Vol 86, No 3 (2016)

The features and selected applications of the homolytic organophosphorus synthesis based on the addition of phosphorous acid and its acid esters to unsaturated compounds, discovered by A.N. Pudovik in 1954.

Phosphoric acid derivatives containing chiral Betti base fragment were synthesized by reacting racemic and enantiopure N-Boc-protected 1-(α-aminobenzyl)-2-naphthols with diethyl chlorophosphate followed by deprotection.

A facile method of synthesis of functionally substituted P(IV) derivatives―dialkyl(diaryl)(2-hydroxybenzyl) phosphine oxides―by the reaction of 2-ethoxy-2,3-dihydro[d][1,2]oxaphosphole 2-oxide with organomagnesium compounds, which allows wide variation of substituents on the phosphorus atom was developed.

Reactions of 1-chloroacetyloxindole and 1-chloroacetylisatin with some secondary amines, Girard’s reagent T and thiourea were studied. All investigated reactions proceeded via cleavage of the acyl group to form 3-substituted isatin or oxindole derivatives.

The state of the art of chloral applications in the chemistry of tricoordinate phosphorus derivatives has been analyzed. The highly stereoselective reaction of 4,4,5,5-tetramethyl-2-(2-oxo-1,2-diphenylethoxy)-1,3,2-dioxaphospholane with chloral has been shown to afford a caged phosphorane with the phosphorus–carbon bond, 1,1-tetramethylethylenedioxy-3,4-diphenyl-6-trichloromethyl-2,5,7,1-trioxaphosphabicyclo- [2.2.1^1,4]heptane. Structure of the phosphorane and its hydrolysis product, 2-(1-hydroxy-2,2,2-trichloroethoxy)- 4,4,5,5-tetramethyl-2-oxo-1,3,2-dioxaphospholane, has been elucidated by X-ray diffraction analysis.

Lucensomycin, tetraene macrolide antibiotic, has been chemically modified with dialkyl(diaryl) phosphites under conditions of the Todd–Atherton reaction. The reaction has yielded the corresponding dialkyl-(diaryl) amidophosphate derivatives of the antibiotic. Physico-chemical properties of the prepared derivatives as well as their toxicity and antifungal activity towards a series of pathogenic Candida yeast-like fungi have been studied. The automated decision-making information system for selection of highly efficient antibiotics has been described.

Conformational analysis of eight-membered P,N-heterocycles (P₂^NR₂^R') in the solution has been performed by means of NMR spectroscopy and quantum chemical calculations. The equilibrium of the С₂-symmetrical (crown, major) and С_s-symmetrical (chair-boat, minor) forms of the compounds has been revealed, the transition barriers being of about 12 kcal/mol. The presence of an aromatic substituent at the nitrogen atom significantly shifts the equilibrium towards the dominating form.

Salicylaldehyde derivatives containing sterically hindered phenol fragments were synthesized. The compounds obtained are capable to offer protection against UV radiation.

The system chlorine dioxide–dimethylformamide in combination with or without a catalytic amount of MoCl₅, CeCl₃, ZrOCl₂, or VO(acac)₂ induces oxidative chlorination of a number of bicyclic terpene alcohols and vicinal diols. 2α-Chloropinan-3-one, 3α-chloro-10β-pinan-4-one, 5α-chloro-3α-hydroxycaran-4-one, 5β-chloro-3β-hydroxycaran-4-one, and 4α-chloro-2α-hydroxypinan-3-one were thus synthesized in good preparative yields.

A simple and effective general method of synthesis of α- and β-diphenylphosphorylated secondary alkanols by the reduction of the corresponding phosphorylalkanones with NaBH4 was developed. The extraction properties of the resulting phosphorylalkanols Ph₂P(O)(CR₂)_nCH₂CH(OH)Me (n = 0, 1; R = H, Me) were studied in the recovery of f-elements (La^III, Nd^III, Ho^III, Yb^III, U^VI, Th^IV) from nitric acid solutions into chloroform and compared with those of both related phosphorylketones and known extractants (n-BuO)₃PO, (n-C₈H₁₇)₃PO, and Ph₂P(O)CH₂C(O)N(n-Bu)₂.

Reactions of dibenzylideneacetone and cyclic cross-conjugated dienones with hexacarbonylmolybdenum(0) and bis[tricarbonyl(cyclopentadienyl)molybdenum(0)] afforded the corresponding complexes with η²-(C=C),η²-(C=O) coordination of the diketone to metal center, regardless of the ligand structure and initial molybdenum compound. The reactivity of the multidentate ligands may change as a result of coordination.

Surface modification of the luminescent silica nanoparticles doped with Tb(III)–p-sulfonatothiacalix[ 4]arene complex was carried out using a series of nitrogen/oxygen-containing trialkoxysilanes. It was found that groups capable of nonspecific interactions on the surface of the nanoparticles cause a significant decrease in their colloidal stability. The chromophore moieties in the modifiers were found to quench the luminescence of the nanoparticles. The surface modification of the nanoparticles is responsible for the change in the mechanism of luminescence quenching in the presence of copper(II) ions due to decreased accessibility of luminophores to the quencher.

A series of novel substituted pyridine derivatives have been synthesized via the reaction of 3-indole carboxaldehyde with 3-aminoacetophenone. The products structures have been elucidated from elemental analysis as well as IR, ¹H NMR, ¹³C NMR, and MS spectroscopy data. All the synthesized compounds have shown anticancer activity against HEPG2 and MCF-7 in vitro; some of them have exhibited the in vivo activity.

A new cyanide-bridged heterobimetallic Fe(III)–Mn(II) complex {[MnL][FebpdBrb]} [FebpdBrb]_n· 2nH₂O has been synthesized by using pyridinecarboxamide trans-dicyanideiron as the building block. The X-ray diffraction analysis has revealed the one-dimensional infinite structure of the complex consisting of the alternating [Mn(L)]²⁺ and [Fe(bpdBrb)(CN)₂]^– units forming a cyanide-bridged cationic polymeric chain, with [Fe(bpdBrb)(CN)₂]^– as the free anions. The antiferromagnetic coupling between the neighboring Fe(III) and Mn(II) ions through the bridging cyanide group has been revealed. The magnetic coupling constant has been determined as of J =–3.17 cm^–1.

Silica-supported perchloric acid (HClO₄/SiO₂) was used to catalyze the synthesis of tetraazamacrocyclic complexes of Co(II), Ni(II), Cu(II), and Zn(II) from the corresponding metal chlorides, nitrates, or acetates, isatin, and benzene-1,2-diamine in ethanol. The use of HClO₄/SiO₂ as catalyst allowed the reaction to be performed under stirring at room temperature instead of traditional reflux and completed in two hours. The synthesized complexes were characterized by molar conductance and magnetic susceptibility measurements, IR, electronic, ¹H NMR, and mass spectra, and thermogravimetric and X-ray powder analyses. On the basis of these data, six-coordinate octahedral geometry was proposed for all complexes. The synthesized complexes were also tested for antimicrobial activity.

Synthesis, spectroscopic characterization, theoretical and antimicrobial studies of Ca(II), Fe(III), Pd(II), and Au(III) complexes of amoxicillin (amox) antibiotic drug are presented in the current paper. Structure of 1: 1 (metal: amox) complexes were elucidated on the basis of elemental analyses, and IR, Raman, ¹H NMR, and electronic spectral data. According to molar conductance measurements the complexes had electrolyte nature. Amoxicillin reacted with metal ions as a tridentate ligand coordinated with metal ions via–NH₂,–NH, and β-lactam carbonyl groups. The complexes were formulated as [Ca(amox-Na)(H₂O)]·Cl₂·4H₂O (1), [Fe(amox-Na)(H₂O)₃]·Cl₃·3H₂O (2), [Pd(amox-Na)(H₂O)]·Cl₂ (3), and [Au(amox-Na)(H₂O)]·Cl₃ (4). Kinetic thermodynamic parameters (E*, ΔS*, ΔH*, and ΔG*) were calculated based on the Coats–Redfern and Horowitz–Metzger methods using thermo gravimetric curves of TG and DTG. Nanosize particles of amoxicillin complexes have been studied by XRD, SEM, and TEM methods. Theoretical studies of the synthesized complexes have been performed.