Vaida Milisiunaite

@ktu.lt

Faculty of Chemical Technology



           

https://researchid.co/vaida.mili

RESEARCH INTERESTS

organic synthesis

9

Scopus Publications

Scopus Publications

  • Synthesis of New Azetidine and Oxetane Amino Acid Derivatives through Aza-Michael Addition of NH-Heterocycles with Methyl 2-(Azetidin- or Oxetan-3-Ylidene)Acetates
    Emilis Gudelis, Sonata Krikštolaitytė, Monika Stančiauskaitė, Urtė Šachlevičiūtė, Aurimas Bieliauskas, Vaida Milišiūnaitė, Rokas Jankauskas, Neringa Kleizienė, Frank A. Sløk, and Algirdas Šačkus
    MDPI AG
    In this paper, a simple and efficient synthetic route for the preparation of new heterocyclic amino acid derivatives containing azetidine and oxetane rings was described. The starting (N-Boc-azetidin-3-ylidene)acetate was obtained from (N-Boc)azetidin-3-one by the DBU-catalysed Horner–Wadsworth–Emmons reaction, followed by aza-Michael addition with NH-heterocycles to yield the target functionalised 3-substituted 3-(acetoxymethyl)azetidines. Methyl 2-(oxetan-3-ylidene)acetate was obtained in a similar manner, which was further treated with various (N-Boc-cycloaminyl)amines to yield the target 3-substituted 3-(acetoxymethyl)oxetane compounds. The synthesis and diversification of novel heterocyclic amino acid derivatives were achieved through the Suzuki–Miyaura cross-coupling from the corresponding brominated pyrazole–azetidine hybrid with boronic acids. The structures of the novel heterocyclic compounds were confirmed via 1H-, 13C-, 15N-, and 19F-NMR spectroscopy, as well as HRMS investigations.

  • Synthesis and Characterization of Novel Heterocyclic Chalcones from 1-Phenyl-1H-pyrazol-3-ol
    Arminas Urbonavičius, Graziana Fortunato, Emilija Ambrazaitytė, Elena Plytninkienė, Aurimas Bieliauskas, Vaida Milišiūnaitė, Renzo Luisi, Eglė Arbačiauskienė, Sonata Krikštolaitytė, and Algirdas Šačkus
    MDPI AG
    An efficient synthetic route to construct diverse pyrazole-based chalcones from 1-phenyl-1H-pyrazol-3-ols bearing a formyl or acetyl group on the C4 position of pyrazole ring, employing a base-catalysed Claisen–Schmidt condensation reaction, is described. Isomeric chalcones were further reacted with N-hydroxy-4-toluenesulfonamide and regioselective formation of 3,5-disubstituted 1,2-oxazoles was established. The novel pyrazole-chalcones and 1,2-oxazoles were characterized by an in-depth analysis of NMR spectral data, which were obtained through a combination of standard and advanced NMR spectroscopy techniques.

  • Regioselective synthesis of methyl 5-(N-Boc-cycloaminyl)-1,2- oxazole-4-carboxylates as new amino acid-like building blocks
    Jolita Bruzgulienė, Greta Račkauskienė, Aurimas Bieliauskas, Vaida Milišiūnaitė, Miglė Dagilienė, Gita Matulevičiūtė, Vytas Martynaitis, Sonata Krikštolaitytė, Frank A Sløk, and Algirdas Šačkus
    Beilstein Institut
    A convenient and efficient synthesis of novel achiral and chiral heterocyclic amino acid-like building blocks was developed. Regioisomeric methyl 5-(N-Boc-cycloaminyl)-1,2-oxazole-4-carboxylates were prepared by the reaction of β-enamino ketoesters (including azetidine, pyrrolidine or piperidine enamines) with hydroxylamine hydrochloride. Unambiguous structural assignments were based on chiral HPLC analysis, 1H, 13C, and 15N NMR spectroscopy, HRMS, and single-crystal X-ray diffraction data.

  • Convenient synthesis of pyrazolo[4′,3′:5,6]pyrano[4,3-c][1,2]oxazoles via intramolecular nitrile oxide cycloaddition
    Vaida Milišiūnaitė, Elena Plytninkienė, Roberta Bakšienė, Aurimas Bieliauskas, Sonata Krikštolaitytė, Greta Račkauskienė, Eglė Arbačiauskienė, and Algirdas Šačkus
    MDPI AG
    A simple and efficient synthetic route to the novel 3a,4-dihydro-3H,7H- and 4H,7H-pyrazolo[4′,3′:5,6]pyrano[4,3-c][1,2]oxazole ring systems from 3-(prop-2-en-1-yloxy)- or 3-(prop-2-yn-1-yloxy)-1H-pyrazole-4-carbaldehyde oximes has been developed by employing the intramolecular nitrile oxide cycloaddition (INOC) reaction as the key step. The configuration of intermediate aldoximes was unambiguously determined using NOESY experimental data and comparison of the magnitudes of 1JCH coupling constants of the iminyl moiety, which were greater by approximately 13 Hz for the predominant syn isomer. The structures of the obtained heterocyclic products were confirmed by detailed 1H, 13C and 15N NMR spectroscopic experiments and HRMS measurements.

  • Synthesis and characterization of novel methyl (3)5-(n-boc-piperidinyl)-1h-pyrazole-4-carboxylates
    Gita Matulevičiūtė, Eglė Arbačiauskienė, Neringa Kleizienė, Vilija Kederienė, Greta Ragaitė, Miglė Dagilienė, Aurimas Bieliauskas, Vaida Milišiūnaitė, Frank A. Sløk, and Algirdas Šačkus
    MDPI AG
    Series of methyl 3- and 5-(N-Boc-piperidinyl)-1H-pyrazole-4-carboxylates were developed and regioselectively synthesized as novel heterocyclic amino acids in their N-Boc protected ester form for achiral and chiral building blocks. In the first stage of the synthesis, piperidine-4-carboxylic and (R)- and (S)-piperidine-3-carboxylic acids were converted to the corresponding β-keto esters, which were then treated with N,N-dimethylformamide dimethyl acetal. The subsequent reaction of β-enamine diketones with various N-mono-substituted hydrazines afforded the target 5-(N-Boc-piperidinyl)-1H-pyrazole-4-carboxylates as major products, and tautomeric NH-pyrazoles prepared from hydrazine hydrate were further N-alkylated with alkyl halides to give 3-(N-Boc-piperidinyl)-1H-pyrazole-4-carboxylates. The structures of the novel heterocyclic compounds were confirmed by 1H-, 13C-, and 15N-NMR spectroscopy and HRMS investigation.

  • Synthesis and anthelmintic activity of benzopyrano[2,3-c]pyrazol-4(2H)-one derivatives
    Vaida Milišiūnaitė, Alena Kadlecová, Asta Žukauskaitė, Karel Doležal, Miroslav Strnad, Jiří Voller, Eglė Arbačiauskienė, Wolfgang Holzer, and Algirdas Šačkus
    Springer Science and Business Media LLC

  • Synthesis of 2H-furo[2,3-c]pyrazole ring systems through silver(I) ion-mediated ring-closure reaction
    Vaida Milišiūnaitė, Rūta Paulavičiūtė, Eglė Arbačiauskienė, Vytas Martynaitis, Wolfgang Holzer, and Algirdas Šačkus
    Beilstein Institut
    Fused pyrazole ring systems are common structural motifs of numerous pharmaceutically important compounds. Nevertheless, access to derivatives of the aromatic 2H-furo[2,3-c]pyrazole ring system is still quite limited, and their chemistry and functional properties remain largely underexplored. The current study investigates routes to construct this system from easily accessible starting materials using metal-catalyzed reactions. A simple and efficient procedure to access the 2H-furo[2,3-c]pyrazole ring system was developed by employing the silver(I) ion-mediated ring-closure reaction of 4-alkynyl-3-hydroxy-1-phenyl-1H-pyrazoles as a key step. The required intermediate hydroxyalkynyl substrates for this reaction were prepared by a Pd-catalyzed coupling of 4-iodo-1-phenyl-1H-pyrazol-3-ol with ethyne derivatives. The structures of the obtained target compounds were unequivocally confirmed by detailed 1H, 13C and 15N NMR spectroscopic experiments, HRMS and a single-crystal X-ray diffraction analyses. This silver(I)-mediated 5-endo-dig cyclization of readily available 4-alkynyl-3-hydroxy-1H-pyrazoles can be used as an efficient method to access many novel 2,5-disubstituted 2H-furo[2,3-c]pyrazoles.

  • Synthesis and anti-mitotic activity of 2,4- or 2,6-disubstituted- and 2,4,6-trisubstituted-2H-pyrazolo[4,3-c]pyridines
    Vaida Milišiūnaitė, Eglė Arbačiauskienė, Eva Řezníčková, Radek Jorda, Veronika Malínková, Asta Žukauskaitė, Wolfgang Holzer, Algirdas Šačkus, and Vladimír Kryštof
    Elsevier BV