- Metal-Organic Capsules with NADH Mimics as Switchable Selectivity Regulators for Photocatalytic Transfer Hydrogenation
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Switchable selective hydrogenation among the groups in multifunctional compounds is challenging because selective hydrogenation is of great interest in the synthesis of fine chemicals and pharmaceuticals as a result of the importance of key intermediates. Herein, we report a new approach to highly selectively (>99%) reducing C=X (X = O, N) over the thermodynamically more favorable nitro groups locating the substrate in a metal-organic capsule containing NADH active sites. Within the capsule, the NADH active sites reduce the double bonds via a typical 2e- hydride transfer hydrogenation, and the formed excited-state NAD+ mimics oxidize the reductant via two consecutive 1e- processes to regenerate the NADH active sites under illumination. Outside the capsule, nitro groups are highly selectively reduced through a typical 1e- hydrogenation. By combining photoinduced 1e- transfer regeneration outside the cage, both 1e- and 2e- hydrogenation can be switched controllably by varying the concentrations of the substrates and the redox potential of electron donors. This promising alternative approach, which could proceed under mild reaction conditions and use easy-to-handle hydrogen donors with enhanced high selectivity toward different groups, is based on the localization and differentiation of the 2e- and 1e- hydrogenation pathways inside and outside the capsules, provides a deep comprehension of photocatalytic microscopic reaction processes, and will allow the design and optimization of catalysts. We demonstrate the advantage of this method over typical hydrogenation that involves specific activation via well-modified catalytic sites and present results on the high, well-controlled, and switchable selectivity for the hydrogenation of a variety of substituted and bifunctional aldehydes, ketones, and imines.
- Wei, Jianwei,Zhao, Liang,He, Cheng,Zheng, Sijia,Reek, Joost N. H.,Duan, Chunying
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p. 12707 - 12716
(2019/09/04)
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- Method for preparing initiating agent monomer containing azobenzene structure
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The invention discloses an azobenzene compound and a synthesis method thereof.The synthesis method in the technical scheme includes the steps that 4-nitrophenol, halohydrin and potassium hydroxide serve as raw materials to synthesize p-nitrobenzene oxygen alcohol; the p-nitrobenzene oxygen alcohol, iron powder and ammonium chloride are reacted to obtain p-aminophenyl oxygen alcohol; a typical diazo coupling reaction is carried out to obtain solid product 4-acrylic acid (N-methyl amino) ethyl alcohol-4'-aminoethanol-azobenzene; the products, 2-bromoisobutyryl bromide and triethylamine are reacted to obtain the final product 4-acrylic acid (N-methyl amino) ethyl alcohol-4'-bromoisobutyric acid alcohol ester base-azobenzene, and washing and vacuum drying are carried out.The azo compound contains azobenzene photochromic groups, carbon-carbon double bonds and active-tail-end bromine atoms at the same time, can serve as a self-trigger monomer to synthesize branched polymers containing the functional azobenzene structures with the atom transfer radical polymerization (ATRP) method, and has potential application photoresponse polymers.
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Paragraph 0043; 0044; 0045
(2017/01/17)
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- Using N-nitrosodichloroacetamides to conveniently convert linear primary amines into alcohols
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The reported rearrangement of N-nitrosodichloroacetamides provides a practicalmethod for converting primary amines into primary alcohols. The reaction sequence is operationally simple, requires only a single purification, and is compatible with a number of common functional groups. Mechanistic studies of the nitrosylation and rearrangement reactions illustrate the increased utility of dichloroacetamides compared to various other amides for this transformation.
- Macarthur, Nicholas S.,Wang, Linshu,Mccarthy, Blaine G.,Jakobsche, Charles E.
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p. 2014 - 2021
(2015/08/18)
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- Compounds for binding and imaging amyloid plaques and their use
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The present invention relates to novel compounds (3-aminopropen-1-ones) useful for binding and imaging beta amyloid deposits and their use in detecting or treating Alzheimer's disease and amyloidosis.
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Page/Page column 16
(2012/09/25)
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- TRIAZOLE COMPOUNDS AND METHODS OF MAKING AND USING THE SAME
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The present invention provides triazole macrocyclic compounds useful as therapeutic agents. More particularly, these compounds are useful as anti-infective, anti-proliferative, anti-inflammatory, and prokinetic agents.
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Page/Page column 145
(2008/06/13)
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- DRUG-POLYMER CONJUGATES
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This invention relates to a polypeptide-polymer conjugate that includes a polypeptide moiety, a polyalkylene oxide moiety, a linker connecting the polypeptide moiety with the polyalkylene oxide moiety, a first linkage between the polypeptide moiety and th
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Page/Page column 11
(2010/11/28)
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- 4′-Alkoxyl substitution enhancing the anti-mitotic effect of 5-(3′,4′,5′-substituted)anilino-4-hydroxy-8-nitroquinazolines as a novel class of anti-microtubule agents
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Mitosis inhibitors are powerful anticancer drugs. Based on a novel anti-microtubule agent of 5-(4′-methoxy)anilino-4-hydroxy-8-nitroquinazoline, a series of 5-(3′,4′,5′-substituted)anilino-4-hydroxy-8- nitroquinazolines were designed and synthesized to investigate the effect of the substitution on the inhibitory activity against mitotic progression of tumor cells. The large alkoxyl substitution on the 4′-position of 5-anilino ring is beneficial for the potency. The 5-(3′,4′,5′-trimethoxy)anilino-8-nitroquinazoline (1h) displays an overwhelming activity in arresting the cells at the G2/M phase, providing a promising new template for further development of potent microtubule-targeted anti-mitotic drugs.
- Jin, Yi,Zhou, Zu-Yu,Tian, Wei,Yu, Qiang,Long, Ya-Qiu
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p. 5864 - 5869
(2007/10/03)
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- A new strategy for synthesis of polymeric supports with triazene linkers
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A new strategy based on the use of diethylamine triazenes for stabilization and generation of polymer supported diazonium ions was described. New economical syntheses of four new polymeric supports with 3- and 6-carbon atom spacers and triazene linkers derived from meta- and para-aminophenol were described and compared to the traditional methods. The possible application of the polymer bound triazene masked diazonium salts as supports for immobilization of secondary amines (nortropine and 4-piperidinole and their esterification and oxidation), and as amine scavengers was shown. The new supports with meta-C3-T2 and para-C3-T2 linkers showed higher loadings and typically gave products with good yields and purities.
- Lazny, Ryszard,Nodzewska, Aneta,Klosowski, Piotr
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p. 121 - 130
(2007/10/03)
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- Synthesis of polymeric supports with spacer-modified triazene linkers: Aldol and Grignard reactions of immobilized nortropinone
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Four new polymeric supports with 3- and 6-carbon atom spacers and triazene linkers derived from meta- and para-aminophenol were synthesized from commercial Merrifield polymer. The supports could be used for immobilization of secondary amines in SPOS. A new strategy based on the use of diethylamine triazenes as masked precursors for the generation of polymer-supported diazonium ions was used. The performance of the new linkers was tested on Grignard and aldol reactions of solid-phase immobilized nortropinone. The new supports with C3-T2 linkers gave products with better yields and purities than the classical T2 supports or the supports with the C6-T2 linkers.
- Lazny, Ryszard,Nodzewska, Aneta
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p. 2441 - 2444
(2007/10/03)
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- Molecular rulers: New families of molecules for measuring interfacial widths
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Homologous series of solvatochromic neutral alcohols and ionic sulfates are synthesized and characterized. Each surfactant series consists of hydrophobic, p-nitroanisole-based chromophores attached to polar or ionic headgroups by n-alkyl spacers. UV absorption measurements show that the optical properties of surfactant chromophores closely track those of the parent chromophore. Interfacial tension measurements are used to calculate surface excess concentrations of ionic surfactants adsorbed to an aqueous-cyclohexane interface. With a hydrophobic chromophore, a hydrophilic headgroup, and a variable-length, alkyl spacer, these surfactants have the potential to function as molecular rulers: probes of molecular-scale variation in solvation forces across condensed-phase interfaces. Changing the separation between the hydrophobic, solvatochromic probe and the hydrophilic headgroup should enable different members of a homologous series to span different interfacial widths, thus exposing the chromophore to different chemical environments. This idea is explored by using surface-specific, nonlinear optical spectroscopy. Resonant second harmonic spectra of p-nitroanisole and the surfactant product 4a adsorbed to an aqueous-cyclohexane interface show the surfactant spectrum blue-shifted 9 nm relative to the spectrum of adsorbed p-nitroanisole. On the basis of chromophore solvatochromism, these results are consistent with a less polar environment surrounding the surfactant chromophore. Significant differences in interfacial solvation resulting from a ~5 A separation between the surfactant headgroup and chromophore support recently proposed models of molecularly sharp, microscopically flat aqueous-alkane interfaces.
- Steel, William H.,Damkaci, Fehmi,Nolan, Ryan,Walker, Robert A.
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p. 4824 - 4831
(2007/10/03)
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- AlCl3-N,N-Dimethylaniline: A Novel Benzyl and Allyl Ether Cleavage Reagent
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A combination system of AlCl3-N,N-dimethylaniline was found to cleave benzyl ethers readily to give parent alcohols in excellent yields.The system also cleaved allyl as well as methyl ethers.Numerous functional groups such as benzoyloxy, phenylthio, and olefinic double bond were not affected.Comparison of AlCl3-N,N-dimethylaniline and AlCl3-anisole were described.
- Akiyama, Takahiko,Hirofuji, Hajimu,Ozaki, Shoichiro
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p. 1932 - 1938
(2007/10/02)
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