High catalytic activity of the PdCl2(PPh3)2–PPh3–AlCl3 system containing AlCl3 as promotor has been demonstrated in the reaction of hydroethoxycarbonylation of hexene-1 and octene-1 at low pressure of carbon(II) oxide (≤25 atm). The reaction yields linear and branched products. The optimal conditions of the process have been elaborated. The target products yield is 84.6–93.8%.

The possibility for the synthesis of 5-chloro-2-hydroxybenzoic, 4-chloro-2-hydroxybenzoic, and 3-chloro-2-hydroxybenzoic acids via regioselective carboxylation of p-, m-, and o-chlorophenols, respectively, with sodium ethyl carbonate has been demonstrated. Simple and convenient procedures developed in this study for the synthesis of chlorohydroxybenzoic acids can be used for their preparative and industrial synthesis.

Carboxylation of o-cresol, m-cresol, and p-cresol with sodium ethyl carbonate (SEC) proceeds regioselectively with the formation of cresotic acids: 2-hydroxy-3-methylbenzoic acid, 2-hydroxy-4-methylbenzoic acid, and 2-hydroxy-5-methylbenzoic acid, respectively. Optimal conditions for conducting the process have been found to be as follows: the reactants ratio of [cresol]: [sodium ethyl carbonate] = (1.5–2): 1, T = 180–185°C, \({P_{C{O_2}}}\) = 10 atm, and t = 6–7 h. Simple and convenient methods for the synthesis of cresotic acids, which can be used for their industrial manufacturing, have been developed.

The use of carbon dioxide as a carbon source for organic synthesis is an important problem of modern organic chemistry and petroleum chemistry. The utilization of carbon dioxide in chemical synthesis is also of great environmental importance, because it is one of the ways to reduce atmospheric emission of CO2, the main component of greenhouse gases. So far, only two processes based on CO2 have been implemented on the industrial scale, the synthesis of urea (carbamide) and that of salicylic acid. The carbon dioxide molecule has a low reactivity; so, the overwhelming majority of its reactions proceed only under special conditions: upon the activation with metal complexes, with the use of catalysts, under severe conditions of the process, etc. At the same time, some simplest derivatives of carbon dioxide are quite active. The analysis of the literary dates on one of the most perspective directions in using carbon dioxide in organic synthesis - synthesis of carboxylic acids by carboxylation of organic compounds with carbon dioxide and its derivatives - is carried out. Contrary to the widespread representations carbon dioxide is capable to enter various reactions with other molecules. Carbon dioxide much more concedes to carbon monoxide on volume of use in industrial organic synthesis. In the future in the process of development of carbon dioxide chemistry, the volume of using of the carbon dioxide in organic synthesis, undoubtedly, will grow in the accelerated rate.

Hydroalkoxycarbonylation of olefins with carbon monoxide and alcohols under condition of homogeneous –catalysis with transition metal complexes allows facile one-step synthesis of practically useful carbon acid esters. Many of them have biological activity and are constituents of drugs or valuable intermediate products in drug synthesis. Hydroalkoxycarbonylation of isobutylene with carbon monoxide and alcohols in the presence of catalytic system Pd(PPh3)4-PPh3-TsOH was applied for preparing of biological active isovaleric acid esters: 1-menthylisovalerate (main active component of the spasmolytic medicine “Validolum”), ethylisovalerate (intermediate product for obtaining sedative and spasmolytic medicines “Ethyl ester of α-bromisovaleric acid” and “Corvalolum”), cyclohexylisovalerate (bactericide activity) and benzylisovalerate (bactericide and antifungus activity). Hydroalkoxycarbonylation reaction of isobutylene with carbon monoxide and alcohols (ethanol, cyclohexanol, l-menthol, benzyl alcohol) in the presence Pd(PPh3)4-PPh3-TsOH system carried out at conditions: temperature 100 °C; CO pressure 2.0 MPa; reaction time 4 h; reactants and catalyst components ratio [alcohol]:[isobutylene]:[Pd(PPh3)4]:[PPh3]:[TsOH] = 435:550:1:3:12. The yields of the products were 71-95% (on converted alcohols). The selectivity in linear reaction products was 100%. Such a high regioselectivity is apparently provided both by the structure of the starting alkene (isobutylene) and by the reaction mechanism. The most probable is a hydride mechanism. Due to the more advanced technology of production the Medicines will have better qualitative characteristics. The cost of production of the Medicines with the use of new technologies is 2-3 times lower as compared to the medicines produced by existing at the present traditional technologies.

The reaction of isobutylene hydroalkoxycarbonylation at low carbon monoxide pressures (≤2.0 MPa) with ethylene glycol and glycerol in the presence of catalytic systems based on Pd and mono- and bidentate organic phosphines has been studied. The effect of different conditions of the reaction in the presence of the Pd(Acac)2-PPh3-TsOH catalyst system on the ratio of the products, mono- and diglycolides (mono-, di-and triglycerides) of isovaleric acid has been investigated. The relative catalytic activity of a number of binary and ternary systems based on synthesized Pd(Acac)2, Pd(PPh3)4, and PdCl2(PPH3)2 complexes has been determined.

The catalytic activity of the Pd(PPh3)4-TsOH and Pd(PPh3)4-PPh3-TsOH systems in the reaction of isobutylene hydromenthoxycarbonylation with carbon monoxide and l-menthol has been examined. It has been found that the reaction proceeds regioselectively yielding the linear product l-menthyl isovalerate. Optimal conditions have been found for running the process. The spatial structure of l-menthyl isovalerate synthesized via the isobutylene hydromenthoxycarbonylation reaction has been established by 1H and 13C NMR techniques.

High catalytic activity of the Pd(PPh3)-PPh3-TsOH system in the reaction of the isobutylene hydromethoxycarbonylation and hydroethoxycarbonylation of the hexene-1 was estimated. The reactions are running with high selectivity related to liner products.The optimal conditions of the process were determined.

Modern achievements in the chemistry of carbon dioxide have been considered. When utilizing carbon dioxide in chemical synthesis, two groups of reactions: reactions of carboxylation (carboxyamidation) of organic compounds with carbon dioxide and reactions of carbon dioxide reduction – are supposed to be the most prospective.

The advanced method for the synthesis of hydroxyaromatic acid via carboxylation of hydroxyarenes by alkaline salts of carbonic acids is shown.

Published data on the carboxylation of organic compounds with salts of alkyl carbonic acids (metal alkyl carbonates) are surveyed.

Проведен анализ литературных данных по карбоксилированию органических соединений солями алкилугольных кислот (металлалкилкарбонатами).

The reaction of isobutylene hydroxycarbonylation with carbon monoxide and an alcohol (ethanol, 1-menthol) in the presence of the palladium acetylacetonate-triphenylphosphine-p-toluenesulfonic acid catalytic system was investigated. It was shown that the reaction proceeds regioselectively with the formation of linear products (ethyl isovalerate, 1-menthyl isovalerate). The optimum conditions for running the process were found, at which the yield of the main products is 67–79%.

Several types of catalyst systems were examined in the olefin hydroalkoxycarbonylation reaction. The systems contained Pd(PPh3)4, PdCl2(PPh3)2, or some other palladium compounds as a principal component. The second component (promoter) was p-toluenesulfonic acid or diphenyl(m-sulfophenyl)phosphine, which combines both the ligand and promoter functions. An important feature of these systems is their high activity in the hydroalkoxycarbonylation of ethylene and a high regioselectivity (83–100%) in the hydroalkoxycarbonylation of α-olefins with respect to linear products. Thus, it was unnecessary to introduce additional stabilizing ligands to augment the catalyst and promoter. The esters obtained can find application in the pharmaceutical industry and perfumery, as well as in other industries.