Preconcentration of gold,silver, palladium,platinum, and ruthenium with organophosphorus extractants

Extraction of noble metals in acid media with new tertiary phosphines and phosphine chalcogenides was examined. Tristyrylphosphine, tristyrylphosphine sulfide tris(2-phenylethyl)phosphine oxide, tris-(2-phenylethyl)phosphine sulfide, bis(2-phenylethyl)[2-(propylthio)ethyl]phosphine oxide, bis(2-phenylethyl)-[2-(butylthio)ethyl]phosphine oxide, and tris[2-(butylthio)ethyl]phosphine oxide were used as extractants. The suitability of the extractants for determination of Au, Ag, and Pd in rock and ore samples was elucidated.     

Reactions of Elemental Phosphorus and Phosphine with Electrophiles in Superbasic Systems: XIV.1 Phosphorylation of 2-Vinylnaphthalene with Elemental Phosphorus and Phosphines in the KOH-DMSO System

Elemental phosphorus (red or white) reacts with 2-vinylnaphthalene while heating at 90-96°C in the superbasic KOH-DMSO system to form 2-(2-naphthyl)ethylphosphine, 2-(2-naphthyl)ethylphosphinic acid, bis[2-(2-naphthyl)ethyl]phosphine, bis[2-(2-naphthyl)ethyl]phosphine oxide, and tris[2-(2-naphthyl)ethyl]phosphine oxide in a total yield of up to 40%. Selective conditions for preparing the tertiary phosphine oxide from white phosphorus and 2-vinylnaphthalene in 58% yield were found. Phosphine and (2-phenylpropyl)phosphine add to 2-vinylnaphthalene in the KOH-DMSO system to form, under certain conditions, corresponding secondary phosphines in high yields.     

Diastereoselective Synthesis of P-Chirogenic and Atropisomeric 2,2′-Bisphosphino-1,1′-binaphthyls Enabled by Internal Phosphine Oxide Directing Groups

Diphosphine ligands that merge both axial and P-centered chirality may exhibit superior or unique properties. Herein we report the diastereoselective introduction of P-centered chirality at the 2-position of the axially chiral 2′-(phosphine oxide)-1,1′-binaphthyl scaffold. A lithium–bromide exchange reaction of a 2-bromo-2′-(phosphine oxide)-1,1′-binaphthyl and treatment with dichlorophosphines followed by a nucleophilic organometallic reagent afforded unsymmetrical 2-phosphino-2′-(phosphine oxide)-1,1′-binaphthyls with binaphthyl axial chirality and one or two phosphorus stereocenters with a variety of P substituents. The final diastereomerically pure 2,2′-bisphosphino-1,1′-binaphthyls were obtained by reduction of the phosphine oxide directing group. Preliminary results demonstrated that a ligand with this hybrid chirality could induce higher stereoselectivity in the metal-complex-catalyzed asymmetric hydrogenation of a dialkyl ketone.     

Synthesis,Molecular, and Crystal Structure of Tris(2-carbamoylmethoxyphenyl)phosphine Oxide

Russian Journal of General Chemistry - New tripodal ligand, tris(2-carbamoylmethoxyphenyl)phosphine oxide, has been synthesized via the alkylation of tris(2-hydroxyphenyl)phosphine oxide with...     

Reaction of 3-thiolene 1,1-dioxide with PH-acids

The nucleophilic addition of 2-phenylethylphosphine, bis(2-phenylethyl)phosphine oxide, and bis(2-phenylpropyl)phosphine oxide to 3-thiolene 1,1-dioxide catalyzed by the KOH-DMSO system leads to bis(3-thioanil) (2-phenylethyl)phosphine oxide, bis(2-phenylethyl) (3-thianil)phosphine oxide, and bis(2-phenylpropyl) (3-thioanil)phosphine oxide, respectively.Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Sciences, 664033 Irkutsk. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1195–1198, September, 1998.     

Furfuryl-containing tertiary phosphine oxides and polymers based on some of them

The syntheses of dimethyl(furfuryloxymethyl)phosphine oxide (DPO), methylbis(furfuryloxymethyl)phosphine oxide (MPO), tris(furfuryloxymethyl)phosphine oxide (TPO), dimethyl(tetrahydrofurfuryloxymethyl)phosphine oxide (DTPO), methyl-bis(tetrahydrofurfuryloxymethyl)phosphine oxide (MTPO) and tris(tetrahydrofurfuryloxymethyl)phosphine oxide (TTPO) from dimethyl(chloromethyl)phosphine oxide, methyl-bis(chloromethyl)phosphine oxide, tris(chloromethyl)phosphine oxide and the furfuryl and tetrahydrofurfuryl sodium alkoxides via the Williamson reaction are reported. Phosphorus-containing furan polymers with reduced flammability are prepared by polymerizing MPO and TPO using p-toluenesulphonic acid as catalyst. The oxygen indexes of these polymers, as determined by ASTM D-2863, are 35.1 and 33.1% O₂, respectively; for the phosphorus-free polymer from difurfurylidene acetone, it is 23.0% O₂. It is shown that DPO can be used as an efficient fire-retardant for reducing the flammability of a polymer from difurfurylidenacetone.     

Optically active phosphine oxides. 5. P-chiral 2-aminoethyl phosphine oxides

Homochiral 2-aminoethyl phosphine oxides are expeditiously prepared by thermal addition of primary and secondary amines to (−)-(S)-methylphenylvinylphosphine oxide. Their transformation into optically active 2-aminoethyl phosphines and 2-aminoethyl phosphine sulphides is exemplified.     

A new phosphine-sulfides-to-phosphine-oxides exchange reaction

An unusual phosphine sulfide to phosphine oxide exchange reaction was found during the study of the annulation of (3,5-dimethylphenyl)-(2-hydroxy-2-methylpropyl)methylphosphine sulfide (3) using the mild cyclodehydration reagent methanesulfonic acid/phosphorus pentoxide.     

Studies on highly regio- and stereoselective fluorohydroxylation reaction of 3-aryl-1,2-allenyl phosphine oxides with Selectfluor

The fluorohydroxylation of allenyl phosphine oxides with Selectfluor in commercial MeCN without prior treatment or a mixed solvent of anhydrous MeCN (refluxed over CaH₂ and distilled before use) and 7.0 equiv of H₂O or MeNO₂/H₂O=10/1 afforded 2-fluoro-3-hydroxy-1(E)-alkenyl diphenyl phosphine oxides in moderate yields with very high regio- and stereoselectivities. The E-stereoselectivity is believed to be controlled by the phosphine oxide functionality. In the reaction of 3-(4-methoxyphenyl)-1,2-propadienyl diphenyl phosphine oxide, further fluorination on the electron-rich phenyl ring was also observed.     

Absolute configuration of tert-butyl-1-(2-methylnaphthyl)phosphine oxide

The enantiomers of tert-butyl-1-(2-methylnaphthyl)phosphine oxide 1 have been separated using a homemade HPLC column and an analytical gradient system. Vibrational absorption and circular dichroism spectra for both enantiomers have been measured in CD2Cl2 and CH2Cl2 solutions in the 2000-900 cm(-1) region. The fully relaxed potential energy surface of (S)-tert-butyl-1-(2-methylnaphthyl)phosphine oxide, obtained using the B3LYP functional with a 6-31G basis set, indicated two stable conformers with their populations in a approximately 2:1 ratio. The vibrational absorption and VCD spectra are predicted for these two conformers using the B3LYP functional with a 6-31G basis set. The comparison of predicted and experimental spectra indicated that (+)-tert-butyl-1-(2-methylnaphthyl)phosphine oxide is in the (S)-configuration. This assignment is supported by the ab initio prediction of positive optical rotation for the most stable conformer with an (S)-configuration and the nonequivalence sense of the tert-butyl group chemical shift observed in the 1H NMR spectrum of this enantiomer measured in the presence of (+)-(S)-mandelic acid as a chiral solvating agent.     

[2-(6,6-Dimethylbicyclo[3.3.1]hept-2-enyl)ethyl]-diphenylphosphine and phosphine oxide. Coordination properties and application in catalysis

[2-(6,6-Dimethylbicyclo[3.1.1]hept-2-enyl)ethyl]diphenylphosphine and the corresponding phosphine oxide, that hold promise as ligands in metal complex catalysis, were synthesized on the basis of (1R)-(-)-nopol. A Pd(II) bisphosphine complex is obtained on the basis of the synthesized phosphine. When the system [PdCl₂(COD)]-[2-(6,6-dimethylbicyclo[3.1.1]hept-2-enyl)ethyl]diphenylphosphine oxide is used as catalyst in the reaction of cyclohexa-1,3-diene with trichlorosilane, asymmetric induction occurs.     

Reaction of divinyl selenide with secondary phosphine chalcogenides

Under the conditions of free-radical initiation (AIBN, UV irradiation), divinyl selenide regioselectively reacts with secondary phosphine sulfides and phosphine selenides to afford, depending on the ratio of the reagents, mono- or diadducts mainly of the anti-Markownikoff structure. The conditions which allow obtaining the diadducts in up to 97% yield are found. By the example of 2-{[2-(diphenethylphosphoroselenoyl) ethyl]selanyl}ethyl(diphenethyl)phosphine selenide the diadducts were shown to react with aqueous hydrogen peroxide at 53–56°C to give vinyl(diphenethyl)phosphine oxide in 76% yield.     

TRI (2-PYRIDYL) PHOSPHINE,TRI(2-PYRIDYL) PHOSPHINE OXIDE,AND TRI (2-PYRIDYL) ARSINE METAL (II) PERCHLORATE COMPLEXES

Abstract

Metal(II) perchlorate complexes with the ligands tri(2-pyridyl)phosphine, tri(2-pyridyl)phosphine oxide, and tri(2-pyridyl)arsine have the composition [M(TPX)₂] (ClO₄)₂. Coordination occurs only through the nitrogens of the pyridines. In the case of Cu(II) and tri(2-pyridyl)phosphine oxide, two isomers were obtained. One isomer contains symmetrical tridentate tri(2-pyridyl)phosphine oxide ligands while the second isomer contains an unsymmetrical ligand. The unsymmetrical tri(2-pyridyl)phosphine oxide may be a bidentate ligand or a bridging tridentate. Weak axial interaction between a pyridyl group and a second Cu(II) ion is postulated in solution and may be present in the solid state.     

Reaction of diphenyl[2-(triethoxysilyl)ethyl]phosphine oxide with boron trifluoride etherate

Diphenyl[2-(trifluorosilyl)ethyl]phosphine oxide was synthesized by the reaction of diphenyl[2-(triethoxysilyl)ethyl]phosphine oxide with boron trifluoride etherate. As shown by the ¹H, ¹³C, ¹⁹F, ³¹P, ²⁹Si multinuclear NMR spectroscopy data, the silicon atom in the molecule is tetracoordinate. The absence of P=O→Si interaction in diphenyl[2-(trifluorosilyl)ethyl]phosphine oxide, as follows from the comparison of the calculated [GIAO B3LYP/6-311++G(2d,p)] and experimental δ(²⁹Si) and δ(³¹P) values, is due to the formation of complex with BF₃ by the phosphoryl oxygen.     

NMR spectrometric study of molecular complex formation of [60]- and [70]fullerenes with a number of phosphine oxides

Molecular complex formation between [60]- and [70]fullerenes with a series of phosphine oxides, namely, tri-n-octyl phosphine oxide, triphenyl phosphine oxide and tri-n-butyl phosphine oxide has been studied in CCl4 medium by NMR spectrometric method. Both [60]- and [70]fullerenes have been shown to form 1:1 adducts with the above series of phosphine oxides. Formation constants (K) for all the complexes have been determined from the systematic variation of NMR chemical shifts of specific protons of the donors in presence of [60]- and [70]fullerenes. Trends in the values of K suggest that [70]fullerene binds stronger with the phosphine oxides relative to [60]fullerene.     

Electrophilic and Nucleophilic Addition Reactions of α,β-Unsaturated Diphenylphosphoryl Compounds

Russian Journal of Organic Chemistry - Procedures were developed for the synthesis of diphenyl(prop-1-en-1-yl)phosphine oxide and cyclohex-1-en-1-yl(diphenyl)phosphine oxide by alkaline hydrolysis...     

Synthesis and structure of new 2-aryl-substituted pyrrolidines containing phosphine oxide group

2-Aryl-substituted pyrrolidines containing phosphine oxide group have been obtained by the reaction of P-(4,4-diethoxybutylaminomethyl)- P,P-di-p-tolylphosphine oxide with polyatomic phenols.     

PCl3- and organometallic-free synthesis of tris(2-picolyl)phosphine oxide from elemental phosphorus and 2-(chloromethyl)pyridine hydrochloride

In the superbase KOH/H₂O/toluene/phase-transfer catalyst system, 2-picolyl chloride, generated in situ from 2-(chloromethyl)pyridine hydrochloride, reacts with elemental phosphorus at 65–95?°C for 3?h to afford tris(2-picolyl)phosphine oxide in 50% yield. Single crystal X-ray analysis of the latter revealed one polymorph form of this tertiary phosphine oxide.     

Synthesis and resolution of 2-(diphenylphosphino)heptahelicene

Palladium catalysed Heck couplings have been applied to the two-step synthesis of a stilbene derivative bearing a diphenylphosphine oxide function which represents a suitable precursor for the photochemical generation of the corresponding [7]-helicene. After reduction of the phosphine oxide, resolution of the monodentate helical phosphine has been performed by means of the ortho-metallated (R)-1-(naphthyl)ethylamine-palladium complex. A ruthenium complex of (heptahelicen-2-yl)diphenylphosphine has also been prepared and fully characterized.     

新型N-P配体的合成、表征及其在氢转移反应中的应用

利用2,3-二(二苯膦氧基)-1,3-丁二烯与胺的迈克尔加成反应,合成了单胺基及环胺基改性的有机氧化膦,经有机硅烷还原,制备出胺基取代的膦配体,所得化合物经NMR及单晶X射线衍射分析.考察了所得配体与Ru(PPh3)3Cl2组成的催化体系在苯乙酮氧转移反应中的催化活性,发现氧化膦与Ru原位形成的催化剂比其还原态的三价膦组成的催化剂催化活性还高,二胺基取代的二氧化膦配体具有较高的催化活性,TON可达273.而采用先制备催化剂再催化反应时配体6的钌络合物催化活性TON可达352.