Copper-based metal-organic frameworks (Cu-MOFs) were successfully used for the amination of aryl iodides for the first time. The conditions were selected using four different Cu-MOFs in a model reaction of n-octylamine with iodobenzene. Efficient reaction requires the use of O,O′-bidentate ligands (2-acetylcyclohexanone, 2-isobutyrylcyclo-hexanone, rac-1,1′-bi(2-naphthol), or rac-BINOL), and, in the best cases, the yields of N-octylaniline can exceed 80

The efficiencies of copper-containing metal–organic coordination polymers (Cu-MOFs) and com­mercially available unsupported copper nanoparticles (CuNPs) in the amination of 2-iodopyridine, 2-bromo­pyridine, 2-bromo-5-(trifluoromethyl)pyridine, and 2-bromo-6-(trifluoromethyl)pyridine with n-octylamine and adamantane-containing amines with different steric environments of the amino group have been compared. Under the optimized conditions, the yields of the amination products in the presence of both catalytic systems were generally similar. In the reactions with 2-bromopyridine, increased reactant concentration and the use of 2 equiv of the substrate were necessary to achieve good yields. The presence of a trifluoromethyl group at the 6-position of the pyridine ring improved the yield of the amination products. An increase in steric hindrances at the amino group resulted in an appreciable decrease in the yield under catalysis by Cu-MOFs; however, reactions with such amines were successfully performed in the presence of CuNPs, and CuNPs of the average size 25 nm proved to be superior to bifractional nanoparticles with average sizes of 10 and 80 nm. On the other hand, increased concentration of the reactants in the Cu-MOF-catalyzed amination provided good yields of the target compounds in the absence of a ligand.

A number of alicyclic (co)polyimides were synthesized and the effect of charge transfer complexes (CTCs) formed between the polymer fragments and solvent molecules on the properties of the (co)polymers was studied. It was shown that the presence of an adamantane-containing comonomer significantly reduces intermolecular interactions, which has a positive effect on the optical properties of the polyimides including light transmittance, chromaticity, etc. The use of 1,2-dichlorobenzene as solvent instead of sulfolane leads to more transparent polyimides. According to quantum chemical calculations, this is due to a decrease in the effect of CTCs.

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.

It was shown that copolyimides based on adamantane-containing diamine and dianhydrides of 2,3,3′,4′-biphenyltetracarboxylic acid (a-BPDA) and 5,5′-(1,1,1,3,3,3-hexafluoropropane-2,2-diyl)bis(2-benzofuran-1,3-dione) (6FDA) are characterized by good thermal-oxidative properties (T5

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.

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 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.

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.

A comparative study of the catalytic efficiency of Pd(0) and Cu(I) complexes in the reactions of adamantanamines with fluoro- and trifluoromethyl-substituted 2-bromopyridines was carried out using previously optimized catalytic systems. It was shown that in the absence of steric hindrances in the starting compounds, the copper and palladium catalysts were comparable in efficiency. In some cases, the yields of the target N-heteroarylated compounds in the copper-catalyzed reactions were even higher, which can be explained by the formation of N,N-diheteroarylated by-products under palladium-catalyzed conditions. At the same time, ortho-fluorine- and ortho-trifluoromethyl-substituted 2-bromopyridines successfully react exclusively under palladium catalysis.

Alkylation of N -aryl and N -arylalkyl acetamides with hydroxy adamantane derivatives in trifluoroacetic acid was studied. The differentiating effect of trifluoroacetic acid on the regio-selectivity of adamantylation of o -alkyl-substituted acetanilides was established, leading to energetically more stable products of para -substitution with respect to the alkyl group (the content of para-alkyl isomers is 93–94%). This enabled the synthesis of adamantylaminoarenes in 83–99% yields and with 95–99% purity.

Cu(I)-Catalyzed and catalyst-free amination of 2-fluoro-5-iodopyridine with adamantylalkyl amines possessing different steric hindrances at amino group was investigated to obtain corresponding 5-amino-2-fluoro- and 2-amino-5-iodopyridines. The competition between catalytic substitution of iodine and non-catalytic substitution of fluorine was shown to take place. The catalytic system CuI/2-(isobutyryl)cyclohexanone in DMF provided yields of 5-amino-2-fluoropyridines up to 58% with stoichiometric ratio of the reagents and up to 98% with two equiv. of amines. The non-catalytic amination of 2-fluoro-5-iodopyridine provided the yields of 2-amino-5-iodopyridines up to 97%.

The catalytic efficiencies of palladium(0) and copper(I) complexes in the amination of 2-bromopyridine and its fluorine-containing derivatives with (1-adamantyl)methanamine and 2-(1-adamantyloxy)ethanamine were compared. Both types of catalytic systems were shown to be applicable for the preparation of the corresponding N-pyridyl derivatives from 3- and 5-fluoro- and 4-, 5-, and 6-trifluoromethyl-2-bromopyridines. DavePhos was found to be the most efficient ligand in the Pd(0)-catalyzed reactions; however, the reactions with 2-bromo-4-(trifluoromethyl)pyridine and 2-bromo-5-(trifluoromethyl)pyridine were accompanied by formation of a considerable amount of the diarylation product. The diarylation process was significantly suppressed in the presence of copper(I) complexes.

Palladium-catalyzed heteroarylation of adamantylalkyl amines characterized by different steric hindrances at the amino group was carried out using 2,3-, 2,5-, 2,6-, and 3,5-dihalogenopyridines. The dependence of the results of the coupling on the nature of the halogen atoms (bromine, chlorine), their position in the pyridine ring, and on the structure of adamantylalkyl amines was investigated. The application of dichloropyridines or bromochloropyridines was shown to be advantageous over the use dibromopyridines in many cases. Selective substitution of bromine atom in positions 3 and 5 in the presence of chlorine atom in position 2 of the pyridine ring was observed. The possibility of N, N-diheteroarylation of adamantane-containing amines with 2,5-dihalogenopyridines was shown, and diamination of 2,6-and 3,5-dihalogenopyridines was demonstrated.

Triphenylphosphine-catalyzed [3 + 2] cycloaddition between ethyl buta-2,3-dienoate and adamantane-containing N-substituted maleimides affords substituted bicyclic succinimides in excellent yields.