M. V. Proskurnina

Reaction of Aromatic Aldehydes with Ammonium Acetate

By reaction of aromatic aldehydes with ammonium acetate a series of 1,2-diaryl-1,2-diaminoethanes and their derivatives was obtained. The mechanism of reaction was suggested and its principal stages were proved. Reactions with ammonium acetate of aromatic aldehydes containing ortho-substituents resulted in the corresponding 2,4,5-triaryl-4,5-dihydroimidazoles.

Regioselective synthesis of cis- and trans-2,4,5-triarylimidazolines and 2,4,5-triarylimidazoles from available reagents

Novel data were obtained concerning the reaction of aromatic aldehydes with ammonia. A preparative method for the synthesis of new substituted 1,3,5-triaryl-2,4-diazapenta-1,4-dienes was developed. These products are the starting reactants for syntheses of cis- and trans-2,4,5-triaryl-2-imidazolines and 2,4,5-triarylimidazoles.

Synthesis of novel МТ3 receptor ligands via an unusual Knoevenagel condensation

New 5-acetamido-substituted melatonin derivatives were efficiently synthesized in excellent yields via Knoevenagel condensation. The relative binding affinity of new synthesized compounds to MT3 receptor was tested via enzymatic assays and the X-ray structures of the most potent compounds were determined in complex with MT3.

Spectral and kinetic parameters of photoexcited complexes of albumin and indotricarbocyanine dye with phosphonate substituents

315 Complexation of indotricarbocyanine dyes with human serum albumin (HSA) is a principal factor determining the main parameters in the fluorescent identification of biomacromolecules in medical prac tice [1–3]. The efficiency of dyes in these methods is defined by impacts of fluorescence, intersystem cross ing, internal conversion, and photoisomerization [4]. Recently, we established the general regularities of complex formation and degradation of the photoexci tation energy in the complexes of HSA with indotri carbocyanine green (ICG) [5, 6] with two sulfo groups in its structure. These groups provide high solubility of ICG in aqueous solutions. The solubility of fluoro phores in the aqueous solutions can be attained also by introduction of other hydrophilic groups in the struc ture of cyanine dyes. This study deals with experimen tal investigation on complex formation and energy degradation of photoexcited complexes of albumin and the novel synthesized dye of indotricarbocyanine family ICG P with two ether phosphonate groups in the 3,3’ positions at the nitrogen atoms.

Electrophilic substitution in aromatic and heteroaromatic substrates by trichlorocyclopropenylium tetrachloroaluminate

Trichlorocyclopropenylium tetrachloroaluminate is an electrophilic reagent for the preparative introduction of a cyclopropenyl fragment into heteroaromatic and aromatic substrates.

Synthesis of advanced fluorescent probes — water-soluble symmetrical tricarbocyanines with phosphonate groups

A method for the synthesis of a series of water-soluble heptamethine indocyanine dyes containing a phosphonate group in the substituent bonded to the quaternary nitrogen atom of the indolenine moiety has been developed.

Reaction of Nitrous Oxide with Cyclopentadienyl Complexes of Cobalt, Rhodium, and Titanium

The reaction of nitrous oxide with some cyclopentadienyl compounds of cobalt, rhodium, and titanium was studied. The corresponding furans were obtained in low to moderate yields.

Ab initio study of molecular structure and internal rotation in methyldicyanophosphine and methyldiisocyanophosphine. The Raman spectrum of methyldicyanophosphine and its interpretation with the use of scaling ofab initio force fields

The equilibrium geometric parameters and structures of transition states of internal rotation for the molecules of methyldicyanophospine MeP(CN)2 and its isocyano analog MeP(NC)2 were calculated by the RHF and MP2 methods with the 6–31G* and 6–31G** basis sets. At the MP2 level, the total energy of cyanide is −35 kcal mol−1 lower than that of isocyanide and the barriers to internal rotation of methyl group for MeP(CN)2 and MeP(NC)2 are 2.2 and 2.7 kcal mol−1, respectively. For both molecules, the one-dimensionalab initio potential functions of internal rotation approximated by a truncated Fourier series were used to determine the frequencies of torsional transitions by solving direct vibrational problems for a non-rigid model. The Raman spectrum of crystalline MeP(CN)2 was recorded in the range 3500–50 cm−1. The vibrational spectra of this compound were interpreted by scalingab initio force fields calculated by the RHF and MP2 method. The vibrational spectrum of methyldiisocyanophosphine was predicted with the use of the obtained scale factors.

New phosphonate-substituted tricarbocyanines and their interaction with bovine serum albumin

New tricarbocyanine dyes with phosphonate groups (2, 3) were synthesized and their binding constants to bovine serum albumin (BSA) were determined. The binding constants of the synthesized tricarbocyanines and cardiogreen (1) (Kb ~ 105 M–1) are similar, indicating an insignificant contribution of the Coulomb interaction to the complex formation, which is determined by the polymethine chain interaction with BSA. The fluorescence lifetimes attest to the formation of two types of complexes: the lifetime of the dye complex with BSA with a major contribution (~80%) is 740–800 ps, and a lifetime of ~210 ps corresponds to the complex of dye aggregates with BSA.

Immobilized Phthalocyanine Aluminum Complexes in Synthesis of α–Aminophosphonates. Phosphorylation of Various Imines

GRAPHICAL ABSTRACT Abstract An aluminum phthalocyanine complex covalently bonded to the silica surface of mesoporous MCM-41 molecular sieve was successfully applied as a catalyst for hydrophosphorylation of various imines. The immobilized catalyst exhibited a high catalytic activity, stability, and reusability under various conditions for the synthesis of the wide range of α-aminophosphonates based on aminoacid ketimines, azines, hydrazones, semicarbazones, and oximes. The immobilization of the phthalocyanine to the walls of MCM-41 was performed by the reaction of phthalocyanine tetracarboxylic acid chloroanhydride with MCM-41 premodified by 3-(aminopropyl)-triethoxysilane (APTES).The catalytic performance of the novel AlPc-MCM-41 for hydrophosphorylation was compared with that of the same unsupported complexes.