637-91-2Relevant academic research and scientific papers
Multistep electron transfer in oligopeptides: Direct observation of radical cation intermediates
Giese, Bernd,Napp, Matthias,Jacques, Olivier,Boudebous, Hassen,Taylor, Alexander M.,Wirz, Jakob
, p. 4073 - 4075 (2005)
Hopping holes: Oligopeptides with a photosensitive charge-injection system were synthesized and irradiated by a nanosecond laser. A multistep electron-transport process occurred which uses aromatic side chains as hole carriers (see scheme). The rates of t
Protein Modification at Tyrosine with Iminoxyl Radicals
Ishiyama, Takashi,Kanai, Motomu,Maruyama, Katsuya,Oisaki, Kounosuke,Sakai, Kentaro,Seki, Yohei,Togo, Takaya
supporting information, p. 19844 - 19855 (2021/11/30)
Post-translational modifications (PTMs) of proteins are a biological mechanism for reversibly controlling protein function. Synthetic protein modifications (SPMs) at specific canonical amino acids can mimic PTMs. However, reversible SPMs at hydrophobic amino acid residues in proteins are especially limited. Here, we report a tyrosine (Tyr)-selective SPM utilizing persistent iminoxyl radicals, which are readily generated from sterically hindered oximes via single-electron oxidation. The reactivity of iminoxyl radicals with Tyr was dependent on the steric and electronic demands of oximes; isopropyl methyl piperidinium oxime 1f formed stable adducts, whereas the reaction of tert-butyl methyl piperidinium oxime 1o was reversible. The difference in reversibility between 1f and 1o, differentiated only by one methyl group, is due to the stability of iminoxyl radicals, which is partly dictated by the bond dissociation energy of oxime O-H groups. The Tyr-selective modifications with 1f and 1o proceeded under physiologically relevant, mild conditions. Specifically, the stable Tyr-modification with 1f introduced functional small molecules, including an azobenzene photoswitch, to proteins. Moreover, masking critical Tyr residues by SPM with 1o, and subsequent deconjugation triggered by the treatment with a thiol, enabled on-demand control of protein functions. We applied this reversible Tyr modification with 1o to alter an enzymatic activity and the binding affinity of a monoclonal antibody with an antigen upon modification/deconjugation. The on-demand ON/OFF switch of protein functions through Tyr-selective and reversible covalent-bond formation will provide unique opportunities in biological research and therapeutics.
Synthesis method of high-purity 3-tert-butyl-5-(chloromethyl) isoxazole
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Paragraph 0060-0064, (2021/06/23)
The invention discloses a synthesis method of high-purity 3-tert-butyl-5-(chloromethyl) isoxazole, and the target product 3-tert-butyl-5-(chloromethyl) isoxazole is prepared; reaction conditions are mild, most reactions are carried out at room temperature and normal pressure, purification steps are simple, and the yield is high; and characterization results such as liquid chromatogram and nuclear magnetic spectrum show that the purity of the target product reaches 99.0% or above.
Potassium Poly(Heptazine Imide): Transition Metal-Free Solid-State Triplet Sensitizer in Cascade Energy Transfer and [3+2]-cycloadditions
Antonietti, Markus,Guldi, Dirk M.,Hussain, Tanveer,Karton, Amir,Markushyna, Yevheniia,Mazzanti, Stefano,Oschatz, Martin,Sánchez Vadillo, José Manuel,Savateev, Aleksandr,Strauss, Volker,Tarakina, Nadezda V.,Tyutyunnik, Alexander P.,Walczak, Ralf,ten Brummelhuis, Katharina
supporting information, p. 15061 - 15068 (2020/06/17)
Polymeric carbon nitride materials have been used in numerous light-to-energy conversion applications ranging from photocatalysis to optoelectronics. For a new application and modelling, we first refined the crystal structure of potassium poly(heptazine imide) (K-PHI)—a benchmark carbon nitride material in photocatalysis—by means of X-ray powder diffraction and transmission electron microscopy. Using the crystal structure of K-PHI, periodic DFT calculations were performed to calculate the density-of-states (DOS) and localize intra band states (IBS). IBS were found to be responsible for the enhanced K-PHI absorption in the near IR region, to serve as electron traps, and to be useful in energy transfer reactions. Once excited with visible light, carbon nitrides, in addition to the direct recombination, can also undergo singlet–triplet intersystem crossing. We utilized the K-PHI centered triplet excited states to trigger a cascade of energy transfer reactions and, in turn, to sensitize, for example, singlet oxygen (1O2) as a starting point to synthesis up to 25 different N-rich heterocycles.
Synthesis of novel N-pyridylpyrazole derivatives containing 1,2,4-oxadiazole moiety via 1,3-dipolar cycloaddition and their structures and biological activities
Zhang, Yan,Shang, Junfeng,Li, Huan,Liu, Hang,Song, Haibin,Wang, Baolei,Li, Zhengming
, p. 1276 - 1280 (2019/11/26)
A series of novel 1,2,4-oxadiazole-containing N-pyridylpyrazole derivatives 12a?h were efficiently synthesized with pivaldehyde, pyridylpyrazole carboxylic acid and arylamine as raw materials via 1,3-dipolar cycloaddition. Their structures were identified
SO2F2-Mediated one-pot cascade process for transformation of aldehydes (RCHO) to cyanamides (RNHCN)
Ding, Chengrong,Ge, Shuting,Wei, Junjie,Zhang, Guofu,Zhao, Yiyong
, p. 17288 - 17292 (2020/05/18)
A simple, mild and practical cascade process for the direct conversion of aldehydes to cyanamides was developed featuring a wide substrate scope and great functional group tolerability. This method allows for transformations of readily available, inexpensive, and abundant aldehydes to highly valuable cyanamides in a pot, atom, and step-economical manner with a green nitrogen source. This protocol will serve as a robust tool for the installation of the cyanamide moiety in various complicated molecules.
Synthesis of Tricyclic Isoxazoles via Sequential [3+2] Dipolar Cycloaddition and Palladium-Catalyzed Intramolecular Arylation Reactions
Guo, Dong-Cai,Zhang, Chao,Li, Fei,Zhang, Fenghua,Yu, Fang,He, Yu-Peng
, p. 1356 - 1370 (2017/03/11)
An efficient synthetic route to tricyclic isoxazoles via sequential copper-catalyzed 1,3-dipolar cycloaddition and palladium-catalyzed intramolecular arylation of isoxazoles is described. Based on these reactions, a convenient one-pot synthesis of the tri
Iron-catalyzed synthesis of benzoxazoles by oxidative coupling/cyclization of phenol derivatives with benzoyl aldehyde oximes
Gao, Sen,Gao, Liming,Meng, Hong,Luo, Meiming,Zeng, Xiaoming
supporting information, p. 9886 - 9889 (2017/09/11)
An iron-catalyzed oxidative coupling/cyclization reaction for the synthesis of benzoxazoles at room temperature is reported. This reaction was enabled by an inexpensive iron(iii) catalyst by treating readily available phenol derivatives with benzoyl aldehyde oximes. Mechanistic studies show that benzoyl aldehyde oxime is not only used as a substrate, but also serves as an ancillary ligand to support the iron salt in the promotion of the transformation.
TRIAZOLE-ISOXAZOLE COMPOUND AND MEDICAL USE THEREOF
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Paragraph 3423, (2016/06/06)
A compound represented by Formula [I]: or pharmaceutically acceptable salt thereof, wherein each symbol is as defined in the description.
Synthesis and evaluation of 4,5-dihydro-5-methylisoxazolin-5-carboxamide derivatives as VLA-4 antagonists
Soni, Ajay,Rehman, Abdul,Naik, Keshav,Dastidar, Sunanda,Alam,Ray, Abhijit,Chaira, Tridib,Shah, Vanya,Palle, Venkata P.,Cliffe, Ian A.,Sattigeri, Viswajanani J.
, p. 1482 - 1485 (2013/03/14)
A novel set of compounds containing a 4,5-dihydro-5-methylisoxazoline have been successfully designed as VLA-4 receptor antagonists. Compound (14p) had a high receptor binding affinity of 4 nM and also found to be metabolically stable in vitro.
