558-30-5Relevant articles and documents
Comparison of isoelectronic 8-HO-G and 8-NH2-G derivatives in redox processes
Kaloudis, Panagiotis,D'Angelantonio, Mila,Guerra, Maurizio,Spadafora, Marie,Cismas, Crina,Gimisis, Thanasis,Mulazzani, Quinto G.,Chatgilialoglu, Chryssostomos
, p. 15895 - 15902 (2009)
8-Oxo-7,8-dihydroguanine (8-oxo-G) is the major lesion of oxidatively generated DNA damage. Despite two decades of intense study, several fundamental properties remain to be defined. Its isoelectronic 8-aminoguanine (8-NH 2-G) has also received considerable attention from a biological point of view, although its chemistry involving redox processes remains to be discovered. We investigated the one-electron oxidation and one-electron reduction reactions of 8-oxo-G and 8-NH2-G derivatives. The reactions of hydrated electrons (eaq-) and azide radicals (N 3?) with both derivatives were studied by pulse radiolysis techniques, and the transient absorption spectra were assigned to specific tautomers computationally by means of time-dependent DFT (TD-B3LYP/6-311G**//B1B95/6-31+G**) calculations. The protonated electron adducts of 8-NH2-G and 8-oxo-G showed a substantial difference in their absorption spectra, the unpaired electron being mainly delocalized in the imidazolyl ring and in the six-membered ring, respectively. On the other hand, the deprotonated forms of one-electron oxidation of 8-NH2-G and 8-oxo-G showed quite similar spectral characteristics. In a parallel study, the one-electron reduction of 8-azidoguanine (8-N3-G) afforded the same transient of one-electron oxidation of 8-NH2-G, which represents another example of generation of one-electron oxidized guanine derivatives under reducing conditions. Moreover, the fate of transient species was investigated by radiolytic methods coupled with product studies and allowed self- and cross-termination rate constants associated with these reactions to be estimated.
Method for epoxidizing small-molecular olefin
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Paragraph 0180-0181; 0214-0215, (2021/06/06)
The invention relates to a micromolecular olefin epoxidation method, which is characterized by comprising the following steps: contacting micromolecular olefin, an organic peroxide and a titanium-silicon composite oxide under epoxidation reaction conditions of at least two reaction temperatures of A and B to obtain an alkylene oxide-containing product, wherein the A is 80-95 DEG C, the B is 100-120 DEG C, the titanium-silicon composite oxide is of an amorphous structure, is formed by aggregation of nano-particles and has mesopores in the range of 16-50 nm, the ratio of the volume of the mesopores to the total pore volume is larger than or equal to 80%, and the volume of the mesopores is larger than or equal to 0.5 cm/g. According to the method, the amorphous titanium-silicon-titanium-silicon composite oxide is taken as the catalyst, and at least two sections of conditions with different reaction temperatures are combined, so that compared with the prior art, the catalyst is stable in structure, low in cost, high in olefin epoxidation reaction activity and good in product selectivity.
PROCESS AND SYSTEM TO MAKE SUBSTITUTED LACTONES
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Paragraph 0052; 0055, (2021/02/05)
A process for oxidizing iso-butane with oxygen to produce t-butyl hydroperoxide and t-butyl alcohol; dehydrating at least a portion of the t-butyl alcohol to produce di-tert-butyl ether and isobutylene; epoxidizing at least a portion of the isobutylene with the t-butyl hydroperoxide to produce isobutylene oxide and t-butyl alcohol; and carbonylating at least a portion of the isobutylene oxide with carbon monoxide to produce pivalolactone.
Method for synthesizing isovaleraldehyde
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Paragraph 0033; 0035; 0038; 0040; 0043; 0045, (2020/12/05)
The invention provides a synthetic method of 3-methylcrotonaldehyde. The method comprises the following steps that epoxy isobutane is subjected to a hydroformylation reaction, hydroxy isovaleraldehydeis obtained, hydroxy isovaleraldehyde is subjected to an intramolecular dehydration reaction, and 3-methylcrotonaldehyde is obtained. The synthetic method of 3-methylcrotonaldehyde does not need harsh reaction conditions.
Rare earth metal compound, preparation method, composition, and method for catalyzing epoxidation of olefin
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Paragraph 0078-0079, (2020/07/24)
The invention relates to a rare earth metal compound and application thereof in catalyzing epoxidation of olefin. The rare earth metal compound disclosed by the invention has a structure as shown in aformula E. The invention also relates to a preparation method of the rare earth metal compound and a composition containing the rare earth metal compound. The method is characterized in that a rare earth metal compound is added into the reaction, so that the dosage of a molybdenum catalyst can be reduced. Olefin and organic peroxide react under the action of a catalyst to generate epoxide, the organic peroxide is converted into corresponding alcohol, and the conversion rate of the organic peroxide is larger than 99%. After the reaction is finished, the rare earth metal compound can be separated and recycled. The method has the advantages of simple process, high catalytic system activity, effective reduction of the use amount of the catalyst while guaranteeing the catalytic efficiency, andcost saving.
PROCESS FOR PREPARING 3-HYDROXY-3-METHYLBUTYRATE (HMB) AND SALTS THEREOF
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Page/Page column 8, (2020/10/31)
The present invention pertains to a process for preparing 3-hydroxy-3-methylbutyrate (HMB) or a salt thereof, the method comprising (a) reacting isobutylene oxide with cyanide in order to obtain 3- hydroxy-3-methylbutyronitrile, and (b) hydrolyzing the 3-hydroxy-3-methylbutyronitrile obtained in step (a) in order to obtain HMB, wherein hydrolysis step (b) is performed using either at least one nitrilase enzyme or, alternatively, using a combination of enzymes, said combination comprising at least one nitrile hydratase and at least one amidase.
SYSTEMS AND METHODS FOR REGIOSELECTIVE CARBONYLATION OF 2,2-DISUBSTITUTED EPOXIDES
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Paragraph 0146; 0151, (2020/06/05)
Provided are methods of carbonylating cyclic substrates to produce carbonyl ated cyclic products. The cyclic substrates may be 2, 2-di substituted epoxides and the cyclic products may be β,β-di substituted lactones. The method may be carried out by forming and pressurizing a reaction mixture of the cyclic substrate, a solvent, carbon monoxide, and a [LA+][CO(CO)4-] catalyst, where [LA+] is a Lewis acid capable of coordinating to the cyclic substrate. The method may proceed with a regioselectivity of 90:10 or greater. The resulting carbonylated cyclic products may be converted to ketone aldol products that retain the stereochemistry and enantiomeric ratio of the carbonyl ated cyclic products.
Synthesis and Structure of Tin and Germanium Complexes as Precursors Containing Alkoxyaminoalkoxide Ligands for Thin Film Transistors
Chung, Taek-Mo,Han, Seong Ho,Jeon, Dong Ju,Kim, Chang Gyoun,Lee, Ga Yeon,Lee, Ji Hun,Park, Bo Keun,Son, Seung Uk
, (2020/06/02)
This paper describes the preparation of four novel Sn and Ge complexes containing alkoxyaminoalkoxide type ligands {L1H = 1-[methoxy(methyl)amino]-2-methylpropan-2-ol; L2H = 1-[methoxy(methyl)amino]-2-methylbutan-2-ol} for potential use as precursors for thin film transistors. All compounds were prepared at room temperature by stirring a solution containing Sn(btsa)2 [btsa = bis(trimethylsilyl)amide] or Ge(btsa)2 with two equivalents of L1H or L2H to form Sn(L1)2 (1), Sn(L2)2 (2), Ge(L1)2 (3) and Ge(L2)2 (4). All of the complexes were characterized by NMR and FTIR spectroscopy as well as elemental and thermogravimetric analyses. When the more symmetric and compact ligand L1H was applied, solid products 1 and 3 were generated and their structures were studied using X-ray diffraction. Applying the strategy of ligand design at the molecular level, the symmetric ligand was changed to an asymmetric one, replacing one of the two neighboring methyl groups of the amino alcohol group with an ethyl group, and forming liquid complexes 2 and 4 for both metals.
Diastereoselective Desymmetrization of p-Quinamines through Regioselective Ring Opening of Epoxides and Aziridines
Jadhav, Sandip B.,Chegondi, Rambabu
supporting information, p. 10115 - 10119 (2019/12/24)
A highly diastereoselective desymmetrization of p-quinamines via regioselective ring opening of epoxides and aziridines under mild conditions has been developed. A chairlike six-membered transition state with minimized 1,3-diaxial interactions explains the relative stereoselectivity of the cyclization reaction. This transition-metal free [3 + 3] annulation reaction provides rapid access to fused bicyclic morpholines and piperazines with a tetrasubstituted carbon center in high yields. In addition, it also allows the synthesis of enantioenriched products by using easily accessible chiral nonracemic epoxides and aziridines.
Mechanistic insights into light-driven graphene-induced peroxide decomposition: Radical generation and disproportionation
Chu, Ya-Lan,Chen, Yen-An,Li, Wei-Chin,Chu, Jean-Ho,Chen, Chun-Hu,Chiang, Chao-Ming
supporting information, p. 9291 - 9294 (2016/07/25)
Interaction between adsorbed t-butyl peroxybenzoate and photoexcited graphene rendered trapped phenyl and t-butoxy radicals. Post-irradiation thermal desorption showed benzene, t-butanol, and isobutylene oxide as the end products. The required hydrogen at
