavishnikov, A.V.,Chibirjaev, A.M.,Volodarsky, L.B.
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p. 2123 - 2132
(2007/10/02)
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- NUCLEOPHILIC SUBSTITUTION OF ALKYL HALIDES BY ZINC SALTS-3 PREPARATION OF TERTARY ALKYL ESTERS AND ETHERS UNDER NON-SOLVOLYTIC CONDITIONS
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Zinc salts of carboxylic acids, phenols and alcohols are found to react with tertiary alkyl halides in nonpolar solvents and in presence of a base yielding the corresponding esters and ethers in moderate to good yields.
- Ravindranath, B.,Srinivas, P.
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p. 1623 - 1628
(2007/10/02)
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- Rearrangement of Pinane Derivatives. Part 8. Deamination of 2αH-Pinan-3α-ylamine
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Solvolysis of 2αH-pinan-3α-yl toluene-p-sulphonate has been shown to proceed with concomitant 1,2-hydride shift to give the pinan-2-yl carbocation.Contrary to earlier reports, this species reacts normally to give, in good yield, pinan-2-yl substitution products.In contrast the pinan-3-ylamines react via a similar route, but give much smaller amounts of pinan-2-yl products.The usual reasons for differences between solvolysis and deamination (i.e. the intermediacy of diazonium ions and/or high-energy ions) can be discounted, and possible reasons for the differences in behaviour are discussed.
- Giddings, Rodney M.,Jones-Parry, Richard,Salmon, J. Roger,Whittaker, David
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p. 725 - 728
(2007/10/02)
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- SOLVOLYTIC DISPLACEMENT OF ALKYL HALIDES BY METAL SALTS. PREPARATIVE PROCEDURES FOR ALLYL-, BENZYL- AND TERTIARY ALKYL-OXY DERIVATIVES USING THE ZINC SALTS
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Reaction of allylic, benzylic and tertiary alkyl halides with zinc oxide in protic solvents leads to the formation of the corresponding alcohols, ethers and esters in good yields.The scope and limitations of this reaction have been examined.The possible involvement of ion quadruplets in the reaction is suggested.
- Gurudutt, K. N.,Ravindranath, B.,Srinivas, P.
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p. 1843 - 1846
(2007/10/02)
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