Julia K. Voronina

Acid-Catalyzed Reaction of (4,4-Diethoxybutyl)ureas with Phenols as a Novel Approach to the Synthesis of α-Arylpyrrolidines

Abstract 1-(4,4-Diethoxybutyl)-3-alkylureas undergo intramolecular cyclization in the presence of trifluoroacetic acid and various phenols, leading to the new N-alkyl-2-arylpyrrolidine-1-carboxamides with moderate to excellent yields. It was found that these compounds undergo spontaneous solid-phase epimerization at room temperature. Advantages of the proposed approach are mild reaction conditions and no need for expensive reagents or catalysts. GRAPHICAL ABSTRACT

Single step preparation and conformational analysis of novel thiophosphorylated ligands based on calix[4]resorcinol matrix

We have synthesized novel calix[4]resorcinols with four 2-thioxo-1,3,2-dioxaphospholane groups introduced in aromatic substituents in the methylidene bridges of macromolecules by the condensation of new thiophosphorylated benzaldehyde with resorcinol and its derivatives in acidic media with high yields. The formation of only one rctt isomer with corresponding chair conformation is observed, which was determined by 2D NMR-experiments.

Synthesis and antimicrobial activity evaluation of some novel water-soluble isatin-3-acylhydrazones

By acid-catalyzed reaction of substituted isatins with Girard’s reagent T, new water-soluble isatin-3-acylhydrazones were obtained with high yields. Their antimicrobial activity was evaluated. Selective activity against Gram-positive bacteria (S. aureus 209p and B. cereus 8035) and yeast-like fungus Candida albicans 855–653 along with low hematoxicity was established.Graphical abstract

Acid-catalyzed intramolecular cyclization of N-(4,4-diethoxybutyl)sulfonamides as a novel approach to the 1-sulfonyl-2-arylpyrrolidines

ABSTRACT Herein we report our studies on the acid-catalyzed cyclisation of N-(4,4-diethoxybutyl)sulfonamides at the presence of polyatomic phenols as an efficient one-pot approach to the synthesis of 1-sulfonyl-2-arylpyrrolidines from the acyclic precursors. GRAPHICAL ABSTRACT

Synthesis and Structure of Aminophosphonates Containing 3,5-Di-Tert-Butyl-4-Hydroxyphenyl and Acetal Groups

GRAPHICAL ABSTRACT Abstract The reactions of dialkyl [(3,5-di-tert-butyl-4-oxo-2,5-cyclohexadienyl)methyl]phosphonates with N-nucleophiles (aminoacetaldehyde dimethyl acetal and diethyl [(2,2-dimethoxyethyl)aminomethyl]phosphonate give new aminophosphonates containing the 3,5-di-tert-butyl-4-hydroxyphenyl substituent, in addition to the acetal group. The crystal structure of diethyl {(3,5-di-tert-butyl-4-hydroxyphenyl)[(2,2-dimethoxyethyl)amino]methyl}phosphonate is elucidated. The presence of a chiral carbon atom and prochiral phosphorus atom in the aminophosphonate products is responsible for the complicated pattern in the 1H NMR spectra, the features of which are discussed.

Synthesis and binding ability of mono- and tetrasubstituted aminophosphonate Zn-tetraarylporphyrins towards N- and O-containing organic substrates

The 1,6-addition of mono- and tetra-amino 5,10,15,20-tetraphenylporphyrins with dimethyl-(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidenemethyl)phosphonate leads to the corresponding mono- and tetrasubstituted aminophosphonate porphyrin derivatives. The binding ability of their Zn(II)-complexes towards 1,4-diazabicyclo[2,2,2]octane, imidazole, 4-(1H-imidazole-1-yl)benzyl alcohol and 4-(1H-imidazole-1-ylmethyl)benzyl alcohol in toluene was investigated by spectrophotometric and 1H NMR titration. It has been determined that the monosubstituted Zn-tetraarylporphyrin is involved in a two-point selective binding of 4-(1H-imidazole-1-ylmethyl)benzyl alcohol. Taking into account the fact that this binding is accompanied by a clear and easily identifiable response in the UV–vis spectra of the reaction mixture, this metalloporphyrin could be considered as a molecular optical sensing device for selected bidentate N- and O-containing substrates.

A New Method for the Synthesis of Substituted 8,9,10,11-Tetrahydroindolo[1,2-a]Quinoxalin-6(5H)-Ones

The reaction of 1-(cyclohexen-1-yl)pyrrolidines with 3-(α-chlorobenzyl)quinoxalin-2(1H)-ones resulted in the formation of 8,9,10,11-tetrahydroindolo[1,2-a]quinoxalin-6(5H)-ones via a tandem sequence of Stork enamine alkylation and intramolecular annulation. Oxidative dehydrogenation gave indolo[1,2-a]quinoxalin-6(5H)-one.

Nanoscale isoindigo-carriers: self-assembly and tunable properties

Over the last decade isoindigo derivatives have attracted much attention due to their high potential in pharmacy and in the chemistry of materials. In addition, isoindigo derivatives can be modified to form supramolecular structures with tunable morphologies for the use in drug delivery. Amphiphilic long-chain dialkylated isoindigos have the ability to form stable solid nanoparticles via a simple nanoprecipitation technique. Their self-assembly was investigated using tensiometry, dynamic light scattering, spectrophotometry, and fluorometry. The critical association concentrations and aggregate sizes were measured. The hydrophilic–lipophilic balance of alkylated isoindigo derivatives strongly influences aggregate morphology. In the case of short-chain dialkylated isoindigo derivatives, supramolecular polymers of 200 to 700 nm were formed. For long-chain dialkylated isoindigo derivatives, micellar aggregates of 100 to 200 nm were observed. Using micellar surfactant water-soluble forms of monosubstituted 1-hexadecylisoindigo as well as 1,1′-dimethylisoindigo were prepared for the first time. The formation of mixed micellar structures of different types in micellar anionic surfactant solutions (sodium dodecyl sulfate) was determined. These findings are of practical importance and are of potential interest for the design of drug delivery systems and new nanomaterials.

New aminophosphonates (aminophosphine oxides) containing acetal groups in reactions with polyatomic phenols

GRAPHICAL ABSTRACT ABSTRACT A wide range of phosphorylated α-,β-,γ-aminoacetals of various structure were obtained by Kabachnik-Fields reaction. Acid-catalyzed reactions of phenols with α-,β-,γ-aminoacetals provide a new approach to the synthesis of different polyphenols, containing aminophosphonate and aminophosphine oxide moieties, arylsubstituted heterocycles containing phosphonate and phosphinoxide groups. Herein we present a short overview of these reactions.

Metal binding properties of pyrimidinophanes and their acyclic counterparts

A series of acyclic and macrocyclic nucleobase derivatives that contain uracil and 2-thiocytosine units linked by polymethylene spacers was prepared. The length of spacers as well as the oxidation number of sulfur atoms entering into the structure of the compounds was varied. The crystal structure of pyrimidinophane with hexa- and heptamethylene linkers was established by X-ray analysis. The metal ion-binding properties of pyrimidinophanes and their acyclic counterparts were investigated by liquid extraction and 1H NMR titration experiments. The compounds with 2-thiocytosine fragments revealed a high selectivity of extraction towards Ag+ ions. The stoichiometry of silver complexes and the binding constants have been determined. The antibacterial activity of these complexes was also discussed.