- 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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- Method and Means for Releasing a Terpene Mixture to a Cannabis Flower During Storage
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A method and means for releasing a terpene mixture to a Cannabis flower during storage with may be from a cotton pulp card or a two-way humidity pack with an additional terpene blend for keeping a Cannabis flower fresh while naturally increasing the desired terpene levels. The product is a blend of humidity regulating agents infused with terpenes (plant derived) which allows for the product to be paired with herbal material to increase and maintain the relative humidity, while transferring the flavor/aroma/taste terpenes from the package into the herbal material. There are two embodiments, the first is a Terp Pack+Humidity (“Terp Pack+RH”) which contains a herban material to increase and maintain relative humidity, while releasing the infused terenes, and the second is more simply a Terp Pack (“Terp Pack”) which contains no humidity enhancing material and is only a carrier for releasing the terpene mixture.
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- Nickel-catalyzed reductive deoxygenation of diverse C-O bond-bearing functional groups
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We report a catalytic method for the direct deoxygenation of various C-O bond-containing functional groups. Using a Ni(II) pre-catalyst and silane reducing agent, alcohols, epoxides, and ethers are reduced to the corresponding alkane. Unsaturated species including aldehydes and ketones are also deoxygenated via initial formation of an intermediate silylated alcohol. The reaction is chemoselective for C(sp3)-O bonds, leaving amines, anilines, aryl ethers, alkenes, and nitrogen-containing heterocycles untouched. Applications toward catalytic deuteration, benzyl ether deprotection, and the valorization of biomass-derived feedstocks demonstrate some of the practical aspects of this methodology.
- Cook, Adam,MacLean, Haydn,St. Onge, Piers,Newman, Stephen G.
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p. 13337 - 13347
(2021/11/20)
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- Monoterpenes etherification reactions with alkyl alcohols over cesium partially exchanged Keggin heteropoly salts: effects of catalyst composition
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In this work, cesium partially exchanged Keggin heteropolyacid (HPA) salts were prepared, characterized, and evaluated as solid catalysts in monoterpenes etherification reactions with alkyl alcohols. A comparison of the activity of soluble HPAs and their insoluble cesium salts showed that among three different Keggin anions the phosphotungstate was the most efficient catalyst. Assessments on the effects of the level of the protons exchange by cesium cations demonstrated that Cs2.5H0.5PW12O40 solid salt was the most active and selective phosphotungstate catalyst, converting β-pinene to α-terpinyl methyl ether. The influences of the main reaction parameters such as reaction temperature, time, catalyst load, substrate nature (i.e., alcohols and monoterpenes) were investigated. We have demonstrated that the simultaneous presence of the cesium ions and protons in the catalyst plays an essential role, being the 2.5–0.5 the optimum molar ratio. The Cs2.5H0.5PW12O40 salt was efficiently recovered and reused without loss of catalytic activity. Graphic abstract: [Figure not available: see fulltext.]
- da Silva, Márcio José,Lopes, Neide Paloma Goncalves,Ferreira, Sukarno Olavo,da Silva, Rene Chagas,Natalino, Ricardo,Chaves, Diego Morais,Texeira, Milena Galdino
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p. 153 - 168
(2020/07/21)
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- Thioderivatives of Resorcin[4]arene and Pyrogallol[4]arene: Are Thiols Tolerated in the Self-Assembly Process?
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Three novel thiol bearing resorcin[4]arene and pyrogallol[4]arene derivatives were synthesized. Their properties were studied with regards to self-assembly, disulfide chemistry, and Br?nsted acid catalysis. This work demonstrates that (1) one aromatic thiol on the resorcin[4]arene framework is tolerated in the self-assembly process to a hexameric hydrogen bond-based capsule, (2) thio-derivatized resorcin[4]arene analogs can be covalently linked through disulfides, and (3) the increased acidity of aromatic thio-substituent is not sufficient to replace HCl as cocatalyst for capsule catalyzed terpene cyclizations.
- Nemat, Suren J.,Tiefenbacher, Konrad
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supporting information
p. 6861 - 6865
(2021/09/14)
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- Preparation method of myrcene
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The method uses geraniol and/or nerol and/or linalool as a raw material, uses a palladium source and an organic phosphine as a catalyst to prepare myrcene, and realizes chemical synthesis of myrcene. The method has the advantages of high catalytic efficiency and high product selectivity.
- -
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Paragraph 0043-0044
(2021/11/19)
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- Electro-mediated PhotoRedox Catalysis for Selective C(sp3)–O Cleavages of Phosphinated Alcohols to Carbanions
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We report a novel example of electro-mediated photoredox catalysis (e-PRC) in the reductive cleavage of C(sp3)?O bonds of phosphinated alcohols to alkyl carbanions. As well as deoxygenations, olefinations are reported which are E-selective and can be made Z-selective in a tandem reduction/photosensitization process where both steps are photoelectrochemically promoted. Spectroscopy, computation, and catalyst structural variations reveal that our new naphthalene monoimide-type catalyst allows for an intimate dispersive precomplexation of its radical anion form with the phosphinate substrate, facilitating a reactivity-determining C(sp3)?O cleavage. Surprisingly and in contrast to previously reported photoexcited radical anion chemistries, our conditions tolerate aryl chlorides/bromides and do not give rise to Birch-type reductions.
- Barham, Joshua P.,K?nig, Burkhard,Karl, Tobias A.,Reiter, Sebastian,Tian, Xianhai,Yakubov, Shahboz,de Vivie-Riedle, Regina
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p. 20817 - 20825
(2021/08/18)
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- Enantioselective Tail-to-Head Cyclizations Catalyzed by Dual-Hydrogen-Bond Donors
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Chiral urea derivatives are shown to catalyze enantioselective tail-to-head cyclization reactions of neryl chloride analogues. Experimental data are consistent with a mechanism in which ?-participation by the nucleophilic olefin facilitates chloride ionization and thereby circumvents simple elimination pathways. Kinetic and computational studies support a cooperative mode of catalysis wherein two molecules of the urea catalyst engage the substrate and induce enantioselectivity through selective transition state stabilization.
- Kutateladze, Dennis A.,Strassfeld, Daniel A.,Jacobsen, Eric N.
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supporting information
p. 6951 - 6956
(2020/05/19)
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- Synthesis of isobenzofuran derivatives from renewable 2-carene over halloysite nanotubes
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Condensation of a terpene 2-carene with 4-methoxybenzaldehyde over a range of acid aluminosilicates including halloysite nanotubes (HNT) was studied for as a model for preparation of isobenzofuran derivatives with a pharmaceutical potential. The catalysts were characterized by FTIR with pyridine, UV by adsorption of 2-phenylethylamine from the aqueous phase, SEM, TEM and N2 physisorption. The largest selectivity to the desired product (ca. 70%) over halloysite nanotubes is associated with weak acidity of these catalysts (45 μmol/g), allowing avoiding side isomerization and condensation reactions. Moreover, the highest yield on air-dry HNT clearly indicates that weak Br?nsted sites favored the reaction. On the contrary, over strong Br?nsted and Lewis acids (Amberlyst-15, scandium triflate), the yield of isobenzofurans did not exceed 16% with formation of mainly 2-carene isomerization products. DFT calculations showed that interactions of the aldehyde with cyclopropane moiety of 2-carene giving isobenzofurans are more beneficial than an alternative direct attack of a proton, leading to side reactions. A possibility to reuse of HNT catalyst was confirmed. Overall, halloysite is a highly effective catalyst for production of isobenzofuran compounds based on 2-carene.
- Agabekov, V. E.,Aho, A.,Il'ina, I. V.,Korchagina, D. V.,Kravtsova, A. V.,Li-Zhulanov, N. S.,M?ki-Arvela, P.,Murzin, D. Yu.,Salakhutdinov, N. F.,Sandberg, T.,Sidorenko, A. Yu.,Volcho, K. P.
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- Upcycling a plastic cup: One-pot synthesis of lactate containing metal organic frameworks from polylactic acid
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Waste PLA can be upcycled to metal organic frameworks of potential high value in a one-pot synthesis scheme, where PLA depolymerisation occurs in situ. Three homochiral lactate based frameworks were successfully synthesised and characterised from PLA as a feed source, including ZnBLD. The chiral separation ability of ZnBLD was maintained.
- Slater, Benjamin,Wong, So-On,Duckworth, Andrew,White, Andrew J. P.,Hill, Matthew R.,Ladewig, Bradley P.
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supporting information
p. 7319 - 7322
(2019/06/27)
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- Discovering Monoterpene Catalysis Inside Nanocapsules with Multiscale Modeling and Experiments
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Large-scale production of natural products, such as terpenes, presents a significant scientific and technological challenge. One promising approach to tackle this problem is chemical synthesis inside nanocapsules, although enzyme-like control of such chemistry has not yet been achieved. In order to better understand the complex chemistry inside nanocapsules, we design a multiscale nanoreactor simulation approach. The nanoreactor simulation protocol consists of hybrid quantum mechanics-molecular mechanics-based high temperature Langevin molecular dynamics simulations. Using this approach we model the tail-to-head formation of monoterpenes inside a resorcin[4]arene-based capsule (capsule I). We provide a rationale for the experimentally observed kinetics of monoterpene product formation and product distribution using capsule I, and we explain why additional stable monoterpenes, like camphene, are not observed. On the basis of the in-capsule I simulations, and mechanistic insights, we propose that feeding the capsule with pinene can yield camphene, and this proposal is verified experimentally. This suggests that the capsule may direct the dynamic reaction cascades by virtue of π-cation interactions.
- Pahima, Efrat,Zhang, Qi,Tiefenbacher, Konrad,Major, Dan T.
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p. 6234 - 6246
(2019/04/25)
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- Layer-assembled 3D Bi2WO6 hierarchical architectures by Ti-doping for enhanced visible-light driven photocatalytic and photoelectrochemical performance
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Layer-assembled three-dimensional (3D) catalysis gain substantial attention and widespread application in the field of photocatalysis and solar energy conversion. The 3D hierarchical architecture possesses large surface area and plenty reactive sites which contribute highly in catalysis performance. In this work we report a tetrabutyl titanate (TBT) assisted simultaneous approach of layer-assembled single-unit-cell 3D Bi2WO6 hierarchical architecture by Ti-doping. The Ti-doping beside its morphological effect can also generate crystal defects in the crystal lattice of Bi2WO6, resulting in highly enhanced visible-light driven photocatalytic performance towards highly stable refractory pollutants and profound photoelectrochemical ability. Moreover, the crystal defects mediated by Ti-doping can generate abundant oxygen vacancies which remarkably improve the selective adsorption towards different charges pollutants. Furthermore, the Ti-doping beside its great influence on the electron dynamic and band structure can also introduce the redox couples (Ti3+/Ti4+), resulting in significance enhancement in reactive oxygen species during photocatalytic reaction. The present work provides a valid route for constructing simultaneous approach of layer-assembled 3D hierarchical architecture and Ti-substitution in the crystal structure of Bi2WO6 with great improvement in photocatalytic and photoelectrochemical performance.
- Arif, Muhammad,Zhang, Min,Yao, Jiacheng,Yin, Hongfei,Li, Pengfei,Hussain, Ijaz,Liu, Xiaoheng
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p. 878 - 893
(2019/04/17)
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- Exploring the Keggin-Type Heteropolyacid-Catalyzed Reaction Pathways of the Β-Pinene with Alkyl Alcohols
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Abstract: In this work, we investigated the activity of Keggin heteropolyacid catalysts (i.e., H3PW12O40, H3PMo12O40 and H4SiW12O40) in β-pinene reactions with alkyl alcohols (i.e. methyl, ethyl, propyl, sec-propyl, butyl and sec-butyl alcohols), and exploring the different aspects that drive the selectivity of this process. We have found that carbon skeletal rearrangements and isomerization providing intermediate carbocations that controlling the reaction selectivity. β-pinene was preferentially converted to α-terpinyl ion which undergoes a nucleophilic attack of alcohol providing alkyl alcohol. Bornyl ion was converted to bornyl and fenchyl ethers. The other secondary products were β-pinene isomers obtained from bornyl and α-terpinyl carbocations. Phosphotungstic acid (i.e., H3PW12O40) was the most active catalyst and selective toward the main product (α-terpinyl alkyl ether); the highest conversion (ca. 96%) and ether selectivity (ca. 61%) was achieved in the reactions with β-pinene. Although having also been alkoxylate, α-pinene was less reactive (ca. 40%), while camphene and limonene remained unreactive under reaction conditions studied. An increase of temperature resulted in an improvement on conversion of β-pinene and selectivity toward α-terpinyl methyl ether. Similarly, the H3PW12O40 concentration played a crucial role on reaction selectivity. This work presents positive features such as a short reaction time, high atom economy, mild reaction conditions (i.e., low temperature and room pressure). Even though soluble the catalyst was easily recovered by liquid -liquid extraction and efficiently reused. Graphical Abstract: [Figure not available: see fulltext.].
- Polo, Henrique Priori,Lopes, Neide Paloma Goncalves,da Silva, Márcio José
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p. 2844 - 2853
(2019/05/28)
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- Thermal Behavior Analysis of Two Synthesized Flavor Precursors of N-alkylpyrrole Derivatives
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To expand the library of pyrrole-containing flavor precursors, two new flavor precursors—methyl N-benzyl-2-methyl-5-formylpyrrole-3-carboxylate (NBMF) and methyl N-butyl-2-methyl-5-formylpyrrole-3-carboxylate (NUMF)—were synthesized by cyclization, oxidation, and alkylation reactions. Thermogravimetry (TG), differential scanning calorimeter, and pyrolysis–gas chromatography/mass spectrometry were utilized to analyze the thermal degradation behavior and thermal degradation products of NBMF and NUMF. The TG-DTG curve indicated that the maximum mass loss rates of NBMF and NUMF appear at 310 and 268°C, respectively. The largest peaks of NBMF and NUMF showed by the differential scanning calorimeter curve were 315 and 274°C, respectively. Pyrolysis–gas chromatography/mass spectrometry detected small molecule fragrance compounds appeared during thermal degradation, such as 2-methylpyrrole, 1-methylpyrrole-2-carboxylic acid methyl ester, limonene, and methyl formate. Finally, the thermal degradation mechanism of NBMF and NUMF was discussed, which provided a theoretical basis for their application in tobacco flavoring additives.
- Ai, Lvye,Liu, Mengzhen,Ji, Xiaoming,Lai, Miao,Zhao, Mingqin,Ren, Tianbao
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p. 2389 - 2397
(2019/08/01)
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- Method for producing limonene by taking acidic ionic liquid loaded zirconia microcapsules as catalyst
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The invention provides a method for producing limonene by taking acidic ionic liquid loaded zirconia microcapsules as a catalyst. The method comprises the following steps: adding zirconium oxynitrateinto water, carrying out thorough dissolving, dropwise adding ammonia water to adjust the aqueous solution to be alkaline, carrying out room-temperature standing aging, and carrying out filtration, washing and baking, so as to obtain zirconium hydroxide; grinding zirconium hydroxide, then, mixing the ground zirconium hydroxide with a pore former and a sizing agent, then, carrying out compression sizing, and carrying out calcining, so as to obtain a porous zirconia carrier; adding porous zirconia into the acidic ionic liquid for thorough dipping, carrying out filtrating, sprinkling a gelatin-containing mixed solution, and carrying out baking, so as to obtain the acidic ionic liquid loaded zirconia microcapsules; and subjecting alpha-pinene, which serves as a raw material, to a reaction in aliquid-solid multiphase stirred reactor or fixed-bed reactor under normal pressure in the presence of the acidic ionic liquid loaded zirconia microcapsules, thereby obtaining the limonene. The catalyst has high selectivity to alpha-pinene isomerized principal products, the yield of limonene is high, the reaction conditions are mild, the corrosiveness to equipment is low, and thus, the method is environmentally friendly and safe.
- -
-
Paragraph 0023; 0027; 0032; 0037; 0042; 0047; 0052
(2018/06/16)
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- A porous Br?nsted superacid as an efficient and durable solid catalyst
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The development of catalysts able to assist industrial chemical transformations is a topic of high importance. In view of the versatile catalytic capabilities of acid catalysts, extensive research efforts are being made to develop porous superacid materials with a high density of accessible active sites to replace molecular acid catalysts. Herein, we report the rational development of a porous Br?nsted superacid by combining important elements that target high strength acidity into one material, as demonstrated by grafting the sulfonic acid group onto a highly fluorinated porous framework, where the acid strength and stability are greatly enhanced by an electron-withdrawing environment provided by the polymer backbone, reminiscent of that seen in Nafion resin. In addition, the densely arranged acid groups that are confined in the three-dimensional nanospace facilitate the transfer of hydrons, thereby further increasing the acidity. By virtue of the pore structure and strong acidity, this system exhibits excellent performance for a wide range of reactions, far outperforming commercial acid resins under repeated batch and flow reaction conditions. Our findings demonstrate how this synthetic approach may instruct the future design of heterogeneous acid catalysts with advantageous reaction capabilities and stability.
- Sun, Qi,Hu, Kewei,Leng, Kunyue,Yi, Xianfeng,Aguila, Briana,Sun, Yinyong,Zheng, Anmin,Meng, Xiangju,Ma, Shengqian,Xiao, Feng-Shou
-
supporting information
p. 18712 - 18719
(2018/10/15)
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- Transition metal triflate catalyzed conversion of alcohols, ethers and esters to olefins
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Herein, we report an efficient transition metal triflate catalyzed approach to convert biomass-based compounds, such as monoterpene alcohols, sugar alcohols, octyl acetate and tea tree oil, to their corresponding olefins in high yields. The reaction proceeds through C-O bond cleavage under solvent-free conditions, where the catalytic activity is determined by the oxophilicity and the Lewis acidity of the metal catalyst. In addition, we demonstrate how the oxygen containing functionality affects the formation of the olefins. Furthermore, the robustness of the used metal triflate catalysts, Fe(OTf)3 and Hf(OTf)4, is highlighted by their ability to convert an over 2400-fold excess of 2-octanol to octenes in high isolated yields.
- Keskiv?li,Parviainen,Lagerblom,Repo
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p. 15111 - 15118
(2018/05/04)
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- SnCl2-catalyzed synthesis of carbamates from renewable origin alcohols
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Effects of structure and reactivity of renewable origin alcohols in the conversion and selectivity of the SnCl2-catalyzed reactions in the presence and absence of urea were assessed. Convenient simple and suitable method for the synthesis of carbamates from renewable origin alcohols and urea in one-step are provided. We have assessed the activity of SnCl2 catalyst, a commercially affordable Lewis acid, in reactions of urea alcoholysis with different natural origin alcohols (geranyl, neryl, bornyl, cinnamyl, α-terpinyl and benzyl alcohols), aiming to synthesize carbamates, which are biologically active compounds, building blocks in organic synthesis and raw material to synthesize polyurethanes. The low cost of urea, the water tolerant catalyst and phosgene free reaction are positive aspects of this carbamates synthesis process. The different reaction pathways were assessed. A mechanism was proposed based on FT-IR experiments and experimental data.
- da Silva, Márcio José,Chaves, Diego Morais
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p. 1169 - 1180
(2019/01/28)
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- Synthesis of Trisubstituted Alkenyl Boronic Esters from Alkenes Using the Boryl-Heck Reaction
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The direct borylation of disubstituted alkenes is reported. These conditions allow for the conversion of a variety 1,1- and 1,2-disubstituted alkenes to trisubstituted alkenyl boronic esters with outstanding yields and excellent E/Z selectivities. The utility of this reaction has been demonstrated with several downstream functionalization reactions, which allow access to diverse, stereodefined, functionalized olefins. Mechanistic studies are consistent with a boryl-Heck pathway.
- Reid, William B.,Watson, Donald A.
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supporting information
p. 6832 - 6835
(2018/10/24)
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- Photocatalytic Transfer Hydrogenolysis of Allylic Alcohols on Pd/TiO2: A Shortcut to (S)-(+)-Lavandulol
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We report herein a regio- and stereoselective photocatalytic hydrogenolysis of allylic alcohols to form unsaturated hydrocarbons employing a palladium(II)-loaded titanium oxide; the reaction proceeds at room temperature under light irradiation without stoichiometric generation of salt wastes. Olefin and saturated alcohol moieties tolerated the reaction conditions. Hydrogen atoms were selectively incorporated into less sterically congested carbons of the allylic functionalities. This protocol allowed a short-step synthesis of (S)-(+)-lavandulol from (R)-(?)-carvone by avoiding otherwise necessary protection/deprotection steps.
- Takada, Yuki,Caner, Joaquim,Kaliyamoorthy, Selvam,Naka, Hiroshi,Saito, Susumu
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supporting information
p. 18025 - 18032
(2017/12/08)
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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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- Bifunctional catalyst Pd-Al-MCM-41 for efficient dimerization-hydrogenation of β-pinene in one pot
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A new type of bimetallic palladium and aluminum incorporated mobile crystalline materials (Pd-Al-MCM-41) as bifunctional catalysts has been hydrothermally synthesized. Characterization shows that these molecular materials exhibit an ordered mesoporous structure, high surface area and a good dispersion of palladium in the frame. The catalytic activity of the Pd-Al-MCM-41 for the dimerization-hydrogenation reaction system of β-pinene in one pot has been systematically studied. Pd0.5-Al30-MCM-41 (SiO2/Al2O3 = 30, 0.5 wt% palladium content) was found to be the best catalyst which gave a dimer yield of up to 64.7%. It is worth noting that palladium shows a good synergic catalytic effect with aluminum in the dimerization reaction and enhances the dimerization yield. Furthermore, the bifunctional catalyst displayed a good activity over 4 runs.
- Zhang, Song,Xu, Chao,Zhai, Guoqing,Zhao, Mingliang,Xian, Mo,Jia, Yuxiang,Yu, Zongjiang,Liu, Fusheng,Jian, Fangfang,Sun, Weizhi
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p. 47539 - 47546
(2017/10/19)
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- Photocaged Hydrocarbons, Aldehydes, Ketones, Enones, and Carboxylic Acids and Esters that Release by the Norrish II Cleavage Protocol and Beyond: Controlled Photoinduced Fragrance Release
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Five families of caged fragrance compounds that allow the storage and release of the following small volatile organic molecules are described: terpene hydrocarbons, aldehydes, ketones, Michael-type α,β-unsaturated enones, and carboxylic acids and esters. These caged molecules are released by photoexcitation via carbonyl-directed hydrogen-transfer processes and subsequent C-C bond cleavage (Norrish Type II) or by didenitrogenation of diazirines.
- Griesbeck, Axel G.,Porschen, Bj?rn,Kropf, Christian,Landes, Agnieszka,Hinze, Olga,Huchel, Ursula,Gerke, Thomas
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p. 539 - 553
(2017/01/25)
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- High density fuels from oxygenated terpenoids
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A method for the efficient synthesis of useful deoxygenated terpenoids from an abundant renewable source, using catalytic conversion of oxygenated terpenoids. Oxygenated terpenoids such as 1,4-cineole and 1,8-cineole are, for example, major components of turpentine and essential oils. These oxygenated terpenoids can also be produced from sugars via a biosynthetic approach. Catalytic deoxygenation of these substrates can be used to efficiently generate commercially important chemicals and high density fuels for turbine or diesel propulsion.
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Page/Page column 7; 8
(2017/07/06)
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- Method for preparing limonene from 3-carene
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The invention discloses a method for preparing limonene from 3-carene. The method comprises the following steps: (1) preparing terpin from 3-carene in the presence of sulfuric acid, wherein the reaction temperature is kept at 15-35 DEG C; and (2) preparing limonene from the terpin in the presence of sulfuric acid, wherein the reaction temperature is kept at 0-10 DEG C. The invention aims at providing a method for preparing limonene from 3-carene, wherein in the method, limonene is prepared from cheap 3-carene, the conversion rate is high while the preparation flow is relatively simple, and the prepared limonene is separated from other byproducts relatively easily.
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Paragraph 0017; 0018; 0019; 0020; 0021; 0022
(2017/04/27)
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- Converting S-limonene synthase to pinene or phellandrene synthases reveals the plasticity of the active site
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S-limonene synthase is a model monoterpene synthase that cyclizes geranyl pyrophosphate (GPP) to form S-limonene. It is a relatively specific enzyme as the majority of its products are composed of limonene. In this study, we converted it to pinene or phellandrene synthases after introducing N345A/L423A/S454A or N345I mutations. Further studies on N345 suggest the polarity of this residue plays a critical role in limonene production by stabilizing the terpinyl cation intermediate. If it is mutated to a non-polar residue, further cyclization or hydride shifts occurs so the carbocation migrates towards the pyrophosphate, leading to the production of pinene or phellandrene. On the other hand, mutant enzymes that still possess a polar residue at this position produce limonene as the major product. N345 is not the only polar residue that may stabilize the terpinyl cation because it is not strictly conserved among limonene synthases across species and there are also several other polar residues in this area. These residues could form a “polar pocket” that may collectively play this stabilizing role. Our study provides important insights into the catalytic mechanism of limonene synthases. Furthermore, it also has wider implications on the evolution of terpene synthases.
- Xu, Jinkun,Ai, Ying,Wang, Jianhui,Xu, Jingwei,Zhang, Yongkang,Yang, Dong
-
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- Catalytic and physicochemical properties of modified natural clinoptilolite
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A natural specimen from the deposit at Ku?in (Slovakia), rich in clinoptilolite type zeolite, was dealuminated using HCl solutions of increasing concentration (0.05-11.5 M). The samples were characterized by XRD, sorption of nitrogen, TPD of ammonia, FT IR and NMR spectroscopies. The preparations modified under mild conditions (acid concentration, temperature of dealumination) retained largely their crystallinity and acidity, and were active in the liquid phase isomerization of α-pinene. Upon more severe treatments, the samples became partially amorphous and lost their catalytic activity. The kinetics of α-pinene isomerization was studied over the most active catalysts. The reaction rate constants and apparent energies of activation were obtained. Initial reaction rates over the clinoptilolite type catalysts were compared with other acidic catalysts, including ferrierite-type zeolites.
- Dziedzicka, Anna,Sulikowski, Bogdan,Ruggiero-Miko?ajczyk, Ma?gorzata
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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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- PHOTOLABILE PRO-FRAGRANCES
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The present invention relates to a method for producing photocleavable scent precursors, to products containing the scent precursors, and to the use of the scent precursors for prolonging the scent impression in the product and on surfaces treated with the product.
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-
Paragraph 0167-0169
(2017/01/12)
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- PHOTOLABILE PRO-FRAGRANCES
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The present invention relates to a method for producing photocleavable scent precursors, to products containing the scent precursors, and to the use of the scent precursors for prolonging the scent impression in the product and on surfaces treated with the product.
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Paragraph 0122
(2016/04/09)
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- Hybrid catalysts based on platinum and palladium nanoparticles for the hydrogenation of terpenes under slurry conditions
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Catalysts based on platinum and palladium nanoparticles immobilized in mesoporous phenolformaldehyde polymers modified with sulfo groups have been used for the hydrogenation of a number of terpenes, such as (S)-(–)-limonene, α-terpinene, γ-terpinene, and terpinolene. It has been found that Pd-containing catalysts exhibit higher activity in the exhaustive hydrogenation of terpenes, whereas Pt-containing catalysts have high selectivity for p-menthene.
- Karakhanov,Boronoev,Subbotina,Zolotukhina,Maximov,Filippova, T. Yu.
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p. 1114 - 1122
(2017/02/15)
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- Acidic functionalized ionic liquids as catalyst for the isomerization of α-pinene to camphene
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An acidic functionalized ionic liquids (ILs) [HSO3-(CH2)3-NEt3]Cl-ZnCl2 was synthesized and used to catalyze the isomerization of α-pinene in a homogeneous system. The optimum conditions for isomerization were obtained as follows: n(α-pinene):n(ILs) = 9:1, reaction temperature 140 °C, and reaction time 4 h, α-pinene 0.04 mol. Under the optimal conditions, the conversion of α-pinene was 97.6 % and the selectivity for camphene could reach 64.8 %. In addition, the catalyst could be easily separated by centrifugation after the isomerization completely finished. When the ILs were repeatedly used for four times, the conversion of α-pinene and the selectivity for camphene were still excellent, indicating the superb recycle ability of the acidic functionalized ILs catalyst.
- Liu, Yue,Li, Lu,Xie, Cong Xia
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p. 559 - 569
(2016/04/26)
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- Sonocatalytic degradation of a textile dye over Gd-doped ZnO nanoparticles synthesized through sonochemical process
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The present study was performed to sonochemically synthesize GdxZn1-xO (x = 0-0.1) nanoparticles for sonocatalysis of Acid Orange 7 (AO7) in an aqueous medium. The results of X-ray diffraction (XRD), scanning electron microscopy (SEM
- Khataee, Alireza,Soltani, Reza Darvishi Cheshmeh,Karimi, Atefeh,Joo, Sang Woo
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p. 219 - 230
(2015/02/19)
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- Selective methoxylation of α-pinene to α-terpinyl methyl ether over Al3+ ion-exchanged clays
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In this study, we report the use of clay-based catalysts in the methoxylation of α-pinene, for the selective synthesis of α-terpinyl methyl ether, TME. The main reaction products and intermediates were identified by GC-MS. The reaction conditions (stirring rate and catalyst load) that afford a kinetic regime were established. SAz-1 (Cheto, Arizona, USA) source clay and a montmorillonite (SD) from Porto Santo, Madeira Archipelago, Portugal, were modified by ion-exchange with Al3+ to produce catalysts with markedly different acidities and textural properties. The catalysts based on the high layer-charge SAz-1 montmorillonite proved to be the most active. Ion-exchange with Al3+, followed by thermal activation at 150°C, afforded the highest number of Br?nsted acid sites - a significant proportion of which were located in the clay gallery - and this coincided with the maximum catalytic activity. The influence of various reaction conditions, to maximize α-pinene conversion and selectivity, was studied over AlSAz-1. When the reaction was performed for 1 h at 60°C, the conversion reached 65% with 65% selectivity towards the mono-ether, TME. Similar conversions and selectivities required up to 50 h over zeolites and other solid acid catalysts. The kinetic dependencies of this reaction on temperature and reagent concentration, over the selected clays were also investigated. It was established that, in the temperature and reagent concentration regime studied, the reaction was first order with respect to α-pinene. The apparent activation energies over the two catalysts, calculated from Arrhenius plots, were almost identical at 72 kJ mol-1.
- Catrinescu,Fernandes,Castilho,Breen
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p. 171 - 179
(2015/05/05)
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- METHOD FOR PRODUCING ORGANIC COMPOUND
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PROBLEM TO BE SOLVED: To provide a method of subjecting a compound having on one carbon atom a carbon atom constituting a carbon-carbon double bond and a functional group such as a hydroxyl group to a reductive reaction condition and producing an organic compound having the functional group substituted with a hydrogen atom. SOLUTION: There is provided a method for producing a compound represented by a formula (50) from a raw material compound represented by a formula (10). The method includes a step of irradiating a reaction system with light, the reaction system comprising the raw material compound, a hydrogen source compound, and a catalyst having a palladium component supported by a carrier containing titanium oxide. (R11 to R15 are a hydrogen atom, a hydrocarbon group having 1 to 40 carbon atoms which may have a cyclic structure or a derivative group thereof, or a heteroatom-containing group having 1 to 20 carbon atoms which may have a cyclic structure or a derivative group thereof; and R16 is a hydrogen atom, a hydrocarbon group having 1 to 40 carbon atoms or an acyl group having 1 to 20 carbon atoms which may have a cyclic structure, or -CH(CH2OH)2).) COPYRIGHT: (C)2015,JPO&INPIT
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Paragraph 0084-0087; 0097; 0129; 0137; 0138
(2018/10/16)
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- Isotope sensitive branching and kinetic isotope effects to analyse multiproduct terpenoid synthases from Zea mays
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Multiproduct terpene synthases TPS4-B73 and TPS5-Delprim from Zea mays exhibit isotopically sensitive branching in the formation of mono- and sesquiterpene volatiles. The impact of the kinetic isotope effects and the stabilization of the reactive intermediates by hyperconjugation along with the shift of products from alkenes to alcohols are discussed.
- Gatto, Nathalie,Vattekkatte, Abith,K?llner, Tobias,Degenhardt, J?rg,Gershenzon, Jonathan,Boland, Wilhelm
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supporting information
p. 3797 - 3800
(2015/03/30)
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- Hydrothermal synthesis of single-crystalline mesoporous beta zeolite assisted by N-methyl-2-pyrrolidone
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Highly crystalline beta zeolite with large intracrystalline mesopores has been facilely synthesized via the introduction of low-cost N-methyl-2- pyrrolidone (NMP) into common TEAOH-based zeolite synthesis mixtures, which exhibited remarkably higher catalytic activity contrast than conventional porous catalysts (ZSM-5, beta and Al-MCM-41) in acid-catalyzed reactions involving large molecules.
- Liu, Lijia,Wang, Hongbin,Wang, Runwei,Zeng, Shangjing,Ni, Ling,Zhang, Daliang,Zhu, Liangkui,Zou, Houbing,Qiu, Shilun,Zhang, Zongtao
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p. 39297 - 39300
(2014/11/08)
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- Effect of high-temperature calcination on the generation of Bronsted acid sites on WO3/Al2O3
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The acid properties of a series of alumina-supported tungsten oxide (WO3/Al2O3) catalysts with loadings of 5-50 wt% WO3 calcined at various temperatures were investigated by acid-catalyzed reactions (benzylation of anisole and isomerization of α-pinene) and FTIR spectroscopy. The relationships between acid properties, structures, and catalytic performances were evaluated. Both the catalytic activity and amount of Bronsted acid sites depend on the calcination temperature and WO3 loading. High-temperature calcination (1123 K) generated Bronsted acid properties, and 20 wt% WO 3/Al2O3 calcined at 1123 K exhibited the highest activity among the catalysts tested. The activities for the benzylation of anisole and α-pinene isomerization over WO3/Al 2O3 calcined at 1123 K were proportional to the Bronsted acidity, which indicates that these reactions occurred on the Bronsted acid sites. Tungsten oxide, which has distorted octahedral symmetry, was loaded as 2D monolayer domains below 20 wt%, and these domains covered most of the alumina surface at 20 wt%. If the WO3 loading was sufficient to form 2D tungsten oxide monolayer sheets (>20 wt%), some of the Bronsted acid sites on WO3/Al2O3 were obscured by monoclinic WO3 that has no Bronsted acid sites, which resulted in a decrease of the catalytic activity. This suggests that Bronsted acid sites are generated at the boundaries between tungsten oxide monolayer domains.
- Kitano, Tomoyuki,Hayashi, Tomohiro,Uesaka, Toshio,Shishido, Tetsuya,Teramura, Kentaro,Tanaka, Tsunehiro
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p. 2011 - 2020
(2014/08/05)
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- Superacidity in sulfated metal-organic framework-808
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Superacids, defined as acids with a Hammett acidity function H0 ≤ -12, are useful materials, but a need exists for new, designable solid state systems. Here, we report superacidity in a sulfated metal-organic framework (MOF) obtained by treating the microcrystalline form of MOF-808 [MOF-808-P: Zr6O5(OH)3- (BTC)2(HCOO)5(H2O)2, BTC = 1,3,5-benzenetricarboxylate] with aqueous sulfuric acid to generate its sulfated analogue, MOF-808-2.5SO4 [Zr6O5(OH)3(BTC)2- (SO4)2.5(H2O)2.5]. This material has a Hammett acidity function H0 ≤ -14.5 and is thus identified as a superacid, providing the first evidence for superacidity in MOFs. The superacidity is attributed to the presence of zirconiumbound sulfate groups structurally characterized using single-crystal X-ray diffraction analysis.
- Jiang, Juncong,Gándara, Felipe,Zhang, Yue-Biao,Na, Kyungsu,Yaghi, Omar M.,Klemperer, Walter G.
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supporting information
p. 12844 - 12847
(2015/12/26)
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- Metal-organic framework Co(D-cam)1/2(bdc)1/2(tmdpy) for improved enantioseparations on a chiral cyclodextrin stationary phase in gas chromatography
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Initial efforts to combine a chiral metal-organic framework (MOF), Co(D-Cam)1/2(bdc)1/2(tmdpy) (D-Cam=D-camphoric acid, bdc=1,4-benzenedicarboxylic acid, tmdpy=4,4′-trimethylenedipyridine), with peramylated β-cyclodextrins to investigate whether the use of a MOF can enhance enantioseparations on a cyclodextrin stationary phase are reported. Compared with columns of peramylated β-cyclodextrin incorporated in a MOF containing sodium chloride, the column of peramylated β-cyclodextrin+MOF shows excellent selectivity for the recognition of racemates, and higher resolutions are achieved on the peramylated β-cyclodextrin+MOF stationary phase. Experimental results indicate that the use of Co(D-Cam) 1/2(bdc)1/2(tmdpy) can improve enantioseparations on peramylated β-cyclodextrins. This is the first report that chiral MOFs can improve enantioseparations on a chiral stationary phase for chromatography. Copyright
- Liu, Hong,Xie, Sheng-Ming,Ai, Ping,Zhang, Jun-Hui,Zhang, Mei,Yuan, Li-Ming
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p. 1103 - 1108
(2014/11/07)
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- Fe(NO3)3-catalyzed monoterpene oxidation by hydrogen peroxide: An inexpensive and environmentally benign oxidative process
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Simple Fe(NO3)2·9H2O was demonstrated to be able to catalyze the oxidation of monoterpenes by hydrogen peroxide in methyl alcohol solution. Compared with the previous iron-catalyzed methods, the present procedure avoids the use of stabilizing ligands, additives, and corrosive peroxide organic oxidants. A novel, simple and highly efficient catalyst system was developed for oxidizing monoterpenes into a valuable derivates using hydrogen peroxide, an environmentally friendly oxidant. Graphical Abstract: Possible steps involved in the Fe(III)-catalyzed oxidation of β-pinene by hydrogen peroxide into myrtenol methyl ether in methyl alcohol[Figure not available: see fulltext.]
- Carari, Danieli Marcolan,Da Silva, Marcio Jose
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p. 615 - 622
(2014/04/03)
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- Synthesis of mesoporous Beta and Sn-Beta zeolites and their catalytic performances
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Mesoporous Beta zeolite has been successfully prepared through hydrothermal synthesis in the presence of cationic ammonium-modified chitosan as the meso-template. Through a subsequent solid-gas reaction between highly dealuminated mesoporous Beta zeolite and SnCl4 steam at an elevated temperature, mesoporous Sn-Beta has been facilely obtained. It was revealed that the addition of cationic chitosan induced the nanocrystal aggregation to particle sizes of ~300 nm, giving rise to the intercrystalline/interparticle mesoporosity. In the Sn-implanting procedure, Sn species were demonstrated to be doped into the framework of the resulting mesoporous Beta zeolite in a tetrahedral environment without structural collapse. Due to the micro/mesoporous structures, both mesoporous Beta and Sn-Beta exhibited superior performances in α-pinene isomerization, Baeyer-Villiger oxidation of 2-adamantanone by hydrogen peroxide and the isomerization of glucose in water, respectively. the Partner Organisations 2014.
- Jin, Junjiang,Ye, Xinxin,Li, Yongsheng,Wang, Yanqin,Li, Liang,Gu, Jinlou,Zhao, Wenru,Shi, Jianlin
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p. 8196 - 8204
(2014/06/09)
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- Alkylation of 2,4-dimethylphenol with (+)-α- and (-)-β-pinenes in the presence of aluminum xylenolate
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Alkylation of 2,4-dimethylphenol with (+)-α- and (-)-β-pinenes in the presence of aluminum 2,4-dimethylphenoxide generated in situ led to the formation of mixtures of products, from which optically active compounds were isolated. The structure of 2-bornyl
- Chukicheva,Krylova,Buravlev,Suponitskii,Kutchin
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p. 589 - 595
(2014/06/10)
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- TRANSITION METAL CATALYSTS FOR C-O HYDROGENOLYSIS AND HYDRODEOXYGENATION
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Phosphoranimide-metal catalysts and their role in C—O bond hydrogenolysis and hydrodeoxygenation (HDO) are disclosed. The catalysts comprise of first row transition metals such as nickel, cobalt and iron. The catalysts have a metal to anionic phosphoranimide ratio of 1:1 and catalyze C—O bond hydrogenolyses of a range of oxygen-containing organic compounds under lower temperature and pressure conditions than those commonly used in industrial hydrodeoxygenation.
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Paragraph 0190
(2014/07/08)
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- Ring-Opening Reactions of α- And β-Pinenes in Pressurized Hot Water in the Absence of Any Additive
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Reactions of α- and β-pinenes in pressurized hot water were examined in a batch reactor made of a SS316 1/2-in. tube at temperatures of 250-400 C, pressures of 4-30 MPa, and reaction times of 1-30 min in the absence of any additive under an argon atmosphere. The maximum yields of limonene from α-pinene were ca. 70% in 20 min at 300 C or 1 min at 400 C. Limonene was obtained from β-pinene in ca. 16% yield for 30 min at 300 C and 1 min at 400 C. Reversible production of myrcene in 14% yield and formation of unidentified C20 dimer fractions were noted for 1 min at 370 C from β-pinene. The conversion of α-pinene to limonene took place under anhydrous conditions, albeit at slightly lower yield of 65% compared to processes conducted in the presence of water, where increased limonene yield of 70% was observed for 1 min at 400 C. The conversion of β-pinene to limonene under anhydrous conditions was limited to 6.1% in contrast to 11.9% in the presence of water for 7 min at 370 C. In the presence of oxygen, p-cymene was formed in 23% and 24% yield at the expense of limonene from α- and β-pinenes, respectively, for 30 min at 400 C.
- Kawahara, Tomomi,Henmi, Yui,Onda, Natsu,Sato, Toshiyuki,Kawai-Nakamura, Akiko,Sue, Kiwamu,Iwamura, Hiizu,Hiaki, Toshihiko
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supporting information
p. 1485 - 1491
(2014/01/06)
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- Thermal behavior of pinan-2-ol and linalool
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Linalool is an important intermediate for syntheses of isoprenoid fragrance compounds and vitamins A and E. One process option for its production is the thermal gas-phase isomerization of cis- and trans-pinan-2-ol. Investigations of this reaction were performed in a flow-type apparatus in a temperature range from 350-600 °C and a residence time range of 0.6-0.8 s. Rearrangement of the bicyclic alcohol led to linalool, plinols arising from consecutive reactions of linalool and other side products. Effects of residence time, temperature, surface-to-volume-ratio, carrier gas, and the presence of additives on yield and selectivity were studied. Furthermore, the effects of such parameters on ene-cyclization of linalool affording plinols were investigated. Results indicate that manipulation of the reaction in order to affect selectivity is difficult due to the large free path length to other molecules in the gas phase. However, conditions have been identified allowing one to increase the selectivity and the yield of linalool throughout pyrolysis of pinan-2-ol.
- Leiner, Janne,Stolle, Achim,Ondruschka, Bernd,Netscher, Thomas,Bonrath, Werner
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p. 8358 - 8375
(2013/08/23)
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- Mechanistic insights into the rhenium-catalyzed alcohol-to-olefin dehydration reaction
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Rhenium-based complexes are powerful catalysts for the dehydration of various alcohols to the corresponding olefins. Here, we report on both experimental and theoretical (DFT) studies into the mechanism of the rhenium-catalyzed dehydration of alcohols to olefins in general, and the methyltrioxorhenium-catalyzed dehydration of 1-phenylethanol to styrene in particular. The experimental and theoretical studies are in good agreement, both showing the involvement of several proton transfers, and of a carbenium ion intermediate in the catalytic cycle. Ionic or concerted? Rhenium-based complexes are powerful catalysts for the dehydration of various alcohols to the corresponding olefins. Experimental and DFT studies into the mechanism of the rhenium-catalyzed dehydration of alcohols to olefins are reported. The experimental and theoretical studies are in good agreement, both showing the involvement of a carbenium ion intermediate in the catalytic cycle (see figure). Copyright
- Korstanje, Ties J.,Jastrzebski, Johann T. B. H.,Kleingebbink, Robertus J. M.
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p. 13224 - 13234
(2013/10/01)
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- A comparative study on the gas-phase and liquid-phase thermal isomerization reaction of α-pinene
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In this paper, a method of preparation of ocimene is investigated, which is obtained from isomerization reaction of α-pinene. Two kinds of experimental apparatus are established for the investigation of the thermal isomerization reaction of α-pinene. The behavior of thermal isomerization reaction of α-pinene is respectively discussed in the gas phase and in the liquid phase. Under gas phase conditions, the conversion of α-pinene is 80% and the selectivity of ocimene is 30%-33%. Under liquid phase conditions, the conversion of α-pinene is 60% and the selectivity of ocimene is 50%-54%. According to the kinetic-molecular theory of ideal gases, two kinds of reaction models are proposed to visualize the reaction process. In addition, the mechanism and kinetics of thermal isomerization reaction of α-pinene are respectively discussed. The conclusion is that the gas phase reaction temperature is calculated to be 390-450 °C and the liquid phase reaction temperature is calculated to be 450-550°C. From a bond dissociation energy point of view, results support the hypothesis that the reaction involves biradical intermediates. Copyright
- He, Jindong,Gong, Yan,Zhao, Wentao,Tang, Xiangyang,Qi, Xin
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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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