Phenyl­phosphinic acid

The crystal structure of the title compound, C₆H₇O₂P, shows continuous hydrogen-bonding chains in the x direction, with a P—O⋯O=P distance of 2.513 (3) Å.     

Double Arbuzov Reaction. Synthesis of Bis(ω-cyanoalkyl)phosphinic Acids

Russian Journal of General Chemistry - A general method for the synthesis of symmetric bis(ω-cyanoalkyl)phosphinic acids from ammonium hypophosphite was proposed. The reaction of...     

Cu-catalyzed arylation of phosphinic amide facilitated by (±)-trans-cyclohexane-1,2-diamine

Cu-catalyzed cross coupling between phosphinic amides and aryl halides was accomplished for the first time by using(±)-trans- cyclohexane-1,2-diamine as the ligand.This reaction provided a novel approach for synthesizing arylated phosphinic amides.Both kinetic measurement and theoretical calculation indicated that phosphinic amides were much less reactive than amides by about 10 times in Cu-catalyzed cross coupling.     

Synthesis of phosphinic acids on the basis of hypophosphites: IV. Synthesis of pseudo-γ-glutamylglycine and its enantiomers

A new method for construction of pseudopeptide molecules is proposed, exemplified by the synthesis of [3-amino-3-(hydroxycarbonyl)propyl][2-(hydroxycabonyl)ethyl]phosphinic acid (I) (pseudo--glutamylglycine), starting from ammonium hypophosphite. Enzymatic synthesis using immobilized penicillamidase allowed preparation of the enantiomers of acid I.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 8, 2004, pp. 1273–1278.Original Russian Text Copyright © 2004 by Ragulin.For communication III, see [1].This revised version was published online in April 2005 with a corrected cover date.     

An efficient one-pot synthesis of bis(α-aminoalkyl)phosphinic acids,phosphorus-isosteric analogues of HIV protease inhibitors

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Synthesis and in vitro antioxidant evaluation of new bis(α-aminoalkyl)phosphinic acid derivatives

Diamines were added to arylaldehydes in ethanol, which resulted in corresponding diimines. Novel bis-1-aminophosphinic acid compounds were synthesized through the interaction of diimines and hypophosphorous acid. The new compounds were characterized by elemental analyses, FT-IR and ¹H, ¹³C and ³¹P NMR techniques. The in vitro antioxidant activity of the newly synthesized compounds were measured and found to exhibit significantly higher antioxidant activity than the standard.     

Effective Mutual Separation of Europium(Ⅲ) from Gadolinium(Ⅲ) by Using ODS Modified with Bis(l,l,3,3-tetramethylbutyl) phosphinic acid——Extraction Chromatography in HGlyc Acid-HN03 System

It is well known that lanthanides is one of the most difficult groups of elements to be separated in the periodical table because of the so-called lanthanide contraction. Among lanthanides,the 4f orbital of gadolinium(Ⅲ) is half-filled——4f⁷,such a stable configuration leads to the effects from coordination field weaker on gadolinium than that on the adjacent lanthanides, and the stabilities of gadolinium(Ⅲ) complexes somewhat lower than those of europium(Ⅲ) in some cases.     

Study of direction of cyclization of malonodithioamides as a method of investigation of reactivity of α-diazothioacetamides

The reaction of malonothioamides with benzene-sulfonyl azide and 2-azido-3-ethylbenzthiazolium tetrafluoroborate gave amides of 2-diazothiomalonic acid, which underwent cyclization to a mixture of 5-N-R-amino-1,2,3-thiadiazole-4-carbothioamides and 5-amino-1,2,3-thiadiazole-4-N-R-carbothioamides. The ratio of the isomeric thiadiazoles formed in this reaction is the same as in the reactions of 2-diazo-2-cyanoacetamides, 5-amino-1,2,3-thiadiazole- and 5-mercapto-1,2,3-triazole-4-carboxamides with P₄S₁₀ and of 5-amino-1, 2,3-thiadiazole-4-carbonitriles with H₂S; it is characteristic of the influence of substituents on the reactivity of -diazothioacetamides. It was found that the cyclization of the diazo compounds is accelerated when electron-acceptor substituents are attached to the nitrogen atom of the carbothioamide group.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1106–1112, August, 1992.     

Synthesis of a Pair of Derivatives of N-Methylpyrrole Polyamide

A pair of derivatives of tetrameric N-methylpyrrole polyamide were synthesized in order to develop a new method for the study of interaction of the polyamide derivatives with DNA. Indole acetic acid and nicotinic acid were introduced to the polyamide in the synthesized compound, which showed an expected red shift in the UV spectrum. These compounds may function as a potential tool in the detection of the polyamide binding to DNA.     

Structure of Potassium of Undecatungstomononickelosilicate

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Analysis of Significance of Unite Examination of AFP and DNA Polymorphism of P3 Promoter of IGF-ⅡGene

The DNA of P3 promoter region of IGF-Ⅱ gene was obtained by means of PCR technique. The examination of DNA polymorphism by restriction endonuclease BstE Ⅱ and the examination of AFP by bioluminescence immunoassay technique were carried out. The results have a significant difference(P<0.005). But the positive rate of AFP is higher than that of DNA polymorphism. The experimental result shows that the change of the DNA polymorphism of IGF-Ⅱis not the only carcinogenic factor. The suggested unite examination is the best method for the diagnosis of the primary hepatocellular carcinoma.     

Kinetics of tautomerization of 1,3,4,7-tetramethylisoindole

The kinetics of transformation of 1,3,4,7-tetramethylisoindole(1)to 1,3,4,7-tetramethyl-1H-isoindole(2)in water or in deuterium oxide at various pH or pD at 25℃ were measuredspectrophotometricalty.The results indicated that the transformation of 1 to 2 could be promotedby acid and base.From the solvent isotope effects and the fact that the 1-position of isoindole nucleusis electron-rich,the mechanism of this transformation is suggested.     

Synthesis of Related Compounds of Carotenoid

类胡萝卜素是一类奇特的色素，由高等植物和微生物光化学合成，作为防止单线氧通过光敏反应产生危害的必要基团，类胡萝卜素最近受到了关注。类胡萝卜素联于富勒烯上，既可大大增加在可见光区域光诱导电子转移的有效吸收断面，又可抑制富勒烯敏化单线氧的危害能力。合成了类胡萝卜素的相关化合物，报道的某些反应条件先进且简洁。     

Analysis of Significance of Unite Examination of AFP and DNA Polymorphism of P3 Promoter of IGF- Ⅱ Gene

IntroductionTheinnatecharacterofthesolidcarcinomaistheresultthatcellgrowthgetsoutofcontrol.Itsbasicreasonconsistsintheabnormalityofthetumorgene .SomeonethinksthatthegeneofIGF Ⅱisoneofthecancergenesofthe primaryhepatocellularcarcino ma[1] ,andalsothinkstheoverexpressionofthegeneofIGF Ⅱtakesplaceintheearlierperiodofthepri maryhepatocellularcarcinoma ,whichmaybetheear lierdiagnosticnormofprimaryhepatocellularcarcino ma .ThefurtherresearcheshavedemonstratedthattheactivationofIGF Ⅱ genepromo…     

Peculiarities of dissociative ionization of alkylcyclopentadienyl nitrosyl π-complexes of nickel

The decomposition of alkylcyclopentadienyl nitrosyl -complexes of nickel, (C₅H₄R)(NO)Ni (R=H, Et,i-Pr, CH₂Ph), under the action of electron impact has been studied. The nature of the nitrosyl ligand has been shown to be the factor determining the main fragmentation pathway which involves the abstraction of an NO molecule. The effect of the nature of the ligand on the ability of the molecular ion (C₅H₄R)LNi⁺ (L=C₅H₄R, C₅H₅, C₃H₅, NO) to rearrange with hydrogen atom migration from one ligand to another has been considered. The structure of the alkyl group R determines a competing fragmentation pathway involving cleavage of the -C-C bond with respect to the cyclopentadienyl ring in the substituent.Translated fromIzyestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1985–1988, November, 1993.     

2D NMR Investigation of Dynamic Equilibrium of Tautomers of Gossypol

Gossypol was obtained as an yellow platelike crystal with m.p. 210-214o . In CDCl3 there were three tautomers of gossypol: I aldehyde, II lactol,III ketal , in equilibrium .Their total H 1 NMR spectra were assigned by means of 1D and 2D NMR techniques including 1H-1H cosy , DEPT , HMQC (1H Detected Heteronuclear Multiple Quantum Coherence) and HMBC (1H Detected Heteronuclear Multiple Bond Connectivity) experiments . This paper first reported that we took use of the 2D NMR t…     

Analysis of Chemical Incredients of Angelica Sinnesis——Analysis of Non-Volatile Constituents of Roots

In the present investigation,the non-volatile constituents of Danguei (Tang-Kuei) roots of Gansu origin [Angelica sinensis (Oliv.) Diels] were analyzed and thirty seven organic constituin s were also identified,fifteen of which have not been recorded in literature before,including a new optically active compound named as Angelicide and an antibiotie,Brereldin A.By plasma emission spectrometry,thirteen minor elements were also detecled     

TPSR Studies of the Activation of

TPSR　Studies　of　the　Activation　of　...     

Dependence of the basic properties of meso-nitro-substituted derivatives of β-octaethylporphyrin on the nature of substituents

Spectrophotometric titration is used to study the basic properties of a series of porphyrins with a continuously increasing degree of macrocycle deformation resulting from the introduction of strong electron-withdrawing substituents: 2,3,7,8,12,13,17,18-octaethylporphyrin (I), 5-nitro-2,3,7,8,12,13,17,18-octaethylporphyrin (II), 5,15-dinitro-2,3,7,8,12,13,17,18-octaethylporphyrin (III), 5,10,15-trinitro-2,3,7,8,12,13,17,18-octaethylporphyrin (IV), and 5,10,15,20-tetranitro-2,3,7,8,12,13,17,18-octaethylporphyrin (V). It is found that the values of logK _b (total basicity constants) obtained for the investigated compounds consistently diminish with an increase in the number of meso-substituents: 11.85 (I) > 10.45 (II) > 10.31 (III) > 10.23 (IV) > 9.56 (V). It is shown that two opposing factors, the steric and electronic effects of the substituents, change the basic properties of the above series of compounds.