- Discovery of redox system enabling C–N–C bonds formation: Unprecedented Aza-Cannizzaro reaction
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A novel reaction involving in situ redox conversion of glyoxylate esters to glycine is described. Simple starting materials and mild conditions for the synthesis of glycine derivatives probably indicate a pathway towards prebiotic chemistry. This proceeds analogous to Cannizzaro reaction involving ammonia therefore it can be termed as intramolecular Aza-Cannizzaro type reaction. This reaction is examined in detail with an aid of computational analysis to corroborate the proposed mechanism.
- Sud, Abhishek,Chaudhari, Pramod S.,Agarwal, Ishu,Mohammad, Amjad Basha,Dahanukar, Vilas H.,Bandichhor, Rakeshwar
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Read Online
- Molecular symmetry and the design of molecular solids: The oxalamide functionality as a persistent hydrogen bonding unit
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A symmetry analysis based upon the structure of simple molecules and their anticipated intermolecular interactions can lead to successful predictions of molecular packing and crystal symmetry. As a demonstrated of these ideas an in-depth study of the oxalamide functionality as a persistent hydrogen bonding unit is presented. The synthesis and structural characterization of a series oxalamide dicarboxylic acids is presented and the structures compared with the analogous urea compounds. Both the urea and oxalamide dicarboxylic acids form designed two-dimensional hydrogen-bonded β-networks with a significant degree of reliability. The urea designs are quite reliable when there is a molecular 2-fold axis, but competing hydrogen bond patterns are found when less symmetrical molecules are studied. The oxalamide design based on inversion centers is also quite reliable, with the designed layer structure found in most cases.
- Coe, Seth,Kane, John J.,Nguyen, Tam Luong,Toledo, Leticia M.,Wininger, Eric,Fowler, Frank W.,Lauher, Joseph W.
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Read Online
- A Discrete 3d-4f Metallacage as an Efficient Catalytic Nanoreactor for a Three-Component Aza-Darzens Reaction
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The exploration and development of coordination nanocages can provide an approach to control chemical reactions beyond the bounds of the flask, which has aroused great interest due to their significant applications in the field of molecular recognition, supramolecular catalysis, and molecular self-assembly. Herein, we take the advantage of a semirigid and nonsymmetric bridging ligand (H5L) with rich metal-chelating sites to construct an unusual and discrete 3d-4f metallacage, [Zn2Er4(H2L)4(NO3)Cl2(H2O)]·NO3·xCH3OH·yH2O (Zn2Er4). The 3d-4f Zn2Er4cage possesses a quadruple-stranded structure, and all of the ligands wrap around an open spherical cavity within the core. The self-assembly of the unique cage not only ensures the structural stability of the Zn2Er4cage as a nanoreactor in solution but also makes the bimetallic lanthanide cluster units active sites that are exposed in the medium-sized cavity. It is important to note that the Zn2Er4cage as a homogeneous catalyst has been successfully applied to catalyze three-component aza-Darzens reactions of formaldehyde, anilines, and α-diazo esters without another additive under mild conditions, displaying better catalytic activity, higher specificity, short reaction time, and low catalyst loadings. A possible mechanism for this three-component aza-Darzens reaction catalyzed by the Zn2Er4cage has been proposed. These experimental results have demonstrated the great potential of the discrete 3d-4f metallacage as a host nanoreactor for the development of supramolecular or molecular catalysis.
- Bai, Dongjie,Cui, Xiang,Li, Jingzhe,Liu, Weisheng,Tang, Xiaoliang,Tang, Yu,Xu, Zhichuan J.,Zhang, Zhichao,Zhou, Shengbin
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supporting information
p. 4009 - 4017
(2022/03/08)
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- INTEGRASE INHIBITORS 3
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The present invention provides a method of treatment or prophylaxis of a viral infection in a subject comprising administering to said subject an effective amount of a compound of formula (I) or a pharmaceutically acceptable derivative, salt or prodrug thereof. Compounds of formula (I) are also provided.
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Page/Page column 63
(2008/06/13)
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- Development of a scaleable synthesis of a 3-aminopyrazinone acetamide thrombin inhibitor
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A scaleable route to 2-{3-[(2,2-difluoro-2-(2-pyridyl)ethyl)-animo]-6- chloro-2-oxohydropyrazinyl}-N-(3-fluoro(2-pyridyl))-methyl]acetamide 1 is described in which various scaleup issues were addressed to provide a safe, efficient, and robust route for th
- Ashwood, Michael S.,Alabaster, Ramon J.,Cottrell, Ian F.,Cowden, Cameron J.,Davies, Antony J.,Dolling, Ulf H.,Emerson, Khateeta M.,Gibb, Andrew D.,Hands, David,Wallace, Debra J.,Wilson, Robert D.
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p. 192 - 200
(2013/09/04)
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- Thrombin inhibitors
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Compounds of the invention are useful in inhibiting thrombin and associated thrombotic occlusions having the following structure:
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- Non-covalent thrombin inhibitors featuring P3-heterocycles with P1-monocyclic arginine surrogates
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Investigations on P2-P3-heterocyclic dipeptide surrogates directed towards identification of an orally bioavailable thrombin inhibitor led us to pursue novel classes of achiral, non-covalent P1-arginine derivatives. The design, synthesis, and biological activity of inhibitors NC1-NC30 that feature three classes of monocyclic P1-arginine surrogates will be disclosed: (1) (hetero)aromatic amidines, amines and hydroxyamidines, (2) 2-aminopyrazines, and (3) 2-aminopyrimidines and 2-aminotetrahydropyrimidines.
- Reiner, John E.,Siev, Daniel V.,Araldi, Gian-Luca,Cui, Jingrong Jean,Ho, Jonathan Z.,Reddy, Komandla Malla,Mamedova, Lala,Vu, Phong H.,Lee, Kuen-Shan S.,Minami, Nathaniel K.,Gibson, Tony S.,Anderson, Susanne M.,Bradbury, Annette E.,Nolan, Thomas G.,Semple, J. Edward
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p. 1203 - 1208
(2007/10/03)
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- Kilogram scale synthesis of the pyrazinone acetic acid core of an orally efficacious thrombin inhibitor
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A multi-kilogram scale synthesis of the orally efficacious thrombin inhibitor 1 has been achieved via construction of the pyrazinone core from an unsymmetric oxalic diamide. Key features include judicious choice of reagents to minimize side products, a ke
- Fleitz, Fred J.,Lyle, Terry A.,Zheng, Nan,Armstrong III, Joseph D.,Volante
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p. 3171 - 3180
(2007/10/03)
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- Synthesis of hydroxypiperidinecarboxylic acids from pyridinedicarboxylates
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(3RS,4SR,5SR)-5-Hydroxy-3-hydroxymethyl-4-piperidinecarboxylic acid 4,3′-lactone was synthesised in eight steps from ethyl glycinate via selective hydrolysis and reduction of 4,5-di-(methoxycarbonyl)-3-hydroxypyridine. The regioisomer (3RS,4RS,5SR)-5-hydr
- Damsgaard, Anders,Hazell, Rita,Bols, Mikael
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p. 521 - 527
(2007/10/03)
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- Synthesis of 4-hydroxy-6,9-difluorobenz[g]isoquinoline-5,10-diones and conversions to 4-hydroxy-6,9-bis[(aminoalkyl)amino]-benz[g]isoquinoline-5,10-diones
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Synthetic procedures have been developed which lead to 4-hydroxy-6,9-difluorobenz[g]isoquinoline-5,10-dione (4a) and its 3-methyl analogue 4b. Attempts to displace the fluorides from 4a with N,N-dimethylethylenediamine were unsuccessful. Analogue 4a on treatment with N-(t-butoxycarbonyl)ethylene diamine led to 15, formed from addition of the nucleophilic amine to C-3. On the other hand, analogue 4b, on treatment with N,N-dimethylethylenediamine led to the anticipated difluoride displacement product 3c. The protection of the hydroxy group of 4a by benzylation with phenyldiazomethane led to 4c which on treatment with N-(t-butoxycarbonyl)ethylene diamine or N,N-dimethylethylenediamine led to the corresponding 6,9-bis-substituted analogues 18a and 18b, respectively. Reductive debenzylations of 18a and 18b by hydrogenation over Pearlman's catalyst also effected partial reductions of the quinone. However, air oxidation of the over reduced products led to 3a and 3b, respectively. Treatment of 3a with hydrogen chloride gas led to the hydrochloride salt of 3d. Addition of O-p-Methoxybenzyl-N,N'-diisopropylurea to 4a led to the p-methoxybenzyl analogue 4d. Treatment of 4d with N,N-dimethylethylene diamine or N-(t-butoxycarbonyl)ethylene diamine led to displacements of the fluorides to yield 18c and 18d, respectively. Deprotection of 18c to 3b was accomplished using methanesulfonic acid. Treatment of 18d with trifluoroacetic acid followed by addition of maleic acid led to dimaleate salt of 3d.
- Krapcho,Maresch,Gallagher,Hacker,Menta,Oliva,Di Domenico,Da Re,Spinelli
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p. 1693 - 1702
(2007/10/03)
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