- Syntheses of Enantiopure 1,2-Ethylenediamines with Tethered Secondary Amines of the Formula H 2NCH 2CH[(CH 2) nNHMe]NH 2(n = 1-4) from α-Amino Acids: New Agents for Asymmetric Catalysis
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Tris(hydrochloride) adducts of the title compounds-are prepared from the inexpensive α-amino acids H 2 N(C=O)CH 2 CH(NH 2)CO 2 H, HO(C=O)(CH 2) n ′ CH(NH 2)CO 2 H (n ′ = 1, 2), and H2 N(CH 2) 4 CH(NH 2)CO 2 H, respectively (steps/overall yield = 5/32, 7/30, 7/33, 5/38). The NH 2 group that is remote from the secondary amine is installed via BH 3 reduction of an amide [-(C=O)NR 2[ derived?-from an α-amino carboxylic acid. The MeNHCH 2 units are introduced by BH 3 reductions of alkyl carbamate [RO(C=O)NHCH 2-; R = Et, t-Bu] or amide [MeHN(C=O)-] moieties.
- Kabes, Connor Q.,Gunn, Jack H.,Selbst, Maximilian A.,Lucas, Reagan F.,Gladysz, John A.
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p. 3277 - 3285
(2020/11/02)
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- Efficient Synthesis of a Family of Bifunctional Chelators Based on the PCTA[12] Macrocycle Suitable for Bioconjugation
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PCTA[12] is a 12-membered tetraaza-macrocyclic ligand that incorporates a pyridine unit within the macrocyclic ring and three acetate pendant arms. Unlike DOTA and NOTA chelators, PCTA is a recent entry to the field of macrocyclic polyaminocarboxylate ligands available to complex a variety of M2+/M3+ ions for biomedical applications such as diagnostic and radiotherapeutic. Despite the promising properties of its chelates, only a few of bifunctional chelating agents (BFCAs) derived from PCTA have been described so far. Based on our very recent methodology for the preparation of PCTA[12] itself, we report here the efficient synthesis of several BFCAs derived from PCTA bearing a free reactive function group, mainly devoted to conjugation purposes: ester, carboxylic acid, alcohol, aliphatic amine, aromatic amine, maleimide, bromo or azide functions. These functions were introduced either on the 4-position of the pyridine ring or on the methylene carbon atom of the central acetate chelating arm, while keeping the three carboxylate groups available for metal chelation. Moreover, two of these BFCAs-PCTA were used for conjugation with a tetrapeptide (cholecystokinin analogue), a bioactive molecule (biotin), or a solid support (silica gel).
- Leygue, Nadine,Enel, Morgane,Diallo, Abdel,Mestre-Voegtlé, Béatrice,Galaup, Chantal,Picard, Claude
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p. 2899 - 2913
(2019/05/15)
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- SERINE REPLACEMENT POLYMYXIN ANALOGUES USEFUL AS ANTIBIOTIC POTENTIATORS
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The disclosure provides compounds of the formula I or a tautomer thereof, or a pharmaceutically acceptable salt of either of the foregoing. The variables R1 and R2 are defined in the disclosure. The disclosure further includes pharmaceutical compositions comprising a compound of formula I together with at least one pharmaceutically acceptable carrier. The disclosure also includes a method of sensitizing bacteria to an antibacterial agent, comprising administering a therapeutically effective amount of the antibacterial agent and a compound of formula I to a patient infected with the bacteria, simultaneously or sequentially.
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Paragraph 0120
(2017/12/09)
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- Organomediated Enantioselective 18F Fluorination for PET Applications
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The first organomediated asymmetric 18F fluorination has been accomplished using a chiral imidazolidinone and [18F]N-fluorobenzenesulfonimide. The method provides access to enantioenriched 18F-labeled α-fluoroaldehydes (>90 % ee), which are versatile chiral 18F synthons for the synthesis of radiotracers. The utility of this process is demonstrated with the synthesis of the PET (positron emission tomography) tracer (2S,4S)-4-[18F]fluoroglutamic acid.
- Buckingham, Faye,Kirjavainen, Anna K.,Forsback, Sarita,Krzyczmonik, Anna,Keller, Thomas,Newington, Ian M.,Glaser, Matthias,Luthra, Sajinder K.,Solin, Olof,Gouverneur, Véronique
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supporting information
p. 13366 - 13369
(2015/11/09)
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- Diaminodiacid-based solid-phase synthesis of peptide disulfide bond mimics
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The antimicrobial peptide tachyplesin I was used as a model to apply the title strategy, which was developed for the preparation of peptidic macrocycles with double disulfide surrogates. The folding and activity of the tachyplesin I analogues were found to be sensitive to the structure of the disulfide surrogates, thus underlining the necessity of a flexible synthetic route for generating disulfide bond surrogates with high structural diversity. Copyright
- Cui, Hong-Kui,Guo, Ye,He, Yao,Wang, Feng-Liang,Chang, Hao-Nan,Wang, Yu-Jia,Wu, Fang-Ming,Tian, Chang-Lin,Liu, Lei
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supporting information
p. 9558 - 9562
(2013/09/23)
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- Inhibition of glyoxalase I: The first low-nanomolar tight-binding inhibitors
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A series of rational modifications to the structure of known S-(N-aryl-N-hydroxycarbamoyl)glutathione-based glyoxalase I inhibitors culminated in the discovery of the first single-digit nanomolar inhibitor. This study makes available key information about possible means to address the issues of metabolic instability, low potency, and synthetic complexicity that have plagued the area of glyoxalase I inhibition. Knowledge garnered from this study has implications in the design of inhibitors with higher conformational definition and lower peptidic character.
- More, Swati S.,Vince, Robert
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supporting information; experimental part
p. 4650 - 4656
(2010/03/01)
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- The Synthesis of the High-Potency Sweetener, NC-00637. Part 3: The Glutamyl Moiety and Coupling Reactions
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The synthesis of the high-potency sweetener, NC-00637 (1), required selective preparation of the γ-protected glutamic acid. Coupling of the three components could be performed in any order, but the final route involved N-acylation of the protected L-glutamic acid with the acid chloride derived from (S)-2-methylhexanoic acid. Activation of the α-carboxyl group allowed condensation with 5-amino-2-cyanopyridine (4). Saponification of the γ-ester 19 then provided the sweetener 1.
- Ager, David J.,Babler, Scott,Erickson, Robert A.,Froen, Diane E.,Kittleson, Jeannine,Pantaleone, David P.,Prakash, Indra,Zhi, Ben
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- SYNTHESIS OF NONPROTEINOGENIC AMINO ACIDS PART 2: PREPARATION OF A SYNTHETIC EQUIVALENT OF THE γ-ANION SYNTHON FOR ASYMMETRIC AMINO ACID SYNTHESIS
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The synthesis of α-t-butyl γ-methyl N-trityl-(S)-glutamate (12) from (S)-glutamic acid (6) is described.Diester (12), on treatment with lithium isopropylcyclohexylamide followed by the addition of carbonyl compounds, reacts to give the γ-substituted glutamic acid derivatives (13a-i) with retention of optical purity at the α centre.
- Baldwin, Jack E.,North, Michael,Flinn, Anthony,Moloney, Mark G.
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p. 1453 - 1464
(2007/10/02)
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