401647-91-4Relevant academic research and scientific papers
Synthesis of novel 14-membered cyclic bis-semicarbazones
Shutalev, Anatoly D.,Fesenko, Anastasia A.,Kuzmina, Olesya M.,Volov, Alexander N.,Albov, Dmitry V.,Chernyshev, Vladimir V.,Zamilatskov, Ilia A.
, p. 5481 - 5485 (2014)
An efficient method for the stereoselective synthesis of novel 14-membered cyclic bis-semicarbazones based on acid-catalyzed cyclization of the hydrazones of 3-(3-oxobutyl)semicarbazides has been developed. The starting semicarbazides were prepared according to a four-step strategy involving amidoalkylation of the sodium enolate of acetylacetone with N-(α-tosylbenzyl)carbamates followed by base-promoted retro-Claisen reaction and treatment of the obtained N-(3-oxobutyl)carbamates with hydrazine.
Nickel(II), Copper(II) and Palladium(II) Complexes with Bis-Semicarbazide Hexaazamacrocycles: Redox-Noninnocent Behavior and Catalytic Activity in Oxidation and C-C Coupling Reactions
Arion, Vladimir B.,Breza, Martin,Darvasiová, Denisa,Dobrov, Anatolie,Fesenko, Anastasia,Martins, Luísa M. D. R. S.,Pombeiro, Armando J. L.,Rapta, Peter,Shutalev, Anatoly,Stepanenko, Iryna,Yankov, Alexander
, (2020/08/05)
Nickel(II), copper(II), and palladium(II) complexes MLH, where M = Ni (1), Cu (2), Pd (3), and MLOMe, where M = Ni (4), Cu (5), Pd (6), have been prepared by reactions of NiCl2·6H2O, Cu(OAc)2·H2O, and PdCl2(MeCN)2 with 14-membered bis-semicarbazide hexaazamacrocycles H2LH and H2LOMe in dimethylformamide (DMF). The compounds were characterized by elemental analysis, ESI mass spectrometry, IR, UV-vis, and 1D (1H, 13C) and 2D (1H-1H COSY, 1H-1H TOCSY, 1H-1H NOESY, 1H-13C HSQC, 1H-13C HMBC) NMR spectra (1, 3, 4, and 6), and X-ray diffraction (2, 4-6). The complexes with MIIN4 coordination environment have S = 0, 1/2, 0 ground states for Ni, Cu, and Pd, respectively. The electrochemical behavior of 1-6 was investigated in detail. The electronic structures of 1e-oxidized species were studied by EPR, UV-vis-NIR spectroelectrochemistry, and DFT calculations, indicating the redox-noninnocent behavior of the ligands. Compounds 1-6 were tested in the oxidation of styrene and C-C coupling (Henry and Knoevenagel condensations). Compounds 2 and 5 selectively catalyze the microwave-assisted oxidation of neat styrene to benzaldehyde (up to 88% yield), whereas the 1 and 4 catalytic systems afforded up to 99% β-nitroethanol yield with an appreciable diastereoselectivity toward the formation of the anti isomer.
Different modes of acid-catalyzed cyclization of 4-(γ-oxoalkyl)semicarbazide hydrazones: 7-membered versus 14-membered cyclic semicarbazones formation
Fesenko, Anastasia A.,Shutalev, Anatoly D.
, p. 9528 - 9543 (2015/12/05)
Acid-catalyzed cyclization of 4-(γ-oxoalkyl)semicarbazide hydrazones has been studied. 7-Membered cyclic semicarbazones, 2,4,5,6-tetrahydro-3H-1,2,4-triazepin-3-ones, were obtained from the γ-phenyl-substituted semicarbazides, while the cyclization of the γ-methyl-substituted semicarbazides involved two molecules of the starting material to result in 14-membered cyclic bis-semicarbazones, 1,2,4,8,9,11-hexaazacyclotetradeca-7,14-diene-3,10-diones. The 4-(γ-oxoalkyl)semicarbazide hydrazones were prepared according to a four-step synthesis based on amidoalkylation of the sodium enolates of 1,3-diketones with ethyl N-(1-tosylalk-1-yl)carbamates followed by base-promoted retro-Claisen reaction and treatment of the obtained ethyl N-(γ-oxoalkyl)carbamates with hydrazine.
