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

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.

The Chan–Lam reaction conditions were optimized for the synthesis of N -aryl derivatives of adamantane-containing amines. A number of adamantane-containing amines and diamines with different steric hindrances at the primary amino groups were reacted with p -tolylboronic acid under the optimized conditions [0.1 M solution of amine in MeCN, p -tolylboronic acid (2 equiv), DBU (2 equiv), copper(II) acetate (20 mol %), 25°C, 24 h]. The reactivity of the amines was found to strongly depend on their structure, and the maximum yield of the target products reached 74% from the monoamines and 66% from the diamines.

It was shown that the optical and dielectric properties of polyimides (PIs) are affected by both the presence of an alicyclic fragment and the non-coplanarity of the structural elements of the polymer chain. The combination of these factors contributed to an increase of the transparency of the PIs in the optical range and a decrease of the dielectric constant. It was determined that the introduction of 20 mol.% adamantane-containing diamine into the PI structure contributed to its more complete amorphization and increased its transparency.

The hydrolytic stability of polyimide films (PI) in a 0.9% sodium chloride solution in the temperature range of existing biological objects was studied. The kinetic parameters of hydrolysis of PI films were calculated. It was established that the hydrolysis rate constant of an adamantane-containing film was significantly lower than that of an industrial Kapton film. The dielectric constant after hydrolysis was determined. It was shown that the dielectric properties of the adamantane-containing polymer remained unchanged under the hydrolysis conditions.

N -(Het)arylation of adamantane-containing amines with halonaphthalenes and haloquinolines catalyzed by either CuI or copper nanoparticles with an average size of 25 nm in the presence of 2-isobutyrylcyclohexanone, rac -BINOL, and l -proline as a ligand and Cs 2 CO 3 as a base in DMSO at 110 °C was studied. The reactions proceed smoothly with 2-iodonaphthalene and 6-iodoquinoline, the possibility of successful reactions with 6- and 3-bromoquinolines was also shown. In the case of 1-bromonaphthalene, 5- and 8-bromoquinolines, only Pd-catalyzed amination can provide the high yields of the products. An alternative possibility of C(sp 2 )—N bond formation was studied employing the Chan—Lam reaction with of 2-naphthaleneboronic acid and pinacolates of 6- and 3-quinolineboronic acids.

The regularities of the reduction of unsaturated nitriles containing the 2-adamantyl fragment with lithium aluminum hydride and nickel—aluminum alloy were studied. In both cases, the double bond and nitrile group were simultaneously reduced. The presence of bulky substituents in the substrate in the α-position to the adamantyl fragment and hydroxy groups significantly retards the process, and the 80–90

The regularities of obtaining polyimides by high-temperature polycyclization in various solvents have been studied. It is shown that the use of sulfolane as a solvent makes it possible to obtain polymers with a higher reduced viscosity and, accordingly, a better potential set of characteristics. Polyimides based on vicinally substituted bicyclic diamines have a higher molecular weight compared to polyimides based on 9.9-bis-(4-aminophenyl) fluorene.

The N-heteroarylation of n-octylamine and adamantane-containing amines with 2-iodopyridine and 2-bromopyridine and its fluorinated derivatives under the catalysis of CuI and copper nanoparticles in DMSO in the presence of various ligands was studied. 2-Isobutyrylcyclohexanone was found to be the most efficient ligand in the reactions catalyzed by CuI. In the reactions catalyzed by copper nanoparticles, 2-isobutyrylcyclohexanone or l-proline turned to be most active. The yields of the reactions catalyzed by copper nanoparticles were better than or equal to those in the CuI-catalyzed processes. The possibility of nanocatalyst recycling was studied, and its reuse in 6 cycles without loss of activity was demonstrated.

Optically transparent polyimides (PIs) containing adamantane moieties in the structure of diamine unit were synthesized, and their properties were evaluated. The quantum-chemical calculations were also performed and revealed the energy difference (As) between the HOMO of the diamine and LUMO of the anhydride moieties for a large range of adamantane-containing PIs, which is usually associated with the optical absorption of organic compounds. It was found that the value of As does not always determine the optical properties of PI, especially in the case of PI with dianhydride moieties capable of strong intermolecular interactions. The presence of methyl groups at the core of adamantane-containing diamine leads to amorphization of the polymer, causing a positive effect on the optical properties of PI.

N-Arylation of n -octylamine and adamantane-containing amines with iodobenzene and its deriva­tives has been performed in DMSO using copper(I) iodide and copper nanoparticles in the presence of various ligands as catalysts. In all cases, 2-isobutyrylcyclohexanone turned out to be the most efficient ligand, and higher yields of the arylation products were obtained in the presence of copper nanoparticles. The nanocatalyst can be recycled 9 times without significant loss of yield.

Comparison of the homogeneous and heterogeneous copper-catalyzed arylation of model primary amines with (hetero)-aryl iodides in DMSO revealed a comparable efficiency of CuI and commercially available unsupported copper nanoparticles (25 nm size) in the presence of 2-isobutyryl-cyclohexanone or L-proline.

For the first time, a study of the reaction of pyromellitic dianhydride with [3-(aminomethyl)bicyclo[2.2.1]hept-2-yl]anilines by the calorimetric method was carried out. The enthalpies, rate constants and activation energies of the reaction were determined. It was found that the reactivity in the reactions of the formation of polyamide acids, [3-(aminomethyl)bicyclo[2.2.1]hept-2-yl]anilines are significantly superior to aromatic diamines. It was shown that in the case of 3-[3-(aminomethyl)bicyclo[2.2.1]hept-2-yl]aniline pK(a) values do not fully take into account steric factors and, therefore, are not a sufficiently sensitive measure of the reactivity of [3-(aminomethyl)bicyclo[2.2.1]hept-2-yl]anilines in the reactions of polyamide acids formation.

N-heteroaryl substituted adamantane-containing amines are of substantial interest for their perspective antiviral and psychotherapeutic activities. Chlorine atom at alpha-position of N-heterocycles has been substituted by the amino group using convenient nucleophilic substitution reactions with a series of adamantylalkylamines. The prototropic equilibrium in these compounds was studied using NMR spectroscopy. The introduction of the second amino substituent in 4-amino-6-chloropyrimidine, 2-amino-chloropyrazine, and 1-amino-3-chloroisoquinoline was achieved using Pd(0) catalysis.

New (co)polyimides possessing good thermal and physicomechanical characteristics, high hydrolytic stability, and transparency at the best world level were synthesized. It was shown that, depending on the natures of diamine and dianhydride used in the synthesis, the optical properties of polymers also change. These properties of (co)polyimide films correlate with the ΔE value, which is defined as the difference between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies of the polyimide repeating unit. It was shown that the use of 1,2-dichlorobenzene makes it possible to obtain high-molecular-weight (co)polyimides with a set of enhanced performance characteristics.