1685-33-2Relevant articles and documents
Zinc-mediated carbon radical addition to glyoxylic imines in aqueous media for the synthesis of α-amino acids
Ueda, Masafumi,Miyabe, Hideto,Sugino, Hisako,Naito, Takeaki
, p. 1124 - 1128 (2005)
The addition of carbon radicals to glyoxylic imines was studied using zinc dust as a radical initiator. The zinc-mediated radical reaction of glyoxylic oxime ethers and hydrazones proceeded smoothly to give the alkylated products via a carbon-carbon bond-
Synthesis and solid-phase application of suitably protected γ-hydroxyvaline building blocks
Cudic, Mare,Mari, Frank,Fields, Gregg B.
, p. 5581 - 5586 (2007)
(Chemical Equation Presented) Recently, an unexpected modified residue, γ-hydroxy-D-valine (D-Hyv), was identified within ribosomally expressed polypeptide chains of four conopeptides from the venoms of Conus gladiator and Conus mus. To assemble Hyv-conta
Design and synthesis of novel symmetric fluorene-2,7-diamine derivatives as potent hepatitis C virus inhibitors
Mousa, Mai H. A.,Ahmed, Nermin S.,Schwedtmann, Kai,Frakolaki, Efseveia,Vassilaki, Niki,Zoidis, Grigoris,Weigand, Jan J.,Abadi, Ashraf H.
, (2021/04/16)
Hepatitis C virus (HCV) is an international challenge. Since the discovery of NS5A direct-acting antivirals, researchers turned their attention to pursue novel NS5A inhibitors with optimized design and structure. Herein we explore highly potent hepatitis C virus (HCV) NS5A inhibitors; the novel analogs share a common symmetrical prolinamide 2,7-diaminofluorene scaffold. Modification of the 2,7-diaminofluorene backbone included the use of (S)-prolinamide or its isostere (S,R)-piperidine-3-caboxamide, both bearing different amino acid residues with terminal carbamate groups. Compound 26 exhibited potent inhibitory activity against HCV genotype (GT) 1b (effective concentration (EC50) = 36 pM and a selectivity index of >2.78 × 106). Compound 26 showed high selectivity on GT 1b versus GT 4a. Interestingly, it showed a significant antiviral effect against GT 3a (EC50 = 1.2 nM). The structure-activity relationship (SAR) analysis revealed that picomolar inhibitory activity was attained with the use of S-prolinamide capped with R- isoleucine or R-phenylglycine residues bearing a terminal alkyl carbamate group.
Enantioselective inclusion of pyrene-1-sulfonate salts of α-amino acids with crystals of α-cyclodextrin
Hattori, Tetsutaro,Kitamoto, Yuichi,Maeda, Tetsuya,Miyoshi, Ikuko,Morohashi, Naoya
supporting information, (2020/04/01)
Enantioselective inclusion of α-amino acids with crystals of α-cyclodextrin (α-CD) has been achieved by converting the amino acids into sulfonate salts with pyrene-1-sulfonic acid (PyS). For example, crystals of α-CD selectively include L-leucine/PyS (1:1) salt in a host/guest ratio of ～1 with 92%ee from a solution of the racemic salt in ethanol/N-methylformamide (91:9) at 40 °C. Under conditions optimized for individual amino acids, the PyS salts of valine, phenylalanine, and methionine are also included with good enantioselectivities (up to 86%ee). Mechanistic studies for the inclusion of leucine/PyS salt reveals that the enantioselectivity originates from the difference in stability between the inclusion complexes of D- and L-leucine/PyS salts with α-CD in crystals.
Chiral tetraaryl-and tetraalkynylborates as chiral solvating agents for tetraalkylammonium salts
Tayama, Eiji,Sugawara, Takeshi
, p. 803 - 811 (2019/01/18)
The application of tetracarbon-substituted chiral borate sodium salts (NaBR*4) as NMR chiral solvating agents for various tetraalkylammonium salts (R4NX) has been successfully demonstrated. Ion exchange between R4NX and NaBR*4 proceeded in excellent yields and provided the corresponding dia-stereomeric salts (R4NBR*4). The ee values of the R4NX salts were determined by1H NMR analysis of R4NBR*4. Two types of chiral borates, tetraaryl-and tetraalkynylborates with optically active 1,1′-binaphthyl components were used. At the beginning of this research, we investigated the efficacy of a known chiral tetraar-ylborate developed by Pommerening et al. for R4NX. To expand the possibility of further structural design of the chiral borate, we designed chiral tetraalkynylborates as a new structure. Their synthesis and application are also described.
Expanding the chemical space of anti-HCV NS5A inhibitors by stereochemical exchange and peptidomimetic approaches
Ramsis, Triveena M.,Abdel Karim, Shereen E.,Vassilaki, Niki,Frakolaki, Efseveia,Kamal, Ahmed A. M.,Zoidis, Grigoris,Ahmed, Nermin S.,Abadi, Ashraf H.
, (2018/05/30)
Here we report a series of potent anti-HCV agents bearing a symmetrical benzidine l-prolinamide backbone with different capping groups including alkyl/aryl carbamates of natural and unnatural valine and leucine amino acids. All compounds were investigated for their inhibitory activity in an HCV replicon assay on genotype 1b. The novel compounds share some chemical and clinical attributes of commercially available NS5A inhibitors. Compounds 5 and 6 with unnatural capping residue and ethyl and isobutyl carbamates showed EC50 values in the picomolar range with a low toxicity profile and selectivity indices of several orders of magnitude. These findings enlarge the chemical space from which NS5A inhibitors may be discovered by adopting unnatural amino acids, amino acids other than valine and carbamates other than methyl as the capping groups.
HETEROCYCLIC UREA DERIVATIVES AND METHODS OF USE THEREOF
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Page/Page column 92, (2010/12/29)
Compounds of formula (IA) and their pharmaceutically acceptable salts are described. Processes for their preparation, pharmaceutical compositions containing them, their use as medicaments and their use in the treatment of bacterial infections are also described.
A bismuth(III)-catalyzed friedel-crafts cyclization and stereocontrolled organocatalytic approach to (-)-platensimycin
Eey, Stanley T.-C.,Lear, Martin J.
supporting information; experimental part, p. 5510 - 5513 (2011/03/18)
A high yielding route to the (-)-platensimycin core is communicated. This entailed the discovery of Bi(OTf)3 to catalyze a Friedel-Crafts cyclization of a free lactol, supplemented by LiClO4 to suppress the Lewis basicity of the sulfonate group. After TBAF-promoted cyclodearomatization, a diastereoselective conjugate reduction of a dienone was achieved by adopting amine-based organocatalytic rationales to reverse the inherent steric control of the substrate.
Synthesis and structure-activity relationship of a novel series of heterocyclic sulfonamide γ-secretase inhibitors
Pu, Jun,Kreft, Anthony F.,Aschmies, Suzan H.,Atchison, Kevin P.,Berkowitz, Joshua,Caggiano, Thomas J.,Chlenov, Micheal,Diamantidis, George,Harrison, Boyd L.,Hu, Yun,Huryn, Donna,Steven Jacobsen,Jin, Mei,Lipinski, Kerri,Lu, Peimin,Martone, Robert L.,Morris, Koi,Sonnenberg-Reines, June,Riddell, Dave R.,Sabalski, Joan,Sun, Shaiu-Ching,Wagner, Erik,Wang, Yiqun,Xu, Zheng,Zhou, Hua,Resnick, Lynn
experimental part, p. 4708 - 4717 (2009/10/23)
γ-Secretase inhibitors have been shown to reduce the production of β-amyloid, a component of the plaques that are found in brains of patients with Alzheimer's disease. A novel series of heterocyclic sulfonamide γ-secretase inhibitors that reduce β-amyloid levels in cells is reported. Several examples of compounds within this series demonstrate a higher propensity to inhibit the processing of amyloid precursor protein compared to Notch, an alternative γ-secretase substrate.
A Stereoselective entry into functionalized 1,2-diamines by zinc-mediated homologation of α-aminoacids
Hoang, Cam Thuy,Alezra, Valerie,Guillot, Regis,Kouklovsky, Cyrille
, p. 2521 - 2524 (2008/02/05)
A general, stereoselective synthsis of 4,5-disubstituted imidazolidines-2-ones from α-aminoacids has been developed: the key steps are a Biaise reaction of bromoacetate on α-aminonitriles and further reduction. Although reduction with sodium cyanoborohydride afforded a mixture of cis and trans isomers 6a-e with moderate to good stereoselectivity, reduction with sodium in liquid ammonia gave the trans isomers 8a-e with complete stereoselectivity. Acidic hydrolysis of the urea gave 4-amino-pyrrolidinones, which can be precursors to β,γ-diaminoacids or 3-aminopyrrolidines.
