Nucleophilic Substitution at Tetracoordinate Phosphorus.Stereochemical Course and Mechanisms of Nucleophilic Displacement Reactions at Phosphorus in Diastereomeric cis- and trans-2-Halogeno-4-methyl-1,3,2-dioxaphosphorinan-2-thiones: Experimental and DFT Studies

Geometrical cis- and trans- isomers of 2-chloro-, 2-bromo- and 2-fluoro-4-methyl-1,3,2-dioxaphosphorinan-2-thiones were obtained in a diastereoselective way by (a) sulfurization of corresponding cyclic PIII-halogenides, (b) reaction of cyclic phosphorothioic acids with phosphorus pentachloride and (c) halogen–halogen exchange at PIV-halogenide. Their conformation and configuration at the C4-ring carbon and phosphorus stereocentres were studied by NMR (1H, 31P) methods, X-ray analysis and density functional (DFT) calculations. The stereochemistry of displacement reactions (alkaline hydrolysis, methanolysis, aminolysis) at phosphorus and its mechanism were shown to depend on the nature of halogen. Cyclic cis- and trans-isomers of chlorides and bromides react with nucleophiles (HO−, CH3O−, Me2NH) with inversion of configuration at phosphorus. DFT calculations provided evidence that alkaline hydrolysis of cyclic thiophosphoryl chlorides proceeds according to the SN2-P mechanism with a single transition state according to the potential energy surface (PES) observed. The alkaline hydrolysis reaction of cis- and trans-fluorides afforded the same mixture of the corresponding cyclic thiophosphoric acids with the thermodynamically more stable major product. Similar DFT calculations revealed that substitution at phosphorus in fluorides proceeds stepwise according to the A–E mechanism with formation of a pentacoordinate intermediate since a PES with two transition states was observed.

Phosphorylation of glycoluryl derivatives with phosphorus pentachloride

The paperpresents the research results on the synthesis and study of new organophosphorus derivatives of glycoluril, obtained on the basis of pentavalent phosphorus. New organoelement phosphorus derivatives synthesized on the basis of N-acyl-substituted glycolurilhave been obtained.They are of considerable interest due to the presence of effective reaction centers. Tetraacetyl-substituted glycoluril —2,4,6,8-tetraacetyl-2,4,6,8-tetraazabicyclo[3,3,0]octane-3,7-dione was chosen as theinitial synthon. Theuse of unsubstituted glycoluril in the reaction of direct phosphorylation by the action of phosphorus trichloride or pentachloride is not possible due to the absence of active phosphorylation centers. It was experimentally shown that the reaction proceeds with prolonged heating for at least 48 hours in an argon. Theinitial acyl derivative of glycoluril and phosphorus pentachloride in theratio of 1:6 and leads to the formation of diphosphonic complex of tetraacetylglycoluril —dihexachlorophosphorate 2,6-diacetyl-(4,8-diacetyl-2,4,6,8-tetraaza-bicyclo[3.3.0]octane-3,7-dione)-2,6-di(chloroethenyltrichlorophosphonium). The obtained compoundis a white crystalline substance unstable in air. Decomposition of the diphosphonic complex was carried out using benzaldehyde and proceeds with the formation of the corresponding dichlorophosphate derivative, also unstable in air and rapidly decomposing at room temperature.

Fluorescent and growth-regulating activity 2-phenylethenylphosphonic acid derivatives

The paper provides data on an improved method for the synthesis of 2-phenylethenylphosphonic acid dichloride by interacting of carbamide derivatives with 2-phenylethenyltrichlorophosphonium hexachloro-phosphate, which is an intermediate adduct of the reaction of styrene and phosphorus pentachloride. Readily available urea, biuret, and acetylurea have been used as transformers of the adduct. It has been shown that carbamide derivatives are not only donors of the oxygen atom, but they also bind hydrogen chloride released at the stage of complexation into the corresponding hydrochlorides. This allows obtaining the target 2-phenyl-ethenyldichlorophosphonate without admixture of the hydrochlorination by-product. The phenomenon of induced fluorescence of 2-phenylethenylphosphonic acid and its esters in the solid phase and in solution was revealed. The growth-regulating activity of 2-phenylethenylphosphonic acid and O,O-di(p-nitrophenyl)-2-phenylethenyl-phosphonate on the seed germination energy, laboratory and field germinations of grain and vegetable crops was established. It is shown that pre-sowing treatment of the Prokhorovka spring wheat seeds with a 0.0005% aqueous solution of O,O-di(p-nitrophenyl)-2-phenylethenylphosphonate leads to an increase in wheat yield by 21%, which expands the range of products for this purpose. A study of the acute toxicity of 2-phenylethenylphosphonic acid according to LeBlanc on male rats kept on a standard vivarium diet showed that it has a two-phase effect. In the first phase, there are symptoms of damage to the motor part of the peripheral nervous system in the form of local seizures and the central nervous system in the form of the general suppression of motor activity and moderate relaxation of skeletal muscles, and in the second phase, the acid manifests itself in a general toxic effect. Determination of the LD50 of 2-phenylethenylphosphonic acid showed that it belongs to the third class of toxicity – low-hazard substances.

INSTITUTE OF ORGANIC CHEMISTRY OF NAS OF UKRAINE - 80 YEARS

The article is devoted to the history and present of the Institute of Organic Chemistry of NAS of Ukraine. By Boris Paton's definition, the Institute of Organic Chemistry belongs to the memorial institutions of the National Academy of Sciences of Ukraine. On May 23, 1939, the Presidium of the USSR Academy of Sciences, according to resolution of the Council of People's Commissars of the USSR (May 8, 1939) decided to set up the Institute of Organic Chemistry and Technology of the USSR Academy of Sciences and the Institute of Organic Chemistry of the Ukrainian Academy of Sciences. There were four scientific departments in the Institute, headed by academicians of the Academy of Sciences of the Ukrainian SSR: General Organic Synthesis - V.P. Jaworski, fuel - M.I. Kuznetsov, macromolecular compounds - I.K. Matsurevich, fibrous substances and dyes - V.G. Shaposhnikov at the time of its foundation. V. P. Jaworski, the academician of the Academy of Sciences of the Ukrainian SSR, was the first Director of the Institute. Since the institute's existence, such outstanding scientists have worked in the institution as: Andrei Kiprianov (founder of the color theory of organic dyes, phenomenon of interaction of chromophores "Phenomenon AI Kiprianov", VM Zubarovsky, OI Tolmachov, Yu.L. Slominsky, OO Ishchenko, KD Sych, IK Ushenko, FA (development of preparative chemistry of thiazole, benzothiazole, benzimidazole and a number of heterocycles), E.O. Shilov (formation of p-complexes of molecules of unsaturated compounds with electrophilic reagents, substantiation of mechanisms of biochemical processes), OA Yasnikov (theory of radical transformations in reactions modeling nicotinamide coenzymes, open catalytic properties of cytochrome production technology for phospho-rylated starch), OV Kirsanov (reaction of amino compounds with phosphorus pentachloride and reaction of oxidative imination of compounds of trivalent phosphorus with dichloramines), A.F. Plate, IL Knunanciec, M.I. Kabachnik, L.M. Markovsky (Chemistry of Sulfur Organic Com-pounds) and VP Kuchar (Works on Chemistry of Phosphorus Organic Compounds), Yu. Gololobov (Chemistry of Organo-Organic Compounds), A.D. Sinitsa (Methods of Synthesis and Investigation of the Properties of Imino-Phosphonates), OI Kolodyazhny (Chemistry of Phosphorus Illides), L.M. Yagupolsky (Yagupolsky principle, Buchwald – Hartwig – Yagupolsky reaction), M.O. Lozynsky, S.V. Komisarenko (chemistry of physiologically active heterocyclic compounds), V.I. Kalchenko (molecular design, synthesis and study of supramolecular interactions of macrocyclic compounds - crowneters, calixarenes, thiacalixarenes and calixresorbins). The Institute's developments have great innovation potential today. The Institute's staff published 8,000 scientific articles, 90 monographs and obtained 1550 copyright certificates and patents. The Institute has trained 350 candidates and 65 doctors of science during its work.

Use of Triphenylphosphine-Bromotrichloromethane (PPh3-BrCCl3) in the Preparation of Acylhydrazines, N-Methylamides, Anilides and N-Arylmaleimides From Carboxylic Acids

In certain countries, many of the reagents used to transform carboxylic acids to acyl halides such as phosphorus trichloride, phosphorus tribromide, phosphorus pentachloride, phosphoryl chloride, thionyl chloride and sulfuryl chloride are difficult to come by. Against this background, the authors developed the reaction system triphenylphosphine (PPh3)–bromotrichloromethane (BrCCl3) to prepare acyl halides in situ. In the following, the use of this reagent combination is joined with the reaction of the in situ prepared acyl halides with nitrogen nucleophiles, specifically with hydrazines, methylamine and anilines. The reaction is also used in an intramolecular variant by the reaction of maleanilic acids to N-arylmaleimides.