4043-87-2Relevant academic research and scientific papers
An in situ FT-IR study on photocatalytic reaction at semiconductor-aqueous solution interface - Mechanism of photocatalytic N-cyclization of (S)-lysine
Ohtani, Bunsho,Yako, Takayuki,Samukawa, Yoriaki,Nishimoto, Sei-Ichi,Kanamura, Kiyoshi
, p. 91 - 92 (1997)
Photoinduced reaction occurring at an aqueous solution-semiconductor interface was analyzed in situ by reflection FT-IR spectroscopy. The photoinduced reflection spectral change, ΔR (= (R-R0)/R0), was recorded by using an IR cell consisting of a semiconductor (TiCO2 or CdS) thin film electrode, a thin layer of aqueous (S)-lysine solution, and a calcium fluoride window. Structure of adsorbed substrate and mechanism of photoinduced reaction were discussed.
Photocatalytic Synthesis of Pipecolic Acid from Lysine on TiO2: Effects of the Structure of Catalysts and Adsorbed Species on Chiral Selectivity
Zhai, Yuxin,Chuang, Steven S. C.
, p. 1636 - 1643 (2018)
A one-step photocatalytic synthesis of l-pipecolic acid (l-PCA) from l-lysine (l-Lys) has been investigated by in situ infrared (IR), circular dichroism, and 1H NMR spectroscopy. Chiral selectivity toward l-Lys was found to be governed by the structure of adsorbed l-Lys and the structure of TiO2. Both anatase and rutile were not able to catalyze the reaction in a solvent-free environment. In situ IR studies revealed that l-Lys adsorbed on these TiO2 in a dicationic form of which the positive -NH3+ functional groups are not able to interact with photogenerated holes. Interestingly, P-25 TiO2, which contains 80 wt % anatase and 20 wt % rutile, adsorbs l-Lys in a zwitterionic form, allowing its hydrogen in the α-amino group to be abstracted by the photogenerated hole, producing racemic PCA. The addition of H2O as a solvent allowed l-Lys to be adsorbed on P-25 in an anionic form, producing l-PCA as a major product. This study demonstrates that the reaction environment has a direct impact on the structure of adsorbed species that controls the selectivity of a chiral synthesis.
Recyclable Rh-PVP nanoparticles catalyzed hydrogenation of benzoic acid derivatives and quinolines under solvent-free conditions
Chaudhari, Chandan,Imatome, Hirotaka,Nishida, Yoshihide,Sato, Katsutoshi,Nagaoka, Katsutoshi
, p. 55 - 60 (2019/05/10)
Various transition metal nanoparticles, prepared by microwave-assisted alcohol reduction method were examined for hydrogenation of benzoic acid to cyclohexanecarboxylic acid under solvent-free conditions. Rh metal was the most effective catalyst over other metal catalyst. The catalyst showed moderate to high yield for the hydrogenation of substituted benzoic acid and substituted quinolines. Rh-PVP was recycled four times with a minor loss in catalytic activity.
Encapsulation of Nonprecious Metal into Ordered Mesoporous N-Doped Carbon for Efficient Quinoline Transfer Hydrogenation with Formic Acid
Li, Guoqiang,Yang, Huanhuan,Zhang, Haifu,Qi, Zhiyuan,Chen, Minda,Hu, Wei,Tian, Lihong,Nie, Renfeng,Huang, Wenyu
, p. 8396 - 8405 (2018/08/17)
Ordered mesoporous N-doped carbon (OMNC) encapsulating Co nanoparticles (NPs) have been prepared under direct polymerization between [Co(NH2CH2CH2NH2)2]Cl2 and carbon tetrachloride through a hard template method. The catalysts (Co@OMNC) are pyrolyzed at various temperatures and characterized by elemental analysis, Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). In the quinoline transfer hydrogenation with formic acid (FA) as the hydrogen source under a base-free condition, the encapsulated Co NPs are physically isolated from the acidic reaction solution, which prevents them from poisoning or leaching. The rich mesopores and N dopants afford enhanced adsorption of quinoline. Co@OMNC-700 (pyrolyzed at 700 °C) gives the best activity (98.8% conversion) as well as >99% 1,2,3,4-tetrahydroquinoline (THQ) selectivity at 140 °C for 4 h, exhibiting significantly improved performance compared to using H2 as the hydrogenation source. Moreover, Co@OMNC-700 is stable for recycling and exhibits high efficiency in FA dehydrogenation. Co@OMNC-700 is also a high-performance catalyst in the transfer hydrogenation of various unsaturated hydrocarbons. On the contrary, without the protection of OMNC, the exposed Co NPs in a control catalyst, Co/OMNC-700, lead to obvious Co leaching and low efficiency for the transfer hydrogenation of quinoline with FA.
Focal adhesion kinase inhibitor and use
-
Paragraph 0404; 0406; 0408, (2019/01/08)
The invention belongs to the field of medicines, relates to a focal adhesion kinase inhibitor and use, in particular relates to a novel focal adhesion kinase inhibitor compound, or stereoisomers, geometric isomers, tautomers, oxynitrides, hydrates, solvates, metabolites, pharmaceutically acceptable salts or prodrugs thereof, further relates to the use of the compound and pharmaceutical compositions as medicines, in particular the use of the compound and pharmaceutical compositions in manufacture of medicines for treatment or prevention of cancer, pulmonary hypertension, and pathological angiogenesis-related diseases.
PROCESS FOR PRODUCING SOLID AMINO ACID
-
Paragraph 0055, (2014/12/09)
The problem to be solved by the present invention is to ea lily and efficiently produce an amino acid having 2 to 7 carbon atoms as a high-purity solid without complicated operation, which is useful as a synthetic intermediate for medicines or agrochemicals. The present invention is characterized in comprising a step of precipitating solid amino acid with high purity. In the present invention, the by-produced salt composed of the sulfonic acid and the amine was removed to the mother liquor by reacting an amine with a sulfonic acid salt of amino acid in an aprotic polar solvent, or by reacting a sulfonic acid with an amine salt of amino acid in an aprotic polar solvent. The sulfonic acid salt of amino acid, for example, may be produced by reacting a N-(tert-butoxycarbonyl) amino acid with a sulfonic acid, or by reacting an amino acid tert-butyl ester with a sulfonic acid.
Synthetic cascades are enabled by combining biocatalysts with artificial metalloenzymes
Koehler,Wilson,Duerrenberger,Ghislieri,Churakova,Quinto,Knoerr,Haeussinger,Hollmann,Turner,Ward
, p. 93 - 99 (2013/08/24)
Enzymatic catalysis and homogeneous catalysis offer complementary means to address synthetic challenges, both in chemistry and in biology. Despite its attractiveness, the implementation of concurrent cascade reactions that combine an organometallic catalyst with an enzyme has proven challenging because of the mutual inactivation of both catalysts. To address this, we show that incorporation of a d 6 -piano stool complex within a host protein affords an artificial transfer hydrogenase (ATHase) that is fully compatible with and complementary to natural enzymes, thus enabling efficient concurrent tandem catalysis. To illustrate the generality of the approach, the ATHase was combined with various NADH-, FAD- and haem-dependent enzymes, resulting in orthogonal redox cascades. Up to three enzymes were integrated in the cascade and combined with the ATHase with a view to achieving (i) a double stereoselective amine deracemization, (ii) a horseradish peroxidase-coupled readout of the transfer hydrogenase activity towards its genetic optimization, (iii) the formation of L-pipecolic acid from L-lysine and (iv) regeneration of NADH to promote a monooxygenase-catalysed oxyfunctionalization reaction.
A concise and diastereoselective synthesis of piperidine and indolizidine alkaloids via aza-Prins cyclization
Reddy, Basi V. Subba,Chaya, Dudhmal N.,Yadav, Jhillu S.,Gree, Rene
experimental part, p. 297 - 303 (2012/03/26)
The synthesis of 2-substituted and 2,4-disubstituted piperidine alkaloids such as (±)-coniine, (±)-hydroxypipecolic acid, (±)-pipecolic acid, (±)-coniceine, and (±)-4-hydroxy-2- hydroxy-methyl piperidine have been accomplished in a highly diastereo-selective manner by employing aza-Prins cyclization as a key step to construct the piperidine core of these alkaloids. Georg Thieme Verlag Stuttgart · New York.
Continuous flow hydrogenation of functionalized pyridines
Irfan, Muhammed,Petricci, Elena,Glasnov, Toma N.,Taddei, Maurizio,Kappe, C. Oliver
experimental part, p. 1327 - 1334 (2009/07/19)
The heterogeneous hydrogenation of substituted pyridines has been accomplished by employing a continuous flow hydrogenation device that incorporates in situ hydrogen generation by electrolysis of H20 and pre-packed catalyst cartridges. In general, the hydrogenation reactions proceeded smoothly regardless of the supported precious metal catalyst (Pd/C, Pt/C, or Rh/C). By using 30-80 bar of hydrogen pressure at 60-80 °C full conversion was typically achieved in all cases at a flow rate of 0.5 mL min -1, providing the corresponding piperidines in high yields. For disubstituted pyr idines, variations in stereoselectivity were observed depending on both the metal catalyst and the temperature/ pressure of the hydrogenation reaction. For ethyl nicotinate the selectivity between partial and full hydrogenation could be tuned depending on the hydrogen pressure, solvent, and the choice of supported metal catalyst. Changing the hydrogen source from H20 to D2C) allowed the preparation of de-uteriated derivatives. Wiley-VCH Verlag GmbH & Co. KGaA.
CATALYTIC DEAMINATION FOR CARPROLACTAM PRODUCTION
-
Page/Page column 17, 19, (2008/12/08)
Catalytic processes for preparing caprolactam, pipecolinic acid, and their derivatives, from lysine or alpha-amino-epsilon-caprolactam starting materials, and products produced thereby. A process for preparing caprolactam or a derivative thereof, the process comprising contacting a reactant comprising lysine or alpha aminocaprolactam with a catalyst and a gas comprising hydrogen gas, in the presence of a solvent. The catalyst may be provided on a support material, such as a transition metal.
