S. F. Malysheva

NUCLEOPHILIC ADDITION OF PHOSPHINE TO ARYL- AND HETARYLETHENES : A CONVENIENT SYNTHESIS OF BIS(2-ARYLALKYL)- AND BIS(2-HETARALKYL)PHOSPHINES

Abstract A number of secondary phosphines [RCH(R′)CH 2 ] 2 PH (R = aryl or hetaryl, R′ = H or Me) have been obtained in good yields by introducing phosphine at normal pressure into a mixture of the alkenes R(R′)CCH 2 , potassium hydroxide and dimethylsulfoxide.

Conformational analysis and stereochemical dependences of 31P–1H spin–spin coupling constants of bis(2-phenethyl)vinylphosphine and related phosphine chalcogenides

Theoretical energy‐based conformational analysis of bis(2‐phenethyl)vinylphosphine and related phosphine oxide, sulfide and selenide synthesized from available secondary phosphine chalcogenides and vinyl sulfoxides is performed at the MP2/6‐311G** level to study stereochemical behavior of their 31P–1H spin–spin coupling constants measured experimentally and calculated at different levels of theory. All four title compounds are shown to exist in the equilibrium mixture of two conformers: major planar s‐cis and minor orthogonal ones, while 31P–1 H spin–spin coupling constants under study are found to demonstrate marked stereochemical dependences with respect to the geometry of the coupling pathways, and to the internal rotation of the vinyl group around the P(X)‐C bonds (X = LP, O, S and Se), opening a new guide in the conformational studies of unsaturated phosphines and phosphine chalcogenides. Copyright

SUPERBASE-INDUCED GENERATION OF PHOSPHIDE AND PHOSPHINITE IONS AS APPLIED IN ORGANIC SYNTHESIS

Abstract A series of new direct reactions of red phosphorus (or white) with organyl halides, alkenes and acetylenes have been developed. Reactions occur in superbasic systems, such as alkali metal hydroxide-dipolar aprotic complexing solvent (DMSO, HMPA) or under phase-transfer conditions to afford earlier inaccessible triorganylphosphines and -phosphine oxides including unsaturated ones in good yields.

Synthesis of new secondary phosphine chalcogenides with bulky substituents from aryl(hetaryl)ethenes, red phosphorus, sulfur, and selenium

Phosphine generated along with hydrogen from red phosphorus and aqueous potassium hydroxide selectively reacts with aryl(hetaryl)ethenes (α-methylstyrene, 2-vinylnaphthalene and 5-vinyl-2-methylpyridine) in superbasic system KOH-DMSO(H2O) to give secondary phosphines. The latter are practically quantitatively oxidized by elemental sulfur or selenium (20–25°C, toluene, 0.5 h), to afford the hitherto unknown secondary phosphine chalcogenides with bulky arylalkyl pyridine and naphthyl substituents.

Diselenophosphinates. Synthesis and Applications

The last few years have seen a considerable expansion in research on the chemistry of diselenophosphinates (salts and esters of diselenophosphinic acids) due to the use of these compounds as effici...

Mechanical Properties of Ti–6Al–4V Titanium Alloy with Submicrocrystalline Structure Produced by Multiaxial Forging

A comparative investigation of mechanical properties of Ti–6Al–4V titanium alloy with coarse-grained (400 m), microcrystalline (10 µm) and submicrocrystalline (0.4 µm) structures in the temperature range 20–500°C has been carried out. The submicrocrystalline structure was obtained by multiaxial isothermal forging. The alloys with the coarse-grained and microcrystalline structures were used in a heat-strengthened condition. The microstructure refinement increases both the strength and fatigue limit of the alloy at room temperature by about 20%. The strength of the submicrocrystalline alloy is higher than that of the microcrystalline alloy in the range 20 - 400°C. Long-term strength of the submicrocrystalline specimens below 300°C is also considerably higher than that of the other conditions. However, the creep strength of the submicrocrystalline alloy is slightly lower than that of the heat-strengthened microcrystalline alloy already at 250°C. The impact toughness in submicrocrystalline state is lower especially in the samples with introduced cracks. Additional surface modification of submicrocrystalline alloy by ion implantation gives a considerable increase in the fatigue limit. Advantages of practical application of submicrocrystalline titanium alloys produced by multiaxial isothermal forging have been evaluated.

Synthesis of organic phosphines and phosphine oxides from elemental phosphorus and phosphine in the presence of strong bases

Data on the reactions of elemental phosphorus and phosphine with electrophilic reagents are described systematically and analyzed. These reactions occur in the presence of strong bases and yield primary, secondary, and tertiary phosphines and phosphine oxides.

Addition of secondary phosphines to N-vinylpyrroles

Abstract Secondary phosphines 1 – 3 react readily with N -vinylpyrroles 4 and 5 under radical initiation to give regiospecifically anti-Markovnikov adducts, diorganyl-2-(1-pyrrolyl)ethylphosphines 6a – d , highly reactive building blocks for organic synthesis, in 88–91% yields.

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.

Superbase-Assisted Addition of Phosphine to 1-Methoxy-4-vinylbenzene: Toward a Rare Family of Organic Phosphines

Abstract Phosphine reacts with 1-methoxy-4-vinylbenzene in the superbase suspension KOH-dimethylsulfoxide (70–100 °C, atmospheric pressure) to form regiospecifically anti-Markovnikov adducts, bis[2-(4-methoxyphenyl)ethyl]phosphine (1) and tris[2-(4-methoxyphenyl)ethyl]phosphine (2), representatives of rare arylalkylphosphines. The conditions for the selective preparation of phosphines 1 or 2 in 67% and 80% yields, respectively, have been elaborated. The phosphines have been oxidized with aqueous solution of H2O2, elemental sulfur, or selenium to afford the corresponding phosphine chalcogenides in good yields (95–99%). GRAPHICAL ABSTRACT