Reactions of Bis(chloromethyl)phosphinic(-Phosphinothioic) Chlorides with Silylated Carbamates and Trimethylsilyl N-Trimethylsilylacetimidoate

Bis(chloromethyl)phosphinic chloride reacts with trimethylsilyl methylcarbamate in benzene in the presence of a base to give trimethylsilyl bis(chloromethyl)phosphinate. The same reaction performed without a solvent and in the absence of a base yields trimethylsilyl bis(chloromethyl)phosphinate and bis(chloromethyl)phosphinic anhydride. Reaction of bis(chloromethyl)phosphinic chloride with trimethylsilyl diethylcarbamate yields N,N-diethylbis(chloromethyl)phosphinic amide. The reaction of bis(chloromethyl)phosphinic (-phosphinothioic) chlorides with trimethylsilyl N-trimethylsilylacetimidoate was studied.     

A novel method for the separation of bis(alpha-hydroxyalkyl)phosphinic acid diastereoisomers via formation of novel cyclic phosphinic acids

The reaction of aromatic and aliphatic aldehydes with hypophosphorus acid under microwave irradiation was examined. The reaction gave a mixture of a racemic pair of bis(alpha-hydroxyalkyl)phosphinic acids and acetal derivatives from the corresponding bis(alpha-hydroxyalkyl)phosphinic acids of meso-stereochemistry in good yield. The difference in solubility in organic solvents due to polarity allowed us to readily separate these compounds. This method constitutes an easy, rapid, and good-yielding preparation and separation of bis(alpha-hydroxyalkyl) phosphinic acid diastereoisomers from simple starting materials using microwave irradiation.     

The Structures of Bis(3-aminophenyl)phosphinic Acid and Its Derivatives in Solutions

According to IR and ¹⁵N NMR spectroscopy data, bis(3-aminophenyl)phosphinic acid exists in the molecular form in the DMSO and DMF solutions. The molecular and ionic forms are in equilibrium in the solutions of triethylammonium salt of bis(3-aminophenyl)phosphinic acid in DMSO and DMF.     

The first separation and stereochemical determination of bis(α-hydroxyalkyl) phosphinic acids diastereoisomers

A separation of bis(α-hydroxyalkyl) phosphinic acid diastereoisomers is described. A novel method for the determination stereochemistry of bis(α-hydroxyalkyl) phosphinic acid diastereoisomers has been developed. The stereochemistry of one diastereoisomer was confirmed after converting to the corresponding methyl ester using trimethyl orthoformate.     

Phosphorylation of Ethyl Urethane,Urea, and Acetamide with Bis(chloromethyl)phosphinic Chloride in the Presence of Potassium Carbonate

Bis(chloromethyl)phosphinic chloride reacts with urethane to give phosphorylated urethane, whereas with urea and acetamide the final reaction product is bis(chloromethyl)phosphinic anhydride.     

Experimental and Quantum Chemical Studies of 2-Phosphinylphenol Derivatives

Carbon-oxygen bonds ortho to a phosphoryl group in triarylphosphine oxides undergo cleavage when the oxides are either fused with potassium hydroxide or treated with potassium tert-butoxide in refluxing toluene, presumably through a nucleophilic addition-elimination mechanism. Thus, bis(2-hydroxyphenyl)phenylphosphine oxide is produced along with the expected 2-phenoxyphenyl(phenyl)phosphinic acid from 10-phenyl-10H-phenoxaphosphine 10-oxide. The latter starting material is also produced, together with bis(2-hydroxyphenyl)phenylphosphine oxide, when bis(2-methoxyphenyl)phenylphosphine oxide is fused with potassium hydroxide. Fusion of bis(2-methoxyphenyl)phenylphosphine oxide with sodium hydroxide, however, yields 2-hydroxyphenyl(phenyl)phosphinic acid. Ab initio quantum chemical studies confirm that the downfield ³¹P chemical shift that is observed in 2-phosphinylphenols is due to hydrogen bonding to the phosphoryl group.     

Synthesis and characterization of new platinum(II) phosphinate complexes

The syntheses of platinum(II) complexes of bis(dimethylphosphinylmethylene)amine and bis(aminomethyl)phosphinic acid were investigated. In the case of bis(dimethyl-phosphinylmethylene)amine the reaction with K₂[PtCl₄] yields the potassium amino-trichloroplatinate K[PtCl₃L] (L?=?bis(dimethylphosphinylmethylene)amine), which was characterized by multinuclear (¹H, ¹³C, ³¹P, and ¹⁹⁵Pt) NMR spectroscopy in solution. Bis(aminomethyl)phosphinic acid reacts with K₂[PtCl₄] under strictly controlled pH conditions to give colorless crystals of the cisplatin analog K[PtCl₂L′] (L′?=?bis(aminomethyl)phosphinate). This complex was characterized by multinuclear NMR spectroscopy in solution as well as by single-crystal X-ray diffraction in the solid state. The bis(aminomethyl)phosphinate coordinates to platinum via both amino functions, thus acting as a chelating ligand.     

Synthesis of bis(Aminomethyl)-phosphinic Acids via a Mannich Reaction

N,N,N'N'-Tetrasubstituted bis(aminomethyl)-phosphinic acids were synthesized from iminoacids, paraformaldehyde and aqueous phosphinic acid via a Mannich reaction.     

The structures of bis(3-aminophenyl)phosphinic acid and its derivatives in the solid state

Russian Chemical Bulletin - According to IR spectroscopy data, solid bis(3-aminophenyl)phosphinic acid has a zwitterionic structure.     

Photodegradation and by-products identification of commercial extractant Cyanex 302

The photodegradation of the organothiophosphorous extractant Cyanex 302 and purified bis(2,4,4-trimethylpentyl)monothiophosphinic acid dissolved in toluene was carried out in photoreactor using UV–Vis light irradiation. Possible degradation products were identified with the assistance of FT-IR, LC/MS/MS and GC/MS. The catalytic influence of zinc(II), copper(II) and cobalt(II) ions and the presence of trace values of water and aqueous solutions of sulphuric acids on the photodecomposition of Cyanex 302 were studied. The results demonstrated that the presence of trace amounts of water causes mainly the degradation of bis(2,4,4-trimethylpentyl)monothiophosphinic acid with the simultaneously fourfold increase in bis(2,4,4-trimethylpentyl)phosphinic acid concentration. The shaking with aqueous solution of sulphuric acids results in the decrease in the photodegradation probably by blocking of OH radical. Metal ions also affect the degradation causing the increase in bis(2,4,4-trimethylpentyl)phosphinic acid concentration. The photodegradation was also carried out in open atmosphere under sunlight and the obtained results were compared with those obtained in a Heraeus photoreactor.     

Reaction of the Na salts of 2-amino-6-methyl-4-hydroxypyrimidine with bis(bromomethyl)phosphinic acid

The reaction of the Na salts of 2-amino-6-methyl-4-hydroxypyrimidine and bis(bromomethyl)phosphinic acid gave 3,5-dioxo-1,2,3,4,5,8-hexahydro-7-methyl-1,8-diaza-4a-azonia-3-phosphanaphthalene-3-olate, whose structure was determined by X-ray diffraction study. The molecule has a bipolar structure, in which a positive charge is delocalized on the guanidine fragment and a negative charge is on the phosphinic acid fragment.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1125–1128, June, 1995.     

Selective separation of minor actinides and lanthanides using aromatic dithiophosphinic and phosphinic acid derivatives

A new extractant for the separation of actinide(III) and lanthanide(III) cations, bis(o-trifluoromethylphenyl) phosphinic acid (2) was synthesized. The synthetic route employed mirrors one that was employed to produce the sulfur containing analog bis(o-trifluoromethylphenyl) dithiophosphinic acid (1). Classic radiochemical methods and absorbance spectroscopy were used to study the coordination chemistry of the Am-dithiophosphinic acid and Am-phosphinic acid complexes.     

A mild and efficient catalyst for the Beckmann rearrangement, BOP-Cl

BOP-Cl (bis(2-oxo-3-oxazolidinyl)phosphinic chloride) was found to be very active as the first organophosphorus catalyst (1-5 mol % loading) for the Beckmann rearrangement of various ketoximes to the corresponding amides in anhydrous acetonitrile at refluxing temperature.     

Synthesis and properties of bis [N-Alkyl(aryl)-aminomethyl]phosphinic acids

Conclusions Reaction of primary aliphatic and aromatic amines with bischloromethylphosphinic acid yielded a series of bis(N-alkyl(aryl)aminomethyl)phosphinic acids and the methacroylamides of several of them were obtained.Translated from Izvestiya Akademii Nauk SSSR, Seriya Kkimicheskaya, No. 8, pp. 1860–1862, August, 1968.     

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...     

A novel double deprotection-peptide cyclisation procedure and its application to the synthesis of analogues of the cyclic tetrapeptide HC-toxin.

A hydroxide-mediated Fmoc/methyl ester double deprotection procedure followed by an improved bis(2-oxo-3-oxazolidinyl)phosphinic chloride (BOP-Cl) cyclisation reaction are reported. This novel methodology was applied to the synthesis of three new HC-toxin analogues.     

Component analysis of the commercial metal extractant, Cyanex 302, by GC-MS.

The composition of the commercial reagent Cyanex 302 was investigated by GC-MS. Mass spectrometric studies allowed us to confirm that bis(2,4,4-trimethylpentyl)monothiophosphinic acid is the major compound and that a considerable amount of tris(2,4,4-trimethylpentyl)phosphine oxide is also present. The study also revealed that the extractant has three minor components. These were identified as bis(2,4,4-trimethylpentyl)phosphinic acid, bis(2,4,4-trimethylpentyl)phosphine oxide and bis(2,4,4-trimethylpentyl)dithiophosphinic acid. The mass spectra of these compounds are discussed and some fragmentation processes are postulated.     

Kinetics of the alkaline hydrolysis of bis(chloromethyl)phosphinic esters

Conclusions The kinetics of the hydrolysis of bis (chloromethyl)phosphinic esters was investigated in KOH medium at 10 and 25°. The rate constants are correlated with the steric constants of the leaving groups.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 923–924, April, 1967.     

A Method for Preparing Phosphinic Acids from Hypophosphites: III. Synthesis of α-Hydroxy Phosphinic Acids

A one-pot method is proposed for preparing unsymmetrical -hydroxy phosphinic acids from ammonium hypophosphite. Bis(trimethylsilyl) phosphonites formed in situ on addition of bis(trimethylsilyl) hypophosphite to activated unsaturated compounds are brought without isolation into the Abramov reaction with an aldehyde or ketone. A series of new -hydroxy phosphinic acids are obtained.