202187-27-7Relevant articles and documents
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.
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.
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