202187-27-7Relevant academic research and scientific papers
Synthesis of novel N-heterocyclic compounds containing 1,2,3-triazole ring system via domino, “click” and RDA reactions
Palkó, Márta,Haimer, Mohamed El,Kormányos, Zsanett,Fül?p, Ferenc
, (2019/02/26)
An uncomplicated, high-yielding synthetic route has been developed to constitute complicated heterocycles, applying domino, click and retro-Diels–Alder (RDA) reaction sequences. Starting from 2-aminocarboxamides, a new set of isoindolo[2,1-a]quinazolinones was synthesized with domino ring closure. A click reaction was performed to create the 1,2,3-triazole heterocyclic ring, followed by an RDA reaction resulting in dihydropyrimido[2,1-a]isoindole-2,6-diones. The absolute configuration, concluded by the norbornene structure that served as a chiral source, remained constant throughout the transformations. The structure of the synthesized compounds was examined by1H and13C Nuclear Magnetic Resonance (NMR) methods.
Flow-chemistry enabled efficient synthesis of β-peptides: Backbone topology: Vs. helix formation
Nekkaa, Imane,Bogdán, Dóra,Gáti, Tamás,Béni, Szabolcs,Juhász, Tünde,Palkó, Márta,Paragi, Gábor,Tóth, Gábor K.,Fül?p, Ferenc,Mándity, István M.
, p. 3061 - 3064 (2019/04/06)
Enantiodiscriminative helix formation was observed for β-peptide H14 helices. This observation is caused by the synperiplanar orientation of H-O atoms which is more unfavorable than those for H-H interaction. The 1,2 H-O interaction leads to the destructi
The N-Hydroxymethyl Group as a Traceless Activating Group for the CAL-B-Catalysed Ring Cleavage of β-Lactams: A Type of Two-Step Cascade Reaction
Forró, Enik?,Galla, Zsolt,Fül?p, Ferenc
, p. 2647 - 2652 (2016/06/09)
An efficient enzymatic two-step cascade procedure has been devised for rapid access to diverse amino acids from N-hydroxymethyl-β-lactams; representative amino acids include the antifungal agent cispentacin, intermediates for the taxol side-chain, and assorted cathepsin inhibitors. When CAL-B-catalysed hydrolyses of racemic N-hydroxymethyl-β-lactams were performed with H2O (0.5 equiv.) in iPr2O at 60 °C, relatively quick (vs. non-activated counterparts) and enantioselective (E > 200) ring cleavage reactions took place. As the ring-opened amino acids formed, the hydroxymethyl group, as a traceless activating group, underwent spontaneous in situ degradation. Consequently, the desired β-amino acid and unreacted N-hydroxymethyl-β-lactam enantiomers (ee > 95 %) were formed. The formation of polymers, induced by liberation of formaldehyde, was successfully restricted by the addition of benzylamine as a capture agent, to the enzymatic reactions. An efficient enzymatic two-step cascade procedure was devised for CAL-B-catalysed hydrolysis of racemic N-hydroxymethyl-β-lactams. Conditions in which the hydroxymethyl group serves as a traceless activating group (E > 200), giving desired β-amino acid along with unreacted starting lactam enantiomers (ee > 95 %) were identified; polymerization was controlled by addition benzylamine addition.
Stereocontrolled one-step synthesis of difunctionalised cispentacin derivatives through ring-opening metathesis of norbornene β-amino acids
Kiss, Lornd,Kardos, Mrton,Forr, Eniko,Fül?p, Ferenc
, p. 1283 - 1289 (2015/03/04)
Through the ring-opening metathesis of norbornene or oxanorbornene β-amino acids with ethylene in the presence of certain Ru catalysts, a facile and convenient stereocontrolled one-step method was devised for the preparation of divinylated cispentacins an
A new access route to functionalized cispentacins from norbornene β-amino acids
Kiss, Loránd,Cherepanova, Maria,Forró, Eniko,Fül?p, Ferenc
, p. 2102 - 2107 (2013/03/28)
An efficient and simple new stereocontrolled access route to novel disubstituted cispentacin derivatives with multiple stereogenic centers from norbornene β-lactam has been developed. The synthesis involves olefinic bond functionalization by dihydroxylation followed by oxidative ring cleavage and transformation of the dialdehyde intermediate through a Wittig reaction. Copyright
Enantiomeric discrimination of cyclic β-amino acids using (18-crown-6)-2,3,11,12-tetracarboxylic acid as a chiral NMR solvating agent
Chisholm, Cora D.,Fueloep, Ferenc,Forro, Eniko,Wenzel, Thomas J.
experimental part, p. 2289 - 2294 (2010/11/05)
(18-Crown-6)-2,3,11,12-tetracarboxylic acid is an excellent chiral NMR solvating agent for cyclic β-amino acids with cyclopentane, cyclohexane, cycloheptane, cyclopentene, cyclohexene, bicyclo[2.2.1]heptane, and bicyclo[2.2.1]heptene rings. The crown ether was added to the neutral β-amino acids in methanol-d4. A neutralization reaction between the crown ether and β-amino acid forms the ammonium ion needed for favorable association. Enantiomeric discrimination of the two hydrogen atoms α to the amine and carboxylic acid moieties of the β-amino acid was observed with every substrate studied. Trends in the order of the enantiomeric discrimination of certain hydrogen atoms for substrates of similar structures correlate with the absolute configuration.
Vapour-assisted enzymatic hydrolysis of β-lactams in a solvent-free system
Forro, Eniko,Fueloep, Ferenc
, p. 1005 - 1009 (2008/09/21)
A new, solvent-free, vapour-assisted method, developed for the synthesis of carbocyclic cis β-amino acid enantiomers through the Candida antarctica lipase B-catalysed enantioselective (E >200) hydrolysis of β-lactams with 0.5 equiv of H2O at 70 °C, has been demonstrated to be applicable on a preparative scale to produce (±)-2 (the starting racemate for cispentacin), (±)-3 (the starting racemate for 4-tert-butylcispentacin, a new cispentacin analogue) and (±)-7 (the starting racemate for 1,4-ethylene-bridged cispentacin).
Oligomers of cis-β-norbornene amino acid: Formation of β-strand mimetics
Chandrasekhar, Srivari,Babu, Bathini Nagendra,Prabhakar, Anabathula,Sudhakar, Ambadi,Reddy, Marepally Srinivasa,Kiran, Marelli Udaya,Jagadeesh, Bharatam
, p. 1548 - 1550 (2008/03/12)
The oligomers of constrained cis-exo-β-norbornene amino acid were synthesised and characterised by extensive NMR, CD, IR and MD studies. The results showed the formation of both right and left handed consecutive 6-membered hydrogen-bonded strands for [2S,
Synthesis of enantiopure 1,4-ethyl- and 1,4-ethylene-bridged cispentacin by lipase-catalyzed enantioselective ring opening of β-lactams
Forro, Eniko,Fueloep, Ferenc
, p. 573 - 575 (2007/10/03)
1,4-Ethyl- and 1,4-ethylene-bridged cispentacin enantiomers 1a, 1c and 2a, 2c were prepared through the lipase-catalyzed enantioselective ring opening of racemic exo-3-azatricyclo[4.2.1.02.5]nonan-4-one, (±)-1, and exo-3-azatricyclo[4.2.1.02.5]non-7-en-4-one, (±)-2. High enantioselectivity (E >200) was observed when the Lipolase-catalyzed reactions were performed with 1equiv of H2O in diisopropyl ether at 70°C. The resolved β-amino acids 1a and 2a (yield 46%) and β-lactams 1b and 2b (yield≥40%) could be easily separated. The ring opening of lactam enantiomers with 18% HCl afforded the corresponding β-amino acid hydrochloride enantiomers (ee ≥98%).
Use of hydrolases for the synthesis of cyclic amino acids
Lloyd, Richard C.,Lloyd, Michael C.,Smith, Mark E. B.,Holt, Karen E.,Swift, Jonathan P.,Keene, Philip A.,Taylor, Stephen J. C.,McCague, Raymond
, p. 717 - 728 (2007/10/03)
The synthesis of several cyclic amino acids that have all the necessary structural features to make them ideal scaffolds for use in medicinal chemistry is described. A key step in each synthesis is the use of hydrolase enzymes to define a chiral centre. I
