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Synthesis of pre-organized oligofunctional ligands based on ortho-methyl-tetra-C-naphthyl-resorcinarene existing in the chair conformation was carried out. By selective modification derivatives dif...

Mixed acyl dihydroquercetin derivatives were synthesized for the first time. The cytotoxicity of the acylation products of this flavonoid was determined against cultures of HeLa tumor cells and murine fibroblasts.

Starting from 2,2-di-(p-hydroxyphenyl)propane and phenylphosphonic acid tetraethylamide we have prepared the first oligoarylenephosphonites with spatially separated phosphorus functionalities. We have studied the principal chemical properties of these compounds. We have shown the capacity of oligoarylenediphosphonites to coordinate with transition metals through one or all phosphorus atoms with formation of mono- and oligo complexes. We have found that monocomplexes can undergo degenerated metallotropic rearrangements.

To study the chemical nature of the acid catalysis of amides oftrivalent-phosphorus acids (ATPA) alcoholysis the most important procedural problems have been solved. Simple and efficacious techniques for the purification of original ATPA from amine hydrohalides have been worked out. A precise and reliable way has been chosen to control the residual amount of amine hydrohalides in ATPA having been subjected to the various purification procedures. The nature of the dependence of alcoholysis rate constants for ATPA of different structures on the aminehydrohalide concentration has been established. The general acid catalysis was established using the Bronsted equation, so that the process includes the formation of a catalytic H-complex incorporating substrate and catalyst on the whole. Amides P(III) of different types treated with anhydrous hydroborofluoric acid readily form the corresponding P-protonated salts. The conversions of corresponding products of complete protonation have been investigated. The structure of P-protonated salt 23 has been studied by means of X-ray analysis.

The hydrolytic activity of ethriol phosphite and triphenyl phosphite in the p-xylene/water two-phase system was studied by the31P NMR method. It was shown that the rate of hydrolysis can be controlled by varying the pH of the aqueous phase. Hydrolysis of triphenyl phosphite is much slower than that of ethriol phosphite in the tested pH range. Coordination of ethriol phosphite with a rhodium carbonyl complex completely suppresses its hydrolysis.

Complexes of cuprous phenylacetylenide (CPA) were obtained with various amides of phosphorous acid, which are cubane-like tetramers (PhC=CCuL)4. Copper is coordinated at the phosphorus atom in these complexes. The coordination shift of the ligands in the31P NMR spectra are directly dependent on the electronegativity of the heteroatoms at phosphorus.

1. The chemical shift of the OH group of the phenol monomer was determined. 2. In phenolinert solvent systems a monomer-trimer equilibrium is observed, with the exception of low concentrations of phenol (~0.03 mole fraction). 3. The chemical shift of the signal of the OH group of the phenol trimer depends on the temperature. 4. The solvent CCl4 is not entirely inert. 5. The constants and thermodynamic parameters of association in systems of phenol and in inert solvent were determined. 6. In all the systems studied the enthalpy remains constant, while the entropy varies from system to system.

The δ (C13) values of the ring carbon atoms for the C13-NMR spectra of 3-methylsydnone and 3-methylsydnoneimine, described for the first time, are compared with the values calculated by the Karplus-Pople method. The interrelationship between the δ(C13) values of conjugated carbocycles, heterocycles, alkenes, and a number of carbonyl-containing compounds and the effective charges of the corresponding carbon atoms calculated by the complete neglect of differential overlap (CNDO/2) method is analyzed thoroughly.

1. The thermodynamic parameters of the reactions for the formation of the complexes of p-chloro- and p-fluorophenol with a number of oxygen-containing donors (pyridine N-oxide, phosphoryl derivatives, triethylamine) were determined. The thermodynamics of these reactions obeys the linear relation between ΔH° and ΔS° that is general for donor-acceptor complexes. 2. The chemical shifts of the hydroxyl protons of the monomeric p-chloro- and p-fluorophenol molecules and of their complexes were determined. Based on an analysis of these shifts it was concluded that the formation of the hydrogen bond O-H... D leads to a decrease in the electron density on the hydrogen atom, which is greater the higher the energy of the H bond (in the energy range from 0 to 12 kcal/mole).

1. m-Bromo-α,β-difluoro-β-chlorostyrene was synthesized and the conditions for the analytical and preparative separation of the cis and trans isomers were determined. They were isolated with a purity of 99.8% as were the isomers of the previously synthesizedα, β- difluoro-β-chlorostyrene. 2. The structure of the isomers was confirmed by NMR, NQR, and IR spectroscopies.