- Emission enhancement by formation of aggregates in hybrid chromophoric surfactant amphiphile/silica nanocomposites
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(Figure Presented) In best order: Nanoaggregates of chromophores formed in a controlled fashion in self-assembled functional hybrid nanocomposites enhance fluorescence (see scheme). These hybrids minimize the problem of solid-state quenching and are thus applicable in the fabrication of electroluminescence devices.
- Bhongale, Chetan Jagdish,Hsu, Chain-Shu
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Read Online
- Novel κ2-Nim,S- and κ4-C,Nim,(μ-S),(μ-S)-coordination of di-2-thienyl ketone thiosemicarbazone (dtktsc). Hydrogen evolution and catalytic properties of palladacyclic [Pd(κ4-C,Nim,(μ-S),(μ-S)-dtktsc-2H)]4
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The reaction between di-2-thienyl ketone thiosemicarbazone, dtktsc, (1) and Zn(OAc)2·2H2O in ethanol produced [Zn(κ2-Nim,S-dtktsc-H)2] (2). When PdCl2(CH3CN)2 was used in place Zn(OAc)2·2H2O novel [Pd(κ4-C,Nim,(μ-S),(μ-S)-dtktsc-2H)]4 (3) was isolated. These reactions are in contrast with those reported for the synthesis of [Zn(κ3-Npy,Nim,S-dpktsc-H)2] and [PdCl(κ3-Npy,Nim,S),PdCl2(κ2-Npy,Nam)-dpktsc-H)] ? CH3CN when di-2-pyridyl ketone thiosemicarbazone (dpktsc) was used in place of 1. The identities of 2 and 3 were established from results of their elemental compositions, spectroscopic and electrochemical properties. The κ2-Nim,S-coordination of the imide deprotonated dtktsc (dtktsc-H)– to the Zn(II) ion was established from 13C and 1H NMR measurements. X-ray structural analysis on a single crystal of 3 ? dmf confirmed the κ4-Nim,C,(μ-S),(μ-S)-coordination of amide deprotonated and thienyl metallated dtktsc (dtktsc-2H)2- to the Pd(II) ion. In acidic or basic media 2 suffers dissociation, while 3 is stable under similar conditions. Electrochemical measurements on dmf solutions of 2 and 3, along with electrochemical reactions of dtktsc with Zn(OAc)2·2H2O and PdCl2(CH3CN)2 revealed facile coordination of dtktsc to the metal ions. The palladacyclic 3 shows good electro-catalytic behavior toward proton reduction and moderate catalytic activity toward C[sbnd]C cross-coupling reactions.
- Bakir, Mohammed,Bohari Yamin, M.,Lawrence, Mark W.
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Read Online
- Nitrogen-containing compound, electronic element, and electronic device
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The invention provides a nitrogen-containing compound shown as a chemical formula 1, an electronic element and an electronic device, and belongs to the technical field of organic materials. The structural formula of the nitrogen-containing compound is shown as a chemical formula 1, wherein Ar1 and Ar2 are selected from substituted or unsubstituted aryl with the carbon atom number of 6-30, substituted or unsubstituted heteroaryl with the carbon atom number of 3-30 and substituted or unsubstituted naphthenic base with the carbon atom number of 3-20; Ar3 is selected from substituted or unsubstituted aryl with the carbon atom number of 6-20 and substituted or unsubstituted heteroaryl with the carbon atom number of 3-20.
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Paragraph 0157-0159
(2021/01/29)
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- Transition-Metal-Free Borylation of Aryl Bromide Using a Simple Diboron Source
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In this study, we developed a simple transition-metal-free borylation reaction of aryl bromides. Bis-boronic acid (BBA), was used, and the borylation reaction was performed using a simple procedure at a mild temperature. Under mild conditions, aryl bromides were converted to arylboronic acids directly without any deprotection steps and purified by conversion to trifluoroborate salts. The functional group tolerance was considerably high. The mechanism study suggested that this borylation reaction proceeds via a radical pathway.
- Han, Min Su,Lim, Taeho,Ryoo, Jeong Yup
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p. 10966 - 10972
(2020/09/23)
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- Asymmetric 1,4-Addition of Arylboronic Acids to β,γ-Unsaturated α-Ketoesters using Heterogeneous Chiral Metal Nanoparticle Systems
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Asymmetric 1,4-addition reactions with β,γ-unsaturated α-ketoesters are valuable because the resulting chiral ketoester compounds can be converted into various useful species that are often used as chiral building blocks in drug and natural product synthesis. However, β,γ-unsaturated α-ketoesters have two reactive points in terms of nucleophilic additions, which will lead to the 1,4-adduct, the 1,2-adduct and to the combined 1,4- and 1,2-adduct. Therefore, controlling this chemoselectivity is an important factor for the development of these transformations. Here, we developed an asymmetric 1,4-addition of aryl boronic acids to β,γ-unsaturated α-ketoesters by using heterogeneous chiral rhodium nanoparticle systems with a chiral diene ligand bearing a secondary amide moiety. The newly developed polydimethylsilane-immobilized rhodium nanoparticle catalysts showed high activity, high chemoselectivity, and excellent enantioselectivity, and this is the first heterogeneous catalytic system for this asymmetric reaction. Metal nanoparticle catalysts were recovered and reused without loss of activity or leaching of metal. (Figure presented.).
- Miyamura, Hiroyuki,Yasukawa, Tomohiro,Zhu, Zhiyuan,Kobayashi, Shū
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supporting information
p. 353 - 359
(2019/12/15)
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- Magnesium promoted autocatalytic dehydrogenation of amine borane complexes: A reliable, non-cryogenic, scalable access to boronic acids
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Owing to the unusual reactivity of dialkylamine-borane complexes, a methodology was developed to simply access boronic acids. The intrinsic instability of magnesium aminoborohydride was tweaked into a tandem dehydrogenation borylation sequence. Proceeding via an autocatalytic cycle, amineborane dehydrogenation was induced by a variety of Grignard reagents. Overall, addition of the organomagnesium species onto specially designed dialkylamine-borane complexes led to a variety of boronic acids in high yields. In addition, the reaction can be performed under Barbier conditions, on a large scale.
- Marciasini, Ludovic D.,Richard, Jimmy,Cacciuttolo, Bastien,Sartori, Guillaume,Birepinte, Melodie,Chabaud, Laurent,Pinet, Sandra,Pucheault, Mathieu
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p. 164 - 171
(2018/12/05)
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- Copper-Catalyzed Monoorganylation of Trialkyl Borates with Functionalized Organozinc Pivalates
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Organozinc pivalates, a recently developed air- and moisture-stable organozinc species, were found for the first time as excellent organometallic species in the monoorganylation of trialkyl borates whereby boronic acids were prepared in high yields. The significant advantage of organozinc pivalates over another previously employed organometallic reagents, e. g., organolithium reagents, Grignard reagents and organozinc halides, is that the generation of multiorganylation byproducts such as borinic acids and trialkylboranes were completely suppressed. Additionally, the in situ generated boronates could be directly arranged into Suzuki-Miyaura type cross-coupling reactions to produce biaryls in high yields.
- Fu, Ying,Gou, Bei-Lei,Shi, Chun-Zhao,Du, Zhengyin,Shen, Tong
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p. 4253 - 4257
(2018/09/18)
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- BLUE FLUORESCENT DOPANT MATERIALS, AND ORGANIC THIN FILM AND ORGANIC LIGHT EMITTING DEVICES COMPRISING THE SAME
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The present invention refers to one or more layers including a light emitting layer between anode and cathode is interposed as above wherein at least one of an organic electroluminescent device, comprising of a luminescent layer for organic thin film layer contains said formula 1, formula 2 characterized in that said hole transport material to the light emitting layer employed in conjunction with an organic electroluminescence device number under public affairs substrate. The organic electroluminescence device of the present invention exhibits high efficiency and long lifetime properties. [Formula 1][Formula 2] (by machine translation)
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Paragraph 0184; 0185; 0186; 0187; 0188
(2017/06/23)
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- 1, 3, 5 - cyclohexanetriol - cis - or organic boronic acid-stable siloxy inositol complex and organic synthetic reaction using a reagent art
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PROBLEM TO BE SOLVED: To provide a stable ate-type complex of an organoboronic acid as a reagent for organic synthesis reaction; and manufacturing techniques thereof.SOLUTION: A stable ate-type complex of an organoboronic acid with scyllo-inositol or 1,3,5-cis-cyclohexanetriol comprises an anion represented by the specified general formula (I) or (II) as a constituent. In the formula, Rand Reach represent an alkyl group, alkenyl group, alkynyl group, aryl group, heterocyclic group or aralkyl group which may have substituents.
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Paragraph 0167; 0168
(2017/06/02)
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- Construction of Vesicles, Micro/Nanorods and Ultralong Nanotubes through the Self-Assembly of Non-Classical Amphiphiles with Rigid Conformation
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Amphiphilic molecules have long been regarded as an important class of supramolecular building blocks for the fabrication of nanomaterials. While most previous researches have mainly focused on amphiphlies with flexible structures, in this work, four novel amphiphiles possessing wholly-rigid skeletons have been designed and synthesized. These molecules were built by using 4,4’-bipyridin-1-ium or viologen as hydrophilic moieties and phenyl or biphenyl as hydrophobic segments, bridged by a pyridazine unit. Their self-assembly behavior has been investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM) and transmission electron microscopy (TEM), which revealed they could self-assemble into well-ordered nanoarchitectures with various morphologies such as vesicles, micro/nanorods and nanotubes in water or methanol, depending on their hydrophilic/hydrophobic fraction ratios.
- Lin, Feng,Liang, Rongran,Qi, Qiaoyan,Zhan, Tianguang,Li, Zhanting,Zhao, Xin
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p. 429 - 434
(2017/04/27)
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- Spectroscopic Studies of the Chan-Lam Amination: A Mechanism-Inspired Solution to Boronic Ester Reactivity
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We report an investigation of the Chan-Lam amination reaction. A combination of spectroscopy, computational modeling, and crystallography has identified the structures of key intermediates and allowed a complete mechanistic description to be presented, including off-cycle inhibitory processes, the source of amine and organoboron reactivity issues, and the origin of competing oxidation/protodeboronation side reactions. Identification of key mechanistic events has allowed the development of a simple solution to these issues: manipulating Cu(I) → Cu(II) oxidation and exploiting three synergistic roles of boric acid has allowed the development of a general catalytic Chan-Lam amination, overcoming long-standing and unsolved amine and organoboron limitations of this valuable transformation.
- Vantourout, Julien C.,Miras, Haralampos N.,Isidro-Llobet, Albert,Sproules, Stephen,Watson, Allan J. B.
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supporting information
p. 4769 - 4779
(2017/04/11)
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- COMPOUND FOR ORGANIC ELECTRONIC ELEMENT, ORGANIC ELECTRONIC ELEMENT USING THE SAME, AND AN ELECTRONIC DEVICE THEREOF
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The present invention provides a novel compound capable of improving light emitting efficiency, stability and lifespan of an element, an organic electronic element using the same and an electronic device thereof.(110) Substrate(120) Positive electrode(130) Hole injection layer(140) Hole transfer layer(141) Buffer layer(150) Light emitting layer(151) Light-emitting assisting layer(160) Electron transfer layer(170) Electron injection layer(180) Negative electrodeCOPYRIGHT KIPO 2016
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Paragraph 0271-0275
(2016/10/07)
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- One-Pot Homologation of Boronic Acids: A Platform for Diversity-Oriented Synthesis
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Formal homologation of sp2-hybridized boronic acids is achieved via cross-coupling of boronic acids with conjunctive haloaryl BMIDA components in the presence of a suitably balanced basic phase. The utility of this approach to provide a platform for diversity-oriented synthesis in discovery medicinal chemistry is demonstrated in the context of the synthesis of a series of analogues of a BET bromodomain inhibitor.
- Muir, Calum W.,Vantourout, Julien C.,Isidro-Llobet, Albert,Macdonald, Simon J. F.,Watson, Allan J. B.
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supporting information
p. 6030 - 6033
(2016/01/09)
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- Speciation control during Suzuki-Miyaura cross-coupling of haloaryl and haloalkenyl MIDA boronic esters
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Boronic acid solution speciation can be controlled during the Suzuki-Miyaura cross-coupling of haloaryl N-methyliminodiacetic acid (MIDA) boronic esters to enable the formal homologation of boronic acid derivatives. The reaction is contingent upon control of the basic biphase and is thermodynamically driven: temperature control provides highly chemoselective access to either BMIDA adducts at room temperature or boronic acid pinacol ester (BPin) products at elevated temperature. Control experiments and solubility analyses have provided some insight into the mechanistic operation of the formal homologation process.
- Fyfe, James W. B.,Valverde, Elena,Seath, Ciaran P.,Kennedy, Alan R.,Redmond, Joanna M.,Anderson, Niall A.,Watson, Allan J. B.
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supporting information
p. 8951 - 8964
(2015/06/08)
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- SPIRO-SUBSTITUTED OXINDOLE DERIVATIVES HAVING AMPK ACTIVITY
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The present invention relates to compounds of formula (I), which have valuable pharmacological properties, in particular are activators of AMPK and which are therefore useful in the treatment of certain disorders that can be prevented or treated by activation of this receptor. The compounds are suitable for treatment and prevention of diseases which can be influenced by this receptor, such as metabolic diseases, in particular diabetes type 2.
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Page/Page column 72; 89; 90
(2015/01/07)
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- OLEFIN SUBSTITUTED OXINDOLES HAVING AMPK ACTIVITY
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The present invention relates to compounds of formula (I), which have valuable pharmacological properties, in particular are activators of AMPK and which are therefore useful in the treatment of certain disorders that can be prevented or treated by activation of this receptor. The compounds are suitable for treatment and prevention of diseases which can be influenced by this receptor, such as metabolic diseases, in particular diabetes type 2.
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Page/Page column 60; 81; 82
(2015/01/07)
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- Nickel-catalyzed borylation of halides and pseudohalides with tetrahydroxydiboron [B2(OH)4]
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Arylboronic acids are gaining increased importance as reagents and target structures in a variety of useful applications. Recently, the palladium-catalyzed synthesis of arylboronic acids employing the atom-economical tetrahydroxydiboron (BBA) reagent has been reported. The high cost associated with palladium, combined with several limitations of both palladium- and copper-catalyzed processes, prompted us to develop an alternative method. Thus, the nickel-catalyzed borylation of aryl and heteroaryl halides and pseudohalides using tetrahydroxydiboron (BBA) has been formulated. The reaction proved to be widely functional group tolerant and applicable to a number of heterocyclic systems. To the best of our knowledge, the examples presented here represent the only effective Ni-catalyzed Miyaura borylations conducted at room temperature.
- Molander, Gary A.,Cavalcanti, Livia N.,Garcia-Garcia, Carolina
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p. 6427 - 6439
(2013/07/26)
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- NOVEL ORGANIC ELECTROLUMINESCENT COMPOUNDS AND ORGANIC ELECTROLUMINESCENT DEVICE USING THE SAME
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Provided are novel organic electroluminescent compounds, and organic electroluminescent devices comprising the same. Since the organic electroluminescent compounds exhibit high luminous efficiency in blue color, and excellent life property of the material, they may be used to manufacture OLEDs having very good operation life.
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Page/Page column 18; 19; 21; 22
(2011/09/30)
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- Synthesis-guided structure revision of the sarcodonin, sarcoviolin, and hydnellin natural product family
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A sweeping structural revision of the sarcodonin natural product family (published structures 1a-13a) is proposed after extensive studies aimed at their chemical synthesis. Key features of revised structure 1b include replacement of the N,N-dioxide moiety with an oxime, ring-opening of the central diketopiperazine, and transposition of the terphenyl wing from the 1β-2β position of 1a to the 2β-3β position of 1b. This structure revision arose from the serendipitous synthesis of a benzodioxane aminal (44) whose structure was unambiguously determined by X-ray crystallography and whose spectral properties bore considerable resemblance to the published data for the sarcodonins. A versatile new method for O-arylation of hydroxamic acids is also reported herein, as well as a manganese(III)- mediated α-oxidation of hydroxamic acids to aminals.
- Lin, David W.,Masuda, Takeshi,Biskup, Moritz B.,Nelson, Jonathan D.,Baran, Phil S.
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supporting information; experimental part
p. 1013 - 1030
(2011/04/15)
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- Synthesis of nonsymmetrical 5-Aryl-2-indolopyrrole derivatives via controlled mono Suzuki-Miyaura cross-coupling on N-Boc-2,5-dibromopyrrole
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The first example of mono Suzuki-Miyaura cross-coupling of N-Boc-2,5-dibromopyrrole with a boronic acid (indol-2-ylboronic acid) is reported. The resulting 2-indolyl-5-bromopyrrole derivative was in turn coupled with a variety of aryl- or heteroarylboronic acids thereby providing the corresponding non-symmetrical 2,5-disubstituted pyrroles in good to excellent yields. The tert-butoxycarbonyl (Boc) groups could be easily removed to give the completely deprotected products. Georg Thieme Verlag Stuttgart - New York.
- Beaumard, Floriane,Dauban, Philippe,Dodd, Robert H.
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experimental part
p. 4033 - 4042
(2011/02/22)
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- Multiple C-H activations to construct biologically active molecules in a process completely free of organohalogen and organometallic components
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(Chemical Equation Presented) Step by step: Highly selective cross dehydrogenase arylation of acetanilides was developed to construct biaryls under mild condition. With this method, different aryl C-H bonds were activated in sequential reactions to construct functionalized carbazoles (see scheme), which are present as key structural units in various biological molecules and organic optical materials.
- Li, Bi-Jie,Tian, Shi-Liang,Fang, Zhao,Shi, Zhang-Jie
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p. 1115 - 1118
(2008/09/21)
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- Synthesis of polyarene derivatives of fused aziridines by Suzuki-Miyaura cross-coupling
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A convenient and effective synthetic approach to potentially radiochromic polyarene derivatives of bi- and tricyclic aziridines utilizing modified Suzuki-Miyaura cross-coupling with catalysis in micellar media has been developed. A series of polyarene substituents were introduced into 1,5-diaryl-3,5a-dihydro-1H-azireno[1,2-c]imidazoles, 1,6-diaryl-1,3,4,6a-tetrahydroazireno[1,2-a]pyrazines, and 1,2-diaryl-1,1a-dihydroazireno[1,2-a]quinoxalines without degradation of the highly reactive aziridine ring system.
- Zbruyev, Alexander I.,Vashchenko, Valery V.,Andryushchenko, Anastasiya A.,Desenko, Sergey M.,Musatov, Vladimir I.,Knyazeva, Irina V.,Chebanov, Valentin A.
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p. 4297 - 4303
(2007/10/03)
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- NEW ANTHRACENE DERIVATIVES, PREPARATION METHOD THEREOF AND ORGANIC LIGHT EMITTING DIODE USING THE SAME
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The present invention provides a novel anthracene derivative, a method for preparing the same, and an organic electronic device using the same. The anthracene derivative according to the invention can function alone as a light emitting host, in particular, as a blue host in an organic electronic device. Further, the anthracene derivative according to the invention can also function as a hole injecting or hole transporting material, an electron injecting or electron transporting material, or a light emitting material in an organic electronic device including a light emitting device. Therefore, the organic electronic device according to the present invention shows excellent characteristics in efficiency, drive voltage and stability.
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Page/Page column 62
(2010/11/28)
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- Synthesis of 8-substituted xanthine derivatives by Suzuki cross-coupling reaction
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A Suzuki cross-coupling reaction procedure was developed to prepare 8-substituted 3,7-dihydropurine-2,6-dione (xanthine) derivatives. 8-Halogen-substituted xanthines were reacted with phenyl- and styrylboronic acids. The best results were obtained using tetrakis(triphenylphosphine)palladium(0) and tripotassium phosphate in dimethylformamide. The developed procedure allows for a convergent synthesis of pharmacologically active 8-substituted xanthine derivatives.
- Vollmann, Karl,Mueller, Christa E.
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p. 871 - 879
(2007/10/03)
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- Formation of boroxine: Its stability and thermodynamic parameters in solution
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Condensation of three boronic acids proceeding at room temperature gave their corresponding boroxines; NMR spectral measurements revealed that the reaction was reversible at room temperature, that electron-donating groups supported the formation of boroxine, and that entropically driven forces promoted the formation of boroxine in solution.
- Tokunaga, Yuji,Ueno, Hiroki,Shimomura, Youji,Seo, Toshihiro
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p. 787 - 790
(2007/10/03)
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- Javelin-, hockey stick-, and boomerang-shaped liquid crystals. Structural variations on p-quinquephenyl
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The ramifications of changing molecular geometry in a series of all-aromatic liquid crystals derived from p-quinquephenyl are reported. Substituting heterocyclic rings such as thiophene, oxadiazole, oxazole, or 1,3-phenylene into the p-quinquephenylene core affects molecular shape changes via the substituent's exocyclic bond angle. In general, we found that introducing nonlinearity into molecules depresses the melting transition temperature. The symmetric (boomerang-shaped) molecules, 2,5-bisbiphenyl-4-yl-1,3,4-oxadiazole, 2,5-bisbiphenyl-4-yl-oxazole, and 1,3-bisbiphenyl-4-yl-benzene, melt into isotropic phases showing small monotropic mesophases. By contrast, the asymmetric (hockey stick-shaped) mesogens, 2-terphenyl-4-yl-5-phenyl thiophene and 2-terphenyl-4-yl-5-phenyl-1,3,4-oxadiazole, exhibit more stable enantiotropic liquid crystalline phases. The hockey stick-shaped mesogens exhibit a smectic phase as well as a nematic phase. High-temperature X-ray determination of the smectic layer spacing gives an unambiguous picture of interdigitated, bilayerlike supramolecular architecture in the smectic phase. There are associated changes in the mesogen's electrostatic profile when a heterocycle is introduced into the quinquiphenylene framework (e.g., conjugation is perturbed). Our findings suggest that steric packing considerations dominate the phase preferences (nematic versus smectic phases). However, electronic considerations (conjugation) appear to control the range of mesomorphism in this new family of nonlinear liquid crystals.
- Dingemans, Theo J.,Murthy, N. Sanjeeva,Samulski, Edward T.
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p. 8845 - 8860
(2007/10/03)
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- Arylation of 8-acetoxyoctalenone in a nickel-catalyzed coupling reaction with lithium arylborates
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In order to find a suitable organometallic compound and a catalyst for the arylation of 8-acetoxyoctalenone 4 (a stereoisomeric mixture of 4α and 4β), phenylation was first investigated with PhZnX (7: X = Cl; 8: X = Br)/Pd or Ni cat., PhSnBu3 (9)/Pd cat. and LiCl, and [PhB(Bu)(OCHMeCH-MeO)]Li (10a)/Ni cat. Borate 10a provided the desired product 11a with high stereoselectivity. The stereochemical outcome was irrespective of the stereochemistry of the acetoxy group in 4. Four more aryl groups, p-R-C6H4 (R = Me, MeO, Ph, and Me2N), were installed stereoselectively with this method.
- Kobayashi, Yuichi,Ito, Michiko
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p. 3393 - 3397
(2007/10/03)
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- Structural Effects on Electrical Conduction of Conjugated Molecules Studied by Scanning Tunneling Microscopy
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We have studied electrical conduction of conjugated molecules with phenyl rings embedded into alkanethiol self-assembled monolayers (SAMs), to investigate the molecular structural effect on the electrical conduction. Scanning tunneling microscope (STM) images of this surface revealed that the conjugated molecules with phenyl rings adsorbed mainly on defects and domain boundaries of the pre-assembled alkanethiol (nonanethiol C9) SAM and formed conjugated domains. In the case of conjugated molecules with one or three methylene groups between the sulfur and phenyl rings, the measured height of the conjugated molecular domains depended on their lateral sizes, while a strong dependence was not observed in the case of conjugated molecules without a methylene group. By analyzing size dependence on the height of the conjugated molecular domain, we could evaluate the electronic conductivity of the molecular domains. As a result of the analysis, to increase the vertical conduction of the molecular domains, one methylene group was found to be necessary between the sulfur and aromatic phenyl rings. Local barrier heights on the conjugated molecular domains in all the cases were larger than on the C9 SAM surface, suggesting that the increase in the vertical conductivitity is not likely to be due to the lowering of the local barrier height, but can be attributed to the conjugated molecular adsorption. X-ray photoelectron spectra (XPS) and ultraviolet light photoelectron spectra (UPS) revealed that the carrier density among conjugated molecular SAMs does not depend on the number of methylene groups between the sulfur and phenyl rings, suggesting that the higher vertical conduction of conjugated molecules with one methylene group can probably be attributed to higher transfer probability of carriers during the STM measurements.
- Ishida, Takao,Mizutani, Wataru,Choi, Nami,Akiba, Uichi,Fujihira, Masamichi,Tokumoto, Hiroshi
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p. 11680 - 11688
(2007/10/03)
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- Metalloproteinase inhibitors, pharmaceutical compositions containing them, and their use
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The present invention is directed to compound of the formula I: STR1 wherein R1, R2, R3, R4, R5, X, Y, and STR2 are as defined herein. These compounds are useful for inhibiting the activity of a metalloproteinase by contacting the metalloproteinase with an effective amount of the inventive compounds.
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- Determination of the Absolute Configuration of 1-Arylethane-1,2-diols by a Nonempirical Analysis of the CD Spectra of Their 4-Biphenylboronates
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(matrix presented) 1-Arylethane-1,2-diols 1, reacting with 4-biphenylboronic acid 2, form the conformationally defined boronates 3 where the aryl and biphenyl chromophores assume a fixed and known relative disposition. These chromophores thus define an exciton coupled system, whose chirality (revealed by the sign of the biphenyl CD band at 260 nm) allows an unambiguous assignment of the absolute configuration of the stereogenic center. This approach provides the hitherto unreported absolute configuration of diols 1c-f.
- Superchi, Stefano,Donnoli, Maria Irene,Rosini, Carlo
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p. 2093 - 2096
(2008/02/09)
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- Strong inhibitory effect of sugar-biphenylylboronic acid complexes on the hydrolytic activity of α-chymotrypsin
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Boronic acids act as transition-state analogues for certain peptidases. the inhibitory effect of 2-, 3- and 4-biphenylylboronic acids (2a, 2b and 2c) on the hydrolytic activity of α-chymotrypsin has been investigated.These inhibitors were employed to monitor the binding event occuring in the active site by a fluorescence method.It was shown that the decrease in the fluorescence intensity, which is induced by the formation of a covalent bond with the boronic acid moiety, is well correlated with the inhibitory effect estimated by kinetic measurements.The inhibitory effect appeared in the order 2a i = 1.6 x 10-6 mol dm-3).Intetrestingly, the inhibitory effect was further intensified by added saccharides.In particular, the combined system of 2b and D-glucose strongly inhibited the enzyme reaction, the inhibitory effect (Ki = 1.1 x 10-7 mol dm-3) being stronger than that of a specific inhibitor, chymostatin (Ki = 4.8 x 10-7 mol dm-3).Hence, saccharides act as a 'co-inhibitor' in the boronic acid inhibition system.This is a novel and efficient inhibition system for α-chymotrypsin (and probably more generally for other peptidases).
- Suenaga, Hikaru,Mikami, Masafumi,Yamamoto, Hiromasa,Harada, Takaaki,Shinkai, Seiji
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p. 1733 - 1738
(2007/10/02)
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