- Aminoglycoside hybrids as potent RNA antagonists
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Aminoglycosides specifically bind to the A-site decoding region of prokaryotic 16S rRNA with dissociation constants in the 1-2 μM range. The aminoglycoside paromomycin binds to a truncated A-site construct with a K(d) = 1.85 μM. Paromomycin analogs are described here in which the aminoglycoside is linked via spacer groups to either thiazole orange or pyrene. These analogs bind specifically to the truncated A-site construct, but with affinities considerably higher than paromomycin itself. The binding of the hybrid molecules to the A-site is greater the shorter the spacer group.
- Tok, Jeffrey B.-H.,Cho, Junhyeong,Rando, Robert R.
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Read Online
- Dual function catalysts. Dehydrogenation and asymmetric intramolecular Diels-Alder cycloaddition of N-hydroxy formate esters and hydroxamic acids: Evidence for a ruthenium-acylnitroso intermediate
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The chiral ruthenium salen complex, 13b, functions as an efficient catalyst for the sequential oxidation and asymmetric Diels-Alder cycloaddition of hydroxamic acids and N-hydroxy formate esters. This result provides evidence for the formation of a ruthen
- Chow, Chun P.,Shea, Kenneth J.
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Read Online
- PRODUCTION METHOD OF IODOALKANE DERIVATIVE USING MICROWAVE
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PROBLEM TO BE SOLVED: To provide a production method of an iodoalkane derivative, with which the iodoalkane derivative can be produced even in a nonpolar solvent. SOLUTION: In a production method of a 5-iodovaleric acid ester, for example a 5-halogenovaleric acid ester represented by formula (1A) (in formula, R is a 1-6C alkyl group or a 7-11C aralkyl group and X is a chlorine atom or a bromine atom), is made to react with an alkali metal iodide salt by being brought into contact therewith in an organic solvent, in the presence of a tetrasubstituted ammonium salt, and further under microwave irradiation, in which 5-iodovaleric acid ester is represented by formula (3A), (in formula, R is synonymous with that in formula (1A)). SELECTED DRAWING: None COPYRIGHT: (C)2021,JPOandINPIT
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Paragraph 0074-0078
(2021/07/27)
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- Finkelstein Reaction in Non-polar Organic Solvents: A Streamlined Synthesis of Organic Iodides
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The Finkelstein reaction of organic halides was found to proceed smoothly in non-polar organic solvents other than acetone when operated in the presence of a catalytic amount of tetra-n-butylammonium bromide and water. The new protocol was successfully applied to a preparation of ethyl 5-iodopentanoate from the corresponding bromide which was used directly for zinc reagent formation and Fukuyama coupling to enable the formation of the (+)-biotin side chain in a streamlined manner. Rate acceleration by microwave irradiation and an application to the synthesis of trimethylsilyl iodide will be described as well.
- Takahashi, Yusuke,Seki, Masahiko
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p. 1974 - 1978
(2021/08/24)
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- Modulation of BCR signaling by the induced dimerization of receptor-associated SYK
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Clustering of the B cell antigen receptor (BCR) by polyvalent antigens is transmitted through the SYK tyrosine kinase to the activation of multiple intracellular pathways that determine the physiological consequences of receptor engagement. To explore factors that modulate the quantity and quality of signals sent by the crosslinked BCR, we developed a novel chemical mediator of dimerization to induce clustering of receptor-associated SYK. To accomplish this, we fused SYK with E. coli dihydrofolate reductase (eDHFR), which binds the small molecule trimethoprim (TMP) with high affinity and selectivity and synthesized a dimer of TMP with a flexible linker. The TMP dimer is able to induce the aggregation of eDHFR-linked SYK in live cells. The induced dimerization of SYK bound to the BCR differentially regulates the activation of downstream transcription factors, promoting the activation of Nuclear Factor of Activated T cells (NFAT) without affecting the activation of NFκB. The dimerization of SYK enhances the duration but not the amplitude of calcium mobilization by enhancing the extent and duration of its interaction with the crosslinked BCR at the plasma membrane.
- Westbroek, Mark L.,Geahlen, Robert L.
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- The value of 2JP–CO as a diagnostic parameter for the structure and thermal reactivity of carbonyl-stabilised phosphonium ylides
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A survey of 20 carbonyl-stabilised phosphonium ylides with recently reported X-ray structures shows a strong correlation between the C[dbnd]P to C[dbnd]O torsion angle and the value of 2JP–CO, with high values being associated with an anti configuration and low with syn. Seven new X-ray structural determinations are reported, several for types of ylide not crystallographically characterised before, and these also conform to this pattern. The value of 2JP–CO is then correlated with whether or not thermal extrusion of Ph3PO occurs to give alkynes for over 200 ylides and an empirical rule developed that the extrusion never occurs for ylides where this value is > 11 Hz. This is used to rationalise the anomalous behaviour of some trioxo ylides and cyclic ylides, two of which afford cycloalkynes, isolated after rearrangement as the isomeric 1,3-dienes. The rule also holds for a family of novel highly fluorinated ylides which afford fluorinated alkynes in good yield upon flash vacuum pyrolysis.
- Aitken, R. Alan,Boubalouta, Youcef,Chang, Da,Cleghorn, Lee P.,Gray, Ian P.,Karodia, Nazira,Reid, Euan J.,Slawin, Alexandra M.Z.
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p. 6275 - 6285
(2017/09/29)
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- Synthesis of Non-natural, Frame-Shifted Isoprenoid Diphosphate Analogues
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A set of synthetic approaches was developed and applied to the synthesis of eight frame-shifted isoprenoid diphosphate analogues. These analogues were designed to increase or decrease the methylene units between the double bonds and/or the pyrophosphate m
- Temple, Kayla J.,Wright, Elia N.,Fierke, Carol A.,Gibbs, Richard A.
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supporting information
p. 6038 - 6041
(2016/12/09)
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- Ligand-Enabled Meta-C-H Alkylation and Arylation Using a Modified Norbornene
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2-Carbomethoxynorbornene is identified as a more effective transient mediator to promote a Pd(II)-catalyzed meta-C(sp2)-H alkylation of amides with various alkyl iodides as well as arylation with previously incompatible aryl iodides. The use of a tailor-made quinoline ligand is also crucial for this reaction to proceed.
- Shen, Peng-Xiang,Wang, Xiao-Chen,Wang, Peng,Zhu, Ru-Yi,Yu, Jin-Quan
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supporting information
p. 11574 - 11577
(2015/09/28)
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- Enantioselective allylic hydroxylation of w-alkenoic acids and esters by P450 BM3 monooxygenase
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Chiral allylic alcohols of w-alkenoic acids and derivatives thereof are highly important building blocks for the synthesis of biologically active compounds. The direct enantioselective C-H oxidation of linear terminal olefins offers the shortest route toward these compounds, but known synthetic methods are limited and suffer from low selectivities. Described herein is an enzymatic approach using the P450 BM3 monooxygenase mutant A74G/L188Q, which catalyzes allylic hydroxylation with high to excellent chemo- and enantioselectivities providing the desirable secondary alcohols.
- Neufeld, Katharina,Henssen, Birgit,Pietruszka, J?rg
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supporting information
p. 13253 - 13257
(2015/02/19)
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- BRANCHED ALKYL AND CYCLOALKYL TERMINATED BIODEGRADABLE LIPIDS FOR THE DELIVERY OF ACTIVE AGENTS
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The present invention relates to a cationic lipid of formula (I) having one or more biodegradable groups located in a lipidic moiety (e.g., a hydrophobic chain) of the cationic lipid. These cationic lipids may be incorporated into a lipid particle for delivering an active agent, such as a nucleic acid. The invention also relates to lipid particles comprising a neutral lipid, a lipid capable of reducing aggregation, a cationic lipid of the present invention, and optionally, a sterol. The lipid particle may further include a therapeutic agent such as a nucleic acid.
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Page/Page column 56
(2013/06/27)
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- Type 2 intramolecular N-acylazo Diels-Alder reaction: Regio- and stereoselective synthesis of bridgehead bicyclic 1,2-diazines
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(Chemical Equation Presented) The type 2 intramolecular N-acylazo Diels-Alder reaction provides a regio- and stereoselective synthesis of bicyclic 1,2-diazine systems. A new method for the generation of N-acylazo dienophiles with tetra-n-butylammonium periodate is reported. X-ray crystallographic analysis allowed the quantification of structural distortions of the nonplanar bridgehead olefin and lactam functionalities in 1,2-diazine cycloadducts 11 and 15. Caprolactams and enantholactams were formed by stereoselective bridgehead alkene reduction, a process that transfers stereochemistry from the bridgehead lactam nitrogen to the bridgehead carbon. The sequence of transformations offers a convenient route for the diastereoselective synthesis of medium-ring nitrogen heterocycles and 1,4-diamines.
- Molina, Claudia L.,Chow, Chun P.,Shea, Kenneth J.
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p. 6816 - 6823
(2008/02/10)
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- Intramolecular palladium(II)-catalyzed 1,2-addition to allenes
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Palladium(II)-catalyzed intramolecular 1,2-additions to allenes substituted with an internal nucleophile have been developed. Carboxylic acids, alcohols, N-substituted amides, and carbamates were used as internal nucleophiles in the palladium-catalyzed re
- Jonasson,Horvath,Backvall
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p. 9600 - 9609
(2007/10/03)
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- Facile synthesis of (+)-biotin via Fukuyama coupling reaction
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Treatment of a thiolactone 2 with a zinc reagent 3 in the presence of PdCl2(PPh3)2 (10 mol%) allowed installation of a C-2 side chain of (+)- biotin in a highly efficient manner, which enabled synthesis of (+)biotin in three steps from 2. (C) 2000 Elsevier Science Ltd.
- Shimizu, Toshiaki,Seki, Masahiko
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p. 5099 - 5101
(2007/10/03)
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- One-step cross-coupling reaction of functionalized alkyl iodides with aryl halides by the use of an electrochemical method
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Organozinc compounds of functionalized alkyl iodide carrying an alkoxycarbonyl, cyano or alkenyl group were prepared in high yields under mild conditions (0°C-r.t., 10min in DMF) by the reaction of iodides with an electrogenerated reactive zinc (EGZn). Cross-coupling of the organozinc compounds with various aryl halides in the presence of 5 mol% Pd(P(o- Tol)3)2Cl2 in THF gave the corresponding cross-coupled products in moderate to high yields. These cross-coupling reactions can be also achieved in one step and in one pot by the use of an electrochemical method utilizing a Pt cathode and Zn anode.
- Kurono, Nobuhito,Sugita, Kazuya,Takasugi, Shingo,Tokuda, Masao
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p. 6097 - 6108
(2007/10/03)
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- The synthesis of the vitamers of biotin
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An efficient synthetic pathway for the preparation of the vitamers of biotin which provides easy access to optically pure KAPA as well as diastereomeric mixtures of DAPA, DTB, and analogs thereof has been developed.
- Nudelman, Abraham,Nudelman, Ayelet,Marcovici-Mizrahi, Dana,Flint, Dennis
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p. 157 - 168
(2007/10/03)
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- Efficient Syntheses of the OPC Homologous Series, OPC-1:0, -3:0, -4:0, -5:0, -6:0, -7:0, and -8:0
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The OPC homologous series was synthesized from 2-[(Z)-2-pentenyl]cyclopenten-1-one in short steps and with high yields. The carbon-carbon bond formation was achieved by the 1,4-conjugate addition approach. This method makes it possible to supply a suffici
- Toshima, Hiroaki,Nara, Shinji,Aramaki, Hisateru,Ichihara, Akitami,Koda, Yasunori,Kikuta, Yoshio
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p. 1724 - 1728
(2007/10/03)
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- A CONVENIENT PREPARATION OF IODOALKYL ESTERS FROM LACTONES
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The reaction of lactones with trimethylsilyl iodide in the presence of an alcohol provides a short and convenient access to iodoalkyl esters, useful intermediates in organic synthesis.
- Kolb, Michael,Barth, Jacqueline
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p. 763 - 768
(2007/10/02)
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- SN2 iodide displacement on unsymmetrical cyclic dioxenium salts. A stereoelectronically controlled reaction
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Iodide ion reacts with the cyclic dioxenium salts 1-6 to yield mixtures of iodoester and lactone plus alkyl iodide (Table 1).The formation of iodoester competing with the formation of lactone appears to be an unexpected result.It can, however, be explained by a stereoelectronic effect, similar to the anomeric effect in acetals, which is also responsible for the greater stability of the Z over the E form in dioxenium salts and in esters.
- Beaulieu, Normand,Deslongchamps, Pierre
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p. 164 - 167
(2007/10/02)
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- Cyclopentane derivatives manufacture
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The present invention relates to new cyclopentane derivatives having the formula STR1 and to a process for their manufacture. The compounds can be used as medicaments due to their antiprostaglandin effect.
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- Synthesis of some monothienylalkyl esters of aliphatic dicarboxylic acids
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1. A. new method was developed for the synthesis of the half-esters of dicarboxylic acids. 2. Some members of the acid esters of acidophobic alcohols were synthesized, and specifically the mono-3-(2-thienyl)propyl ester of adipic acid and the mono-2-(2-thienyl)ethyl ester of pimelic acid.
- Taits,Dudinov,Alashev,Gol'dfarb
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p. 138 - 141
(2007/10/05)
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