13326-06-2Relevant articles and documents
Potent Odorants of Characteristic Floral/Sweet Odor in Chinese Chrysanthemum Flower Tea Infusion
Kaneko, Shu,Chen, Jingxiu,Wu, Jieming,Suzuki, Yuto,Ma, Lin,Kumazawa, Kenji
, p. 10058 - 10063 (2017)
An investigation using the aroma extract dilution analysis (AEDA) technique applied to the aroma concentrates prepared from the tea infusions of two different types of Chinese chrysanthemum flowers (flower buds, blooming flowers) revealed that 29 aroma peaks were detected in the aroma concentrates, and 17 compounds were newly identified or tentatively identified in the chrysanthemum flower tea. AEDA also revealed that the aroma peaks having high flavor dilution factors mainly consisted of a floral/sweet note in addition to metallic and phenol-like/spicy notes. Among them, four aroma peaks having a floral/sweet were identified as verbenone, ethyl 3-phenylpropanoate, propyl 3-phenylpropanoate, and ethyl cinnamate, and a semiquantitative analysis revealed that the flower buds were rich in these compounds. Furthermore, a chiral analysis revealed that (-)-verbenone existed in both flowers at a 3 times higher concentration than (+)-verbenone. Additionally, because the detection threshold of (-)-verbenone was lower than that of the (+)-verbenone, it is concluded that the (-)-isomer was a main contributor of the aroma peak of verbenone in the chrysanthemum flower tea.
Esterification or Thioesterification of Carboxylic Acids with Alcohols or Thiols Using Amphipathic Monolith-SO3H Resin
Ichihara, Shuta,Ishida, Moeka,Ito, Ryo,Kato, Ayumu,Monguchi, Yasunari,Nakamura, Shinji,Park, Kwihwan,Sajiki, Hironao,Takada, Hitoshi,Wakayama, Fumika,Yamada, Tsuyoshi,Yamada, Yutaro
, p. 2702 - 2710 (2022/01/19)
We have developed a method for the esterification of carboxylic acids with alcohols using amphipathic, monolithic-resin bearing sulfonic acid moieties as cation exchange functions (monolith-SO3H). Monolith-SO3H efficiently catalyzed the esterification of aromatic and aliphatic carboxylic acids with various primary and secondary alcohols (1.55.0 equiv) in toluene at 6080 °C without the need to remove water generated during the reaction. The amphipathic property of monolith-SO3H facilitates dehydration due to its capacity for water absorption. This reaction was also applicable to thioesterification, wherein the corresponding thioesters were obtained in excellent yield using only 2.0 equiv of thiol in toluene, although heating at 120 °C was required. Moreover, monolith-SO3H was separable from the reaction mixtures by simple filtration and reused for at least five runs without decreasing the catalytic activity.
Method for selective reduction α, β - unsaturated carbonyl compound carbon-carbon double bond (by machine translation)
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Paragraph 0075-0078, (2020/06/17)
The invention discloses a method for selectively reducing carbon-carbon double bonds in α and β - unsaturated carbonyl compounds, which comprises the following steps of adding α, β - unsaturated carbonyl compounds shown in formula (I) in an electrolysis system and reducing α and β - unsaturated carbonyl compounds with carbonyl-conjugated carbon-carbon double bonds through an electrochemical cathodic reduction reaction. Compared with the reported method, the method disclosed by the invention does not use a metal catalyst and an external oxidant; and the reaction raw material and the electrolyte are low in price, nontoxic and tasteless, simple and convenient in post-treatment. (by machine translation)
Hydrogenation of Ketones and Esters Catalyzed by Pd/C?SiO2
Akchurin,Baibulatov,Dokichev
, p. 195 - 198 (2018/03/26)
Hydrogenation of unsaturated ketones and esters with molecular hydrogen on the 5%Pd/C?SiO2 heterogeneous catalyst has been studied. The reaction direction and yield are determined by the starting compounds structure. Hydrogenation of unsaturated ketones containing phenyl group at the double carbon–carbon atom is accompanied by the reduction of the ketone group into the alcohol one. Hydrogenation of unsaturated esters is accompanied by transesterification.
Esterification, transesterification and hydrogenation reactions of polyunsaturated compounds catalyzed by a recyclable polymer supported palladium catalyst
Dell'Anna, Maria Michela,Capodiferro, Vito Filippo,Mali, Matilda,Mastrorilli, Piero
, p. 106 - 114 (2016/07/06)
Aliphatic and aromatic carboxylic acids were converted into their corresponding esters using a polymer supported palladium(II) β-ketoesterate complex under hydrogen atmosphere in the presence of catalytic bromobenzene in alcohols. This method was also applicable to the transesterification of esters. Good to excellent yields were obtained for different aliphatic or aromatic starting materials. The esterification (or transesterification) was promoted by the in situ generation of HBr from bromobenzene, which provided a mild acidic reaction environment. Pd(II) centers were converted into polymer stabilized metal nanoparticles (the true active species) under reaction conditions. The palladium catalyst exhibited a remarkable activity and was reusable for eight consecutive cycles. The present system was also tested for the preparation of partially hydrogenated fatty acid methyl esters, starting from a mixture composed by highly polyunsaturated esters and free carboxylic acids, taken as a model acidic feedstock for biodiesel upgrading.
Unique Chemoselective Hydrogenation using a Palladium Catalyst Immobilized on Ceramic
Monguchi, Yasunari,Marumoto, Takahisa,Ichikawa, Tomohiro,Miyake, Yutaka,Nagae, Yoshiyuki,Yoshida, Michiyuki,Oumi, Yasunori,Sawama, Yoshinari,Sajiki, Hironao
, p. 2155 - 2160 (2015/11/24)
A heterogeneous palladium catalyst supported on a ceramic (5 % Pd/ceramic) was developed. The catalyst exhibited a specific chemoselectivity for hydrogenation that has never been achieved by other palladium-catalyzed methods. Either aliphatic or aromatic N-Cbz groups could be deprotected to the corresponding free-amines, while the hydrogenolysis of benzyl esters and ethers did not proceed. Furthermore, aryl chlorides and epoxides were tolerant under the Pd/ceramic-catalyzed hydrogenation conditions. 5 % Pd/ceramic could be reused without any loss of catalyst activity, as no palladium leaching was detected in the reaction media.
Ambulation of Incipient Proton during Gas-Phase Dissociation of Protonated Alkyl Dihydrocinnamates
Xu, Sihang,Zhang, Yong,Errabelli, Ramu,Attygalle, Athula B.
, p. 9468 - 9479 (2015/10/12)
Upon activation in the gas phase, protonated alkyl dihydrocinnamates undergo an alcohol loss. However, the mechanism followed is not a simple removal of an alkanol molecule after a protonation on the alkoxy group. The mass spectrum of the m/z 166 ion for deuteron-charged methyl dihydrocinnamate showed two peaks of 1:5 intensity ratio at m/z 133 and 134 to confirm that the incipient proton is mobile. The proton initially attached to the carbonyl group migrates to the ring and randomizes before a subsequent transfer of one of the ring protons to the alkoxy group for the concomitant alcohol elimination. Moreover, protonated methyl dihydrocinnamate undergoes more than one H/D exchange. The spectra recorded from m/z 167 and 168 ions obtained for di- and tri-deuterio isotopologues showed peak pairs at m/z 134, 135 and 135, 136, at 1:2 and 1:1 intensity ratios, respectively, confirming the benzenium ion intermediate achieves complete randomization before the proton transfer. Additionally, protonated higher esters of alkyl dihydrocinnamates undergo a cleavage of the O-CH2 bond to form an ion/neutral complex, which, upon activation, dissociates generating a carbenium ion and dihydrocinnamic acid, or rearranges to generate protonated dihydrocinnamic acid and an alkene by a nonspecific proton transfer.
Novel ruthenium-catalyst for hydroesterification of olefins with formates
Profir, Irina,Beller, Matthias,Fleischer, Ivana
supporting information, p. 6972 - 6976 (2014/10/15)
An alternative ruthenium-based catalyst for the hydroesterification of olefins with formates is reported. The good activity of our system is ensured by the use of a bidentate P,N-ligand and ruthenium dodecacarbonyl. A range of formates can be used for selective alkoxycarbonylation of aromatic olefins. In addition, the synthesis of selected aliphatic esters is realized. The proposed active ruthenium complex has been isolated and characterized. This journal is the Partner Organisations 2014.
Synthesis of sulfonic acid containing ionic-liquid-based periodic mesoporous organosilica and study of its catalytic performance in the esterification of carboxylic acids
Elhamifar, Dawood,Karimi, Babak,Moradi, Abbas,Rastegar, Javad
, p. 1147 - 1152 (2014/10/16)
A new sulfonic acid containing ionic-liquid-based periodic mesoporous organosilica (PMO-IL-SO3H) material was prepared and its catalytic application was investigated in the esterification of carboxylic acids with alcohols. The PMO-IL-SO3H nanocatalyst was first characterized with diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and nitrogen sorption analysis. Then, the catalytic performance of this material was studied in the esterification of carboxylic acids with short- and long-chain aliphatic alcohols, cyclic alcohols, and benzylic alcohols under solvent-free conditions. The results showed that the catalyst has superior activity for the conversion of several alcohols to afford the corresponding ester products in excellent yields and high purity. Moreover, the catalyst could be recovered and reused several times without a significant decrease in activity and product selectivity. Copyright
Combined catalytic system of scandium triflate and boronic ester for amide bond cleavage
Kita, Yusuke,Nishii, Yuji,Onoue, Akihiro,Mashima, Kazushi
supporting information, p. 3391 - 3395 (2013/12/04)
We have found that the combination of scandium with boronic ester enables the cleavage of amide bonds. Primary amides were converted to the corresponding esters in the presence of catalytic amounts of scandium triflate and boronic ester under mild and neutral conditions. This unique catalytic system can be applied to the deprotection of acetylaniline derivatives. In addition, control NMR experiments were carried out to examine the effect of the boronic esters. Copyright
