130249-17-1Relevant academic research and scientific papers
Asymmetric epoxidation with H2O2 by manipulating the electronic properties of non-heme iron catalysts
Cusso, Olaf,Garcia-Bosch, Isaac,Ribas, Xavi,Lloret-Fillol, Julio,Costas, Miquel
, p. 14871 - 14878 (2013)
A non-heme iron complex that catalyzes highly enantioselective epoxidation of olefins with H2O2 is described. Improvement of enantiomeric excesses is attained by the use of catalytic amounts of carboxylic acid additives. Electronic effects imposed by the ligand on the iron center are shown to synergistically cooperate with catalytic amounts of carboxylic acids in promoting efficient O-O cleavage and creating highly chemo-and enantioselective epoxidizing species which provide a broad range of epoxides in synthetically valuable yields and short reaction times.
NMR studies of three types of highly coordinated organotin hydrides: Chemo-, regio-, and stereoselective reduction of 2,3-epoxy ketones
Kawakami, Takayo,Shibata, Ikuya,Baba, Akio
, p. 82 - 87 (1996)
Three types of highly coordinated organotin hydrides, Bu2SnIH-Lewis base (Lewis bases; HMPA or tripiperidinophosphine oxide) (type A), Bu2SnFH-HMPA (type B), and Bu3SnH-Bu4NX (X = F, CN) (type C), were characterized as nucleophilic, chelation, and nonchelation types of reductants, respectively, in the reaction with 2,3-epoxy ketones 1. These reagents, which promoted a reduction of the epoxy ring and syn-selective and anti-selective carbonyl reduction, respectively, were spectroscopically confirmed with 1H, 13C, 19F, and 119Sn NMR and FT-IR. Furthermore, the correlations between their structures and selective reducing abilities were discussed.
Epoxidation of alkenes and their derivatives over Ti-YNU-1
Shen, Xiaohua,Fan, Weibin,He, Yue,Wu, Peng,Wang, Jianguo,Tatsumi, Takashi
, p. 37 - 45 (2011)
The catalytic properties of Ti-YNU-1 for the epoxidation of various alkenes and their derivatives have been investigated in detail, and further were made a comparison with those of Ti-Beta. The much higher efficiency of Ti-YNU-1 than Ti-Beta was observed in catalyzing the epoxidation of alkenes and their electron-rich analogues. Although it was less active in the epoxidation of α,β-unsaturated ketones, it showed much higher stability. In contrast, Ti leaching from the framework sites occurred to Ti-Beta, and the leaching degree increased with the carbon number of ketones. It was also shown that the catalytic conditions, including the Ti content in samples, H 2O2/substrate ratio, reaction temperature and time, acid washing and catalyst amount, significantly influenced the activity, selectivity and H2O2 efficiency. Co-oxidation of different alkenes led to the activity and epoxide selectivity being different from those obtained in the oxidation of single olefin as a result of the differences in adsorption properties of substrates over various titanosilicates, which affected the diffusion of substrate molecules and accounted for the unique shape-selectivity of Ti-YNU-1.
Metalated epoxides as carbenoids. Stereospecific synthesis of functionalized spiro cyclopropanes via highly strained tricyclic intermediates
Agami, Claude,Dechoux, Luc,Doris, Eric,Mioskowski, Charles
, p. 4071 - 4074 (1997)
Intramolecular cyclopropanation reaction of β,γ-unsaturated epoxides yields highly strained tricyclo[4,1,0,01,5]heptane compounds whose hydrolysis affords α-keto spiro cyclopropanes. Both steps of this one-pot reaction are stereospecific.
Photoresist acid sensitive resin monomer with good alkali solubility as well as synthesis method and application thereof
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Paragraph 0037; 0044, (2021/10/13)
The invention discloses a photoresist acid sensitive resin monomer with good alkali solubility and a synthesis method and application thereof, and relates to the field of photoresist resin monomers. In-flight R1 Methyl or hydrogen, R2/sub
Tandem Lewis acid catalysis for the conversion of alkenes to 1,2-diols in the confined space of bifunctional TiSn-Beta zeolite
Lei, Qifeng,Wang, Chang,Dai, Weili,Wu, Guangjun,Guan, Naijia,Hunger, Michael,Li, Landong
, p. 1176 - 1184 (2021/02/16)
The generation of multifunctional isolated active sites in zeolite supports is an attractive method for integrating multistep sequential reactions into a single-pass tandem catalytic reaction. In this study, bifunctional TiSn-Beta zeolite was prepared by a simple and scalable post-synthesis approach, and it was utilized as an efficient heterogeneous catalyst for the tandem conversion of alkenes to 1,2-diols. The isolated Ti and Sn Lewis acid sites within the TiSn-Beta zeolite can efficiently integrate alkene epoxidation and epoxide hydration in tandem in a zeolite microreactor to achieve one-step conversion of alkenes to 1,2-diols with a high selectivity of >90%. Zeolite confinement effects result in high tandem rates of alkene epoxidation and epoxide hydration as well as high selectivity toward the desired product. Further, the novel method demonstrated herein can be employed to other tandem catalytic reactions for sustainable chemical production.
Pyrenediones as versatile photocatalysts for oxygenation reactions with: In situ generation of hydrogen peroxide under visible light
Zhang, Yuannian,Yang, Xin,Tang, Haidi,Liang, Dong,Wu, Jie,Huang, Dejian
supporting information, p. 22 - 27 (2020/01/13)
Pyrenediones (PYDs) are efficient photocatalysts for three oxygenation reactions: Epoxidation of electron deficient olefins, oxidative hydroxylation of organoborons, and oxidation of sulfides via in situ generation of H2O2 under visible light irradiation, using oxygen as a terminal oxidant and IPA as a solvent and a hydrogen donor.
Discovery of Novel 1-Cyclopentenyl-3-phenylureas as Selective, Brain Penetrant, and Orally Bioavailable CXCR2 Antagonists
Lu, Hongfu,Yang, Ting,Xu, Zhongmiao,Lin, Xichen,Ding, Qian,Zhang, Yueting,Cai, Xin,Dong, Kelly,Gong, Sophie,Zhang, Wei,Patel, Metul,Copley, Royston C. B.,Xiang, Jianing,Guan, Xiaoming,Wren, Paul,Ren, Feng
supporting information, p. 2518 - 2532 (2018/03/26)
CXCR2 has emerged as a therapeutic target for not only peripheral inflammatory diseases but also neurological abnormalities in the central nervous system (CNS). Herein, we describe the discovery of a novel 1-cyclopentenyl-3-phenylurea series as potent and CNS penetrant CXCR2 antagonists. Extensive SAR studies, wherein molecules' property forecast index (PFI) was carefully optimized for overall balanced developability profiles, led to the discovery of the advanced lead compound 68 with a desirable PFI. Compound 68 demonstrated good in vitro pharmacology with excellent selectivity over CXCR1 and other chemokine receptors. Rat and dog pharmacokinetics (PK) revealed good oral bioavailability, high oral exposure, and desirable elimination half-life of the compound in both species. In addition, the compound demonstrated dose-dependent efficacy in the in vivo pharmacology neutrophil infiltration "air pouch" model in rodents after oral administration. Further, compound 68 is a CNS penetrant molecule with high unbound fraction in brain tissue.
1 -(CYCLOPENT-2-EN-1 -YL)-3-(2-HYDROXY-3-(ARYLSULFONYL)PHENYL)UREA DERIVATIVES AS CXCR2 INHIBITORS
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Page/Page column 39, (2015/12/18)
The invention relates to 1-(3-sulfonylphenyl)-3-(cyclopent-2-en-1-yl)urea derivatives, and their use in treating or preventing diseases and conditions mediated by the CXCR2 receptor. In addition, the invention relates to compositions containing the derivatives and processes for their preparation.
A procedure for the preparation of Ti-Beta zeolites for catalytic epoxidation with hydrogen peroxide
Tang, Bo,Dai, Weili,Sun, Xiaoming,Guan, Naijia,Li, Landong,Hunger, Michael
, p. 2281 - 2291 (2014/04/17)
Ti-Beta zeolite has been successfully prepared via a reproducible and scalable two-step post-synthesis strategy, which consists of creating vacant T sites with associated silanol groups by dealumination of H-Beta and subsequent dry impregnation of the resulting Si-Beta with titanocene dichloride. The mechanism of Ti incorporation into the framework of Beta is investigated by diffuse reflectance infrared Fourier transform (DRIFT) and multinuclear solid-state nuclear magnetic resonance (SSNMR) spectroscopy. Characterization results obtained from diffuse reflectance ultraviolet-visible (UV-vis) and X-ray photoelectron spectroscopy (XPS) reveal that the majority of incorporated Ti species exist in the form of isolated tetrahedrally coordinated Ti(iv) in the zeolite framework while a minority exists in the form of isolated octahedrally coordinated Ti(vi) at framework or extra-framework positions. The obtained Ti-Beta zeolites are highly active and selective catalysts for the epoxidation of unsaturated ketones, e.g. 2-cyclohexen-1-one, with hydrogen peroxide as an oxidant. A quasilinear correlation between the epoxidation rate and the number of framework Ti(iv) species could be drawn evidencing that these Ti(iv) species are responsible for the epoxidation activity of the Ti-Beta zeolites under study. The impact of preparation parameters and reaction conditions on the catalytic performances of the Ti-Beta zeolites in the epoxidation of unsaturated organic compounds with hydrogen peroxide is discussed in detail. the Partner Organisations 2014.
