- Light Harvesting for Rapid and Selective Reactions: Click Chemistry with Strain-Loadable Alkenes
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Intramolecular strain is a powerful driving force for rapid and selective chemical reactions, and it is the cornerstone of strain-induced bioconjugation. However, the use of molecules with built-in strain is often complicated as a result of instability or selectivity issues. Here, we show that such strain, and subsequent cycloadditions, can be mediated by visible light via the harvesting of photochemical energy. Through theoretical investigations and molecular engineering of strain-loadable cycloalkenes, we demonstrate the rapid chemoselective cycloaddition of alkyl azides with unstrained cycloalkenes via the transiently (reversibly) formed trans-cycloalkene. We assess this system via the rapid bioconjugation of azide-functionalized insulin. An attractive feature of this process is the cleavable nature of the linker, which makes a catch-and-release strategy possible. In broader terms, we show that conversion of photochemical energy to intramolecular ring strain is a powerful strategy that can facilitate complex chemical transformations, even in biomolecular systems. Probing, isolating, and/or manipulating biologically relevant macromolecules is central to the study of their function in living systems. However, the synthetic tools available for performing the chemistry necessary for such studies are often difficult to use or limited in utility. In the approach presented here, light is converted to molecular strain energy, which can in turn be used for performing rapid and highly selective chemistry on macromolecular systems. Because it involves chemically stable and chemoselective reactions, this research not only opens up new possibilities for biomolecular functionalization and manipulation but also promises to make such experiments accessible to a broader class of researchers. The central concept of strain-loadable alkenes is general and provides a firm foundation for light-activated chemistry in complex environments. Strain-loadable alkenes are cycloalkenes that, when irradiated in the presence of a visible-light-absorbing photocatalyst, undergo double-bond isomerization. Because of engineered geometrical constraints, this isomerization results in significant molecular strain. Weaver and colleagues exploit this strain to dramatically accelerate the cycloaddition with azides, which are otherwise unreactive, in mixed molecular environments.
- Singh, Kamaljeet,Fennell, Christopher J.,Coutsias, Evangelos A.,Latifi, Reza,Hartson, Steve,Weaver, Jimmie D.
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supporting information
p. 124 - 137
(2018/01/17)
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- SUBSTITUTED POLYCYCLIC ANTIBACTERIAL COMPOUNDS
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The present description relates to substituted polycyclic compounds of Formula (I), Formula (II) or Formula (III): wherein the dashed line represents an optional double bond and Rl, R2, R4, R5, R7, X and Z are as defined herein, and forms and compositions thereof, and also relates to uses of a compound of Formula (I), Formula (II) or Formula (III) or a form thereof and methods for treating or ameliorating Neisseria gonorrhoeae (N. gonorrhoeae) in a subject in need thereof comprising, administering an effective amount of the compound to the subject.
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Page/Page column 128
(2016/02/29)
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- Nitration chemistry in continuous flow using fuming nitric acid in a commercially available flow reactor
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The paper will describe the use of flow chemistry for scaling up exothermic or hazardous nitration reactions. Such reactions often cause time delays to the delivery of larger batches of intermediates or final compounds for medicinal chemistry projects, be
- Brocklehurst, Cara E.,Lehmann, Hansjoerg,La Vecchia, Luigi
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experimental part
p. 1447 - 1453
(2012/01/12)
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- Tricyclic pyrazoles. 3. Synthesis, biological evaluation, and molecular modeling of analogues of the cannabinoid antagonist 8-chloro-1-(2′, 4′-dichlorophenyl)-N-piperidin-1-yl-1,4,5,6-tetrahydrobenzo[6,7] cyclohepta[1,2-c]pyrazole-3-carboxamide
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A series of analogues of 8-chloro-1-(2′,4′-dichlorophenyl)-AT- piperidin-1-yl-1,4,5,6-tetrahydrobenzo-[6,7]cyclohepta[1,2-c] pyrazole-3-carboxamide 4a (NESS 0327) (Ruiu, S.; Pinna, G. A.; Marchese, G.; Mussinu, J. M.; Saba, P.; Tambaro, S.; Casti, P.; Var
- Murineddu, Gabriele,Ruiu, Stefania,Loriga, Giovanni,Manca, Ilaria,Lazzari, Paolo,Reali, Roberta,Pani, Luca,Toma, Lucio,Pinna, Gérard A.
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p. 7351 - 7362
(2007/10/03)
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- Synthesis and structure-activity studies on N-[5-(1H-imidazol-4-yl)-5,6,7,8-tetrahydro-1-naphthalenyl]methanesulfonamide, an imidazole-containing α1A-adrenoceptor agonist
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Structure-activity studies were performed on the α 1A-adrenoceptor (AR) selective agonist N-[5-(1H-imidazol-4-yl)-5,6,7,8-tetrahydro-1-naphthalenyl]methanesulfonamide (4). Compounds were evaluated for binding activity at the α1A, α1b, α1d, α2a, and α2B subtypes. Functional activity in tissues containing the α1A (rabbit urethra), α1B (rat spleen), α1D (rat aorta), and α2A (rat prostatic vas deferens) was also evaluated. A dog in vivo model simultaneously measuring intraurethral pressure (IUP) and mean arterial pressure (MAP) was used to assess the uroselectivity of the compounds. Many of the compounds that were highly selective in vitro for the α1A-AR subtype were also more uroselective in vivo for increasing IUP over MAP than the nonselective α1-agonists phenylpropanolamine (PPA) (1) and ST-1059 (2, the active metabolite of midodrine), supporting the hypothesis that greater α1A selectivity would reduce cardiovascular side effects. However, the data also support a prominent role of the α1A-AR subtype in the control of MAP.
- Altenbach, Robert J.,Khilevich, Albert,Kolasa, Teodozyj,Rohde, Jeffrey J.,Bhatia, Pramila A.,Patel, Meena V.,Searle, Xenia B.,Yang, Fan,Bunnelle, William H.,Tietje, Karin,Bayburt, Erol K.,Carroll, William A.,Meyer, Michael D.,Henry, Rodger,Buckner, Steven A.,Kuk, Jane,Daza, Anthony V.,Milicic, Ivan V.,Cain, John C.,Kang, Chae H.,Ireland, Lynne M.,Carr, Tracy L.,Miller, Thomas R.,Hancock, Arthur A.,Nakane, Masaki,Esbenshade, Timothy A.,Brune, Michael E.,O'Neill, Alyssa B.,Gauvin, Donna M.,Katwala, Sweta P.,Holladay, Mark W.,Brioni, Jorge D.,Sullivan, James P.
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p. 3220 - 3235
(2007/10/03)
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- 4-Imidazole derivatives of benzyl and restricted benzyl sulfonamides, sulfamides, ureas, carbamates, and amides and their use
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Compounds of formula I are useful in treating diseases prevented by or ameliorated with α1A agonists. Also disclosed are α1A agonist compositions and a method of activating α1 adrenoceptors in a mammal.
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- Imidazoles and related compounds as α1A agonists
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Compounds having formula I: are useful in treating diseases prevented by or ameliorated with α1Aagonists. Also disclosed are α1Aagonist compositions and a method of activating α1adrenoceptors in a mammal.
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- Substituted guanidine derivatives and process for producing the same
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A compound represented by the general formula (1): wherein each of R1, R2, R3, R4and R5is a hydrogen atom, an alkyl group, a substituted alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, a saturated heterocyclic group, an aromatic group, an acyl group or the like; each of Y1, Y2, Y3and Y4is a single bond, —CH2—, —O—, —CO— or the like, provided that at least two of Y1through Y4are independently a group other than a single bond; and Z may be absent, or one or more Zs may be present and are independently an alkyl group, a substituted alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, a saturated heterocyclic group, a halogen atom, a carboxyl group, an alkoxycarbonyl group, an aromatic group, an acyl group or the like, is useful as a therapeutic or prophylactic agent for diseases caused by the acceleration of the sodium/proton exchange transport system.
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Page column 56
(2010/01/31)
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