The mesomorphic, optical, orientation, and dielectric properties of a nematic liquid crystal (LC) of 4-pentyl-cyclohexyl-4-benzonitrile (5PCH) doped with optically active (bis)camphoralidene-ethylenediamine (C2-bisCamN) have been studied. On the basis of the analysis of mesophase textures, the chiral nematic induction has been detected with the addition of dopant. The helical pith of the induced chiral nematic in mixtures has been measured by the Grandjean–Cano method and the helical twisting power has been estimated. It has been shown that the chiral induction effectiveness decreases with increasing dopant concentration because of association. The clearance temperatures of the mixtures have been measured and the degree of destabilization of the mesophase with the introduction of dopant was assessed by the method of the polarization thermomicroscopy. The effect of a chiral dopant on the mesophase anisotropic characteristics such as: dielectric permeability and birefringence, has been studied. It has been found that the introduction of C2‑bisCamN and the formation of a chiral mesophase are accompanied by a decrease in dielectric and optical anisotropy and orientational ordering. In this case, the main contribution to the change in anisotropic characteristics has been made by the helical twisting and the local orientation of the “quasi-nematic” layers. The associative state of the mesophase of the binary systems based on the strongly polar cyan derived LCs has been evaluated using the Kirkwood correlation factor. A decrease in the degree of the antiparallel dipole-dipole association of 5PCH with an increase in the concentration of the additive has been shown. The optimized structures of the monomers and dimers of 5PCH, C2-bisCamN, and solvates based on them have been obtained using quantum chemical calculations. Analysis of the geometric parameters (anisotropy of shape and molar volumes), polarity, optical activity, and the stability energies of the monomers and supermolecules has allowed us to identify camphorodiimine associates as the most likely structures responsible for the properties of the induced chiral mesophase in the 5PCH + C2-bisCamN system.

The title compound, tert-butyl (6-(3-(3-fluorophenyl)ureido)hexyl)carbamate, was synthesized and characterized by NMR, MS, elemental analysis, and single-crystal X-ray diffraction. This urea can serve as a framework for the preparation of unsymmetrical diureas or compounds containing both urea and thiourea groups.

A series of 1,3-disubstituted ureas containing a 4-(hydroxyadamantan-1-yl)-fragment were synthesized in yields of 55–87

The mini-review is devoted to the influence of the structure and properties of chiral macroheterocyclic dopants on the induction of helical liquid-crystalline phases. Using the example of solutions of synthetic porphyrins, camphor substituted hemiporphyrazines and tetrapyrazinoporphyrazines, as well as chemically modified natural macrocycles based on chlorin e6 derivatives and their metal complexes in nematic liquid crystals, the features of the mesomorphic, dielectric and rheological properties of induced spiral mesophases are discussed. The brief review is devoted to influence of the molecular structure and optical activity of chiral macroheterocycles on the efficiency of induction of helical liquid-crystalline phases. A strong effect of macrocycles acoplanarity and interactions with LC on the helical pitch and phase transitions of induced phase was established. image

A series of 1,3-disubstituted ureas and diureas was synthesized by the reaction of (3-bromoadamantan-1-yl)isocyanate with aliphatic diamines, fluorine-containing anilines, and trans-4-amino-(cyclohexyloxy)benzoic acid in 36–85% yields. Hydrolysis of (3-bromoadamantan-1-yl)isocyanate in the presence of catalytic amounts of DBU afforded symmetrical 1,3-bis-((3-bromadamantan-1-yl)urea in 60% yield. are promising inhibitors of human soluble epoxide hydrolase hsEH.

In the 1H NMR spectra (DMSO-d6) of 1,3-disubstituted ureas containing the 4,7,7-trimethyl-3-oxo-4-oxabicyclo[2.2.1]heptan-1-yl substituent, the signals for the CH2—CH2 moiety appear as an ADMP-type spin system consisting of four doublets of doublets of doublets with chemical shifts in the range from 1.54 to 2.80 ppm. The experiment in CD3OD showed the disappearance of the signal at δ 2.80 and a change in the multiplicity of the other signals, which is indicative of the selective deuterium exchange of one of the four protons of the CH2—CH2 group for a deuterium atom. This allows the selective modification of compounds containing the oxacamphanyl moiety.

An overview of the main scientific achievements of Russian universities in the field of organic chemistry over the period 2018–2023 is presented.

For the first time, a comprehensive study of the mesomorphic, physical and orientation properties of helical mesophases induced by partially acylated cyclodextrins was carried out. Using polarisation microscopy, the formation of a helical mesophase was established when a nematic mixture of polar 4-alkoxy-4'-cyanobiphenyls (CB-2) was doped with chiral 2,3-per-acetylated and 2,3-per-propionylated alpha- and beta-cyclodextrins. The clearance temperatures and helical pitch were measured. The high efficiency of helix twisting under the influence of these dopants and an increase in the orientational order parameter of the liquid crystal matrix were ascertained. Using Haller's extrapolation method for approximation the temperature dependences of birefringence a decrease in inverse helix pitch (1/p) upon heating was shown to be due to a reduction in the LC order parameter. Quantum chemical simulation of the acetylated alpha- and beta-cyclodextrins structure and their solvates with 4-pentyloxy-4'-cyanobiphenyl was performed, and their interaction energies and dipole moments were calculated. The formation of inclusion compounds of LC molecules into the internal cavity of acylated CDs was established. The higher interaction energy and helical twisting power, as well as the least destabilisation of the mesophase were shown to be observed for beta-cyclodextrin derivatives.

Methods have been developed for the synthesis of N-[2-(adamantan-2-yl)ethyl]-N′-R-ureas and -thioureas in 36–87

A series of N,N′-disubstituted ureas and bis-ureas were synthesized in 36–85

Methods for the preparation of 1-[2-(adamantan-2-yl)ethyl]-3-R-ureas and thioureas by the reaction of 2-(adamantan-2-yl)ethylamine with aromatic isocyanates and isothiocyanates with 36–87% yields were developed. It was found that the displacement of the ethylene bridge from the 1st to the 2nd position of the adamantyl radical does not significantly affect the value of log P and melting points of the corresponding compounds.

Inhibition of soluble epoxide hydrolase (sEH) is a promising therapeutic strategy for treating neuropathic pain. These inhibitors effectively reduce diabetic neuropathic pain and inflammation induced by Freund’s adjuvant which makes them a suitable alternative to traditional opioids. This study showcased the notable analgesic effects of compound AMHDU (1,1′-(hexane-1,6-diyl)bis(3-((adamantan-1-yl)methyl)urea)) in both inflammatory and diabetic neuropathy models. While lacking anti-inflammatory properties in a paw edema model, AMHDU is comparable to celecoxib as an analgesic in 30 mg/kg dose administrated by intraperitoneal injection. In a diabetic tactile allodynia model, AMHDU showed a prominent analgesic activity in 10 mg/kg intraperitoneal dose (p < 0.05). The effect is comparable to that of gabapentin, but without the risk of dependence due to a different mechanism of action. Low acute oral toxicity (>2000 mg/kg) and a high therapeutic index makes AMHDU a promising candidate for further structure optimization and preclinical evaluation.

The study is dedicated to the investigation of the catalytic activity of zinc carboxylates in the condensation reaction of camphor with aliphatic diamines. The reaction of camphor with 1,6-hexanediamine was selected as the model system. The research demonstrated that the reaction does not proceed without a catalyst, while the use of zinc carboxylates as catalysts leads to a higher conversion and selectivity compared to the classical catalyst for this reaction, Et2O center dot BF3. The best results were achieved using zinc 2-ethylhexanoate, which provided an 88.4 % conversion of camphor and a 76.9 % selectivity for the formation of diimine. It was established that the catalytic activity of zinc carboxylates in the condensation reaction of camphor with diamines is related to the structure of the acid residue of the salt. Based on the obtained data, a reaction mechanism was proposed, associated with the formation of a complex between the zinc carboxylate and the initial amine, which is confirmed by FTIR and UV-vis spectroscopic data.

A procedure has been developed for the synthesis of 3,5-difluoroadamantan-1-yl isocyanate from 3,5-difluoroadamantane-1 carboxylic acid and diphenylphosphoryl azide using a new fluorinating agent, Ishikawa reagent, in one stage of the synthesis. The reaction of 3,5-difluoroadamantan-1-yl isocyanate with aliphatic diamines and trans-4-[(4-aminocyclohexyl)oxy]benzoic acid afforded a series of N,N′-disubstituted ureas and bis-ureas in 43–96

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This research aims to explore how functionally active structures affect the physical, mechanical, thermal, and fire-resistant properties of elastomeric compositions using ethylene-propylene-diene rubber as a base. The inclusion of aluminosilicate microspheres, microfibers, and a phosphorus-boron-nitrogen-organic modifier in these structures creates a synergistic effect, enhancing the material's heat-insulating properties by strengthening coke and carbonization processes. This results in a 12-19% increase in heating time for unheated sample surfaces and a 6-17% increase in residual coke compared to existing analogs. Microspheres help counteract the negative impact of microfibers on composition density and thermal conductivity, while the phosphorus-boron-containing modifier allows for controlling the formation of the coke layer.

The mesomorphic, optical, and dielectric properties of a nematic mixture of 4-pentyloxy- and 4-heptyloxy-4′-cyanobiphenyls doped with optically active (bis)camphoralidene-hexamethylenediamine were studied. The clearance temperatures of the mixtures were measured using polarization microscopy to assess the degree of destabilization of the mesophase upon dopant introduction. Additionally, the helical pitch of the induced chiral nematic phase in the mixtures was measured, and the influence of the chiral dopant on the mesophase’s anisotropic characteristics was investigated.

The compound 1-(3-chlorophenyl)-3-(6-((1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene)amino)hexyl)thiourea was synthesized for the first time from 6-((1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene)amino)hexan-1-amine and 3-chlorophenylisothiocyanate in DMF with a 60% yield. It was characterized by 1H, 13C{1H} NMR, FT-IR, MS, and elemental analysis.

An experimental and theoretical study of structure and properties of chiral amphiphilic chlorin e6 13(N)-methylamide-15-methyl,17-alkyl esters (17-pentadecyl 1 and 17-phytyl 2) and their Ni complexes (Ni-1 and Ni-2) and their helical twisting efficiency in liquid crystal were carried out. Quantum chemical simulation of their structure was performed, the adequacy of which was established by comparing the calculated and experimental UV/Vis, CD, H-1 and C-13 NMR spectra as well as optical rotation angles. Low values of g-factors of dissymmetry for macroheterocycle (MHC) with the phytol substituent were experimentally revealed. The reason for this effect, associated with the transfer of the chirality from the stereogenic centers of the substituent to macrocyclic chromophore in the associate, was established by quantum-chemical calculation. Using polarization microscopy, the formation of chiral nematic phases was detected by doping a mixture of cyanobiphenyls with macroheterocycles 1, 2, Ni-1 and Ni-2. The values of the clearance temperature and helical pitch were measured, the slopes of phase diagrams beta and helical twisting power (HTP) were calculated. The orientation order parameters of dopants in liquid crystal (LC) were determined by polarization spectroscopy. The dielectric properties of LC-MHC systems were studied within the chiral nematics and isotropic phases, and the values of the Kirkwood's correlation factors were calculated. Using quantum chemical simulation of MHC solvates, the features of the influence of aliphatic chains structure and complex formation on the physical properties of induced mesophases were established.