Phosphorylation of dihydric phenols with amides of phosphorous acid

Phosphorylation of dihydric phenols with triamides of phosphorous acid was performed under different reaction conditions and using reactants taken in various ratios. The selectivity of the reaction depends on the presence of the solvent, its polarity, and, to a lesser degree, on the temperature.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2369–2370, September, 1996.     

糖尿病和硝化条件下胰岛素受体及底物酪氨酸磷酸化的研究

利用新颖的定量核磁共振(³¹P NMR)法和免疫印迹法研究了四氧嘧啶诱导的糖尿病状态下以及酪氨酸经过氧亚硝酸根供体SIN-1硝化条件下大鼠肝脏胰岛素受体(IR)的自磷酸化和受体底物1(IRS1)的磷酸化。结果表明,四氧嘧啶诱导的糖尿病大鼠肝脏中IR自磷酸化水平削弱了,硝化对大鼠肝脏中IR自磷酸化的影响依赖于SIN-1浓度,根据IRS1磷酸化位点基序设计的多肽的硝化完全抑制了其磷酸化,提示酪氨酸硝化可能干扰胰岛素磷酸化信号通路。     

Wittig Reaction: Role of Steric Effects in Explaining the Prevalent Formation of Z Olefin from Nonstabilized Ylides

Abstract

For understanding the mechanism involved in the Wittig reaction, it is important to know the factors which influence the stability of 1,2-oxaphosphetane intermediates with pentacoordinate phosphorus; in these intermediates, the steric factor plays a predominant role. Studying the Wittig reaction between nonstabilized ylides and different aldehydes, we noted that the stereochemical outcome driving toward Z-olefin formation was influenced only by different steric factors. The proposed mechanism differs from those previously reported because it underlines the fundamental role of the two cis/trans oxaphosphetane intermediates with the oxygen atom in equatorial position.     

Beryllium(II) Complexes with Bis(dimethylamino)phosphorylfluoride: A Multinuclear NMR (31P, 19F,and 9Be) Characterization in Solution

Complexes of beryllium chloride and nitrate with (Me₂N)₂P(O)F were characterized in solution by multinuclear NMR spectroscopy and in some cases by IR spectroscopy and conductimetry. ³¹P and ¹⁹F NMR spectra were informative of changes associated with complex formation revealing resonances consistent with different species in solution and suggest an equilibrium between these species in both beryllium derivatives. These compounds show narrow lines in the solution ⁹Be NMR spectra, indicative of a highly symmetric environment for beryllium. The presence of the different species was more pronounced in beryllium chloride complexes. The results are compared to those reported in the literature for hexamethylphosphoramide (HMPA).     

(4R,5R)-Bis(N,N-dimethylaminocarbonyl)-2-chloro-1,3,2-dioxaphospholane: A convenient reagent for control of enantiomeric composition of chiral alcohols by31P NMR spectroscopy

The use of enantiomerically pure cyclic chlorophosphite obtained by the reaction of PCl₃ withN,N,N′,N′-tetramethyldiamide of naturall-(+)-tartaric acid for analysis of the enantiomeric composition of chiral primary and secondary alcohols by³¹P NMR spectroscopy is considered. Translated fromIzvestiya Akademii Nauk., Seriya Khimicheskaya, No. 1, pp. 172–175, January, 1998.     

Study of the initial stages of alkoxo synthesis involving Ti(OBu)4 and cyclophosphites

The reactivities of cyclophosphite precursors in alkoxo syntheses involving titanium(iv) tetra(n-butoxide) were studied by ³¹P NMR and IR spectroscopy. 2-Diethylamido-4-methyl-1,3,2-dioxaphosphinane and 4-ethyl-2,6,7-trioxaphosphabicyclo[2.2.2]octane in benzene are inert toward Ti(OBu)₄. Gelation is accompanied by hydrolysis 2-diethylamido-4-methyl-1,3,2-dioxaphosphinane to give the corresponding hydrophosphoryl compound, while 4-ethyl-2,6,7-trioxaphosphabicyclo[2.2.2]octane remains intact during gelation.     

Effects of the phosphatidylglycerol head group on the binding of short dermcidin-derived peptides to the phospholipid membrane surface

Dermcidin (DCD) is a human peptide composed of 110 amino acids. When secreted into sweat, DCD undergoes postsecretory proteolytic processing to give the short antimicrobial peptides SSL-23 and SSL-25. As an initial phase of studies directed toward understanding the structural basis of the biological functions of these peptides, we chemically synthesized naturally occurring SSL-23 and SSL-25, as well as the artificial sequences SSL-21 and SSL-27, and analyzed their molecular interaction with bacterial and mammalian model surfaces. While dynamic-coating HPLC and CD spectroscopy revealed that the four SSL peptides selectively bound to a bacterial model membrane containing 1,2-dimyristoyl phosphatidylglycerol (DMPG) and underwent large structural changes, ³¹P NMR studies of the liposomes suggested that the attractive interaction between the peptides and DMPG did not lead to ion-pore formation or disruption of the model membrane. Our results strongly indicate that the SSL peptides express their selectivity to microorganisms by recognizing the head groups of their cell surface lipid.     

Tin(IV) Tetrachloride Complexes with Bis-(Dialkylamino)phosphoryl Fluoride: A Multinuclear (119Sn, 31P, 19F,and 1H) NMR Characterization in Solution

The two octahedral complexes SnCl₄·2(O)PF(NR₂)₂ (R = Me or Et) were prepared from reaction of SnCl₄ with the ligand (R₂N)₂P(O)F in anhydrous CHCl₃. The new adducts have been characterized by elemental analysis, IR, and multinuclear (¹¹⁹Sn, ³¹P, ¹⁹F, and ¹H) NMR spectroscopy. The NMR data show that the adducts exist in solution as a mixture of cis and trans isomers with markedly different proportions. When compared with previously described hexamethylphosphoramide (HMPA) and trimethylphosphate (TMPA) analogues, our results indicate that the cis isomer is the predominant species in solution. Low temperature ³¹P and ¹¹⁹Sn NMR spectra show that the compounds partially dissociate in dichloromethane.     

The preparation and analysis of fluoro-polyphosphates by F, P, 2D F-P HETCOR and 2D P-P COSY NMR

A complex mixture of fluoro-polyphosphates (FPPs) and polyphosphates was prepared by heating a mixture of NaF and sodium tripolyphosphate (STPP) at 600 °C in nitrogen atmosphere. Two-dimensional ³¹P-¹⁹F heteronuclear correlation spectroscopy (HETCOR) NMR was developed in identifying the atomic connection between F and P in the mixed FPPs. ¹⁹F, ³¹P and ³¹P-³¹P correlation spectroscopy (COSY) NMR methods were employed to identify the components of the mixture and measure the chain length of each FPP ingredient. NMR results clearly demonstrated that the mixture contains four kinds of fluoro-phosphates with different chain length of polyphosphate, which are monofluoro-phosphate (MFP), monofluoro-dipolyphosphate (MFDPP), monofluoro-tripolyphosphate (MFTPP) and difluoro-tripolyphosphate (DFTPP). Other phosphates and polyphosphates also were found in the mixture.     

Nuclear magnetic resonance of donor atoms as a tool for determination of the structure of platinum metal complexes in solutions

Data on the NMR spectroscopy of C, N, O, Si, P, and Sn donor atoms of platinum metal complexes in solutions are surveyed. The chemical shift of a donor atom mainly depends on the ligand in the trans-position (due to the trans-effect). The chemical shift of a donor atom on a particular coordinate of the complex (coordinate shift, CSh) is an attribute of this coordinate and can be used to identify such a coordinate in platinum metal complexes and to determine the structures of complexes. Based on the known data, CSh diagrams were composed for ¹H, ¹³C, ¹⁴N, ¹⁷O, ¹⁹F, ³¹P, and ¹¹⁹Sn. Examples of using the CShs for determining the structures of platinum metal complexes in solutions are presented.     

The reaction of thiophenoxide with amino-substituted chloro-cyclotriphosphazenes

In the present work, a series of aminocyclotriphosphazene containing sulfur group compounds have been synthesised and characterised by elemental analysis, mass (MS), ¹H and ³¹P NMR spectroscopies. The formation of thiophenoxy-substituted aminocyclotriphosphazenes could be explained by different mechanisms based on primary or secondary amino-substituted cyclotriphosphazenes. Compounds 3, 5 and 7 could be formed by a proton abstraction-chloride elimination and 9, 11 and 13 may be constituted both the S_N² and S_N¹ reaction mechanisms, respectively. These mechanisms are supported by the crystal structures of 5 and 13. Molecular and crystal structures of 5 and 13 have been characterised by X-ray crystallography. The structures of 5 and 13 are monoclinic and have space groups P2₁/n.     

Aldehyde Functionalization in the Tetrathiafulvalene Series: Towards New Highly Dimensional Organic Materials Derived from Sulfur-Rich Extended π-Donors

Abstract

We describe the synthesis of giant analogs of TTF. Their powerful donor ability has been characterized by thin layer cyclic voltammetry. An unprecedented type of 2-D cation-radical salt has been obtained by electrooxidation.     

Thermal transformations of α-H6P2Mo18O62·nH2O heteropolyacid

According to the ³¹P NMR spectroscopy, heteropolyacid (HPA) H₆P₂Mo₁₈O₆₂·nH₂O (P₂Mo₁₈), -isomer of the Dawson structure, transforms upon heating above 80 °C partially (up to 30%) to -isomer, in which both polar groups Mo₃O₁₃ of the heteropolyanion are turned by 60° around the N₃ axis, and partially to -isomer in which only one group is turned. The - and -isomers of P₂Mo₁₈ have been found for the first time. Their transformation into the -isomer occurs upon rehydration in one week in air and in 1 h in an aqueous solution. HPA P₂Mo₁₈ decomposes on heating up to 350 °C to HPA H₃PMo₁₂O₄₀ (PMo₁₂) and a previously unknown phase of the HPMo₆I₂₁ composition, which in its turn decomposes at 375 °C to molybdenyl phosphates and IiI₃. The PMo₁₂ decomposition occurs via two routes to form the same products at temperatures of 400 and 450 °C with corresponding exotherms of IiI₃ crystallization.     

P,O-Ligands. Complexes of tetraphenylmethylenediphosphine oxide with silver nitrate

The 1 : 1 and 1 : 2 complexes of AgNO₃ with Ph₂PCH₂P(O)Ph₂ were prepared and their structures were established by IR and ³¹P NMR spectroscopy and X-ray diffraction analysis. The crystal of the 1 : 1 complex consists of centrosymmetric dimers based on the ten-membered macrocycle AgOPCH₂PAgOPCH₂P. Each neutral ligand serves as a bridge between two silver ions, the latter being coordinated by the NO₃ group in the monodentate fashion. In the 1 : 2 complex, the dimeric structure is retained, but both NO₃ groups are replaced by the ligand molecules.     

Hydrogenation of CO2 to formic acid in the presence of the Wilkinson complex

Formic acid was synthesized in a high yield at room temperature in the presence of the Wilkinson complex and an excess of PPh₃. The catalytic properties of the rhodium complex depend strongly on the reaction conditions. The mechanism of the rhodium catalyst deactivation was studied by the kinetic method and ³¹P NMR spectroscopy. The methods for the stabilization of the rhodium catalyst were found.     

Structural properties of new spiro-1,3-propanediaminocyclotriphosphazene derivatives

New 1,3-propanediaminocyclotriphosphazene derivatives (7-17) were synthesized from the reactions of spiro-1,3-propanediaminocyclotriphosphazene, N₃P₃Cl₄[NH(CH₂)₃NH] (1) with the cyclopropanemethylamine (2), cyclohexylamine (3), pyrrolidine (4) cyclohexanol (5), cyclopropylmethanol (6). The structures of the novel compounds (7-17) were characterized by elemental analysis, mass spectrometry, ¹H and ³¹P NMR spectroscopy. The molecular structures of 8, 12 and 13 were determined by X-ray crystallography. The structures of all these three compounds are in the monoclinic crystal system; compounds 8 and 12 have the P21/c space group while compound 13 has the P21/n space group. The ring conformation of the cyclotriphosphazene and other external rings were investigated based on the X-ray crystal structures.     

31P NMR and HPLC Investigations of the Cyclophosphamide Metabolite,Phosphoramide Mustard

Abstract

Phosphoramide mustard (PM), a key active metabolite of the widely used anticancer drug cyclophosphamide (CP), can exist in several closely-related ionized, cyclized and substituted forms. We have developed a high pressure liquid chromatographic (HPLC) method for analysing serum concentrations of PM in order to relate these serum concentrations to toxicity and efficacy of treatment of CP. ³¹p NMR spectroscopy is used to verify the HPLC peak homology of the proposed PM peak.     

Triphenylethanediol-Derived 2-Chloro-1,3,2- dioxaphospholane: Synthesis,Structure, and Reaction with Chiral Alcohols

The reaction of (S)-1,1,2-triphenylethanediol (3) with phosphorus trichloride leads to the diastereoselective formation of (S _C,R _P)-2-chloro-1,3,2-dioxaphospholane (2). Its configuration has been determined by single crystal X-ray diffraction. When reacted with racemic secondary alcohols, diastereomeric phosphites are obtained, which display substantial shift differences in the ³¹P NMR spectra. Thus, chlorodioxaphospholane 2 can serve as derivatizing reagent for chiral secondary alcohols permitting to determine their enantiomeric excess.     

Products and kinetics of the thermal decomposition of (l-(−)-menthyl)[2,2′-methylene-bis-(4-methyl-6-tert-butylphenyl)] phosphite ozonide

Two conformers (chair, boat) of [l-(–)-menthyl)]-[2,2-methylene-bis-(4-methyl-6-tert-butylphenyl)] phosphite ozonide have been obtained by the low temperature ozonization (–80 °C) of [l-(–)-menthyl)]-[2,2-methylene-bis-(4-methyl-6-tert-butylphenyl)] phosphite. It was determined that decomposition of the ozonide is first order with the rate constant logk ₀ = (10.92±1.10)–(14.02±1.25)/gq ( = 2.303RT, kcal mol^–1), leading to [l-(–)-menthyl)]-[2,2-methylene-bis-(4-methyl-6-tert-butylphenyl)] phosphate and oxygen (including singlet oxygen). Conformational transitions (chair-boat) for [l-(–)-menthyl)]-[2,2-methylene-bis-(4-methyl-6-tert-butylphenyl)] phosphate have been registered by³¹P NMR spectroscopy.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1758–1761, October, 1994.This work was supported by Russian Foundation for Basic Research (Project No. 93-03-532l).