Tertiary Phosphine Oxides in Reaction with Benzaldehyde

Symmetrical and unsymmetrical tertiary phosphine oxides containing benzyl and 5-chloro-2-thienyl radicals stereoselectively react with benzaldehyde in the sodium amide-THF system to form the E isomers of 1-organyl-2-phenylethene and diorganylphosphinic acids in high yields. Triethyl, tris(2-phenyl- ethyl)-, and tris[(4-methoxyphenyl)methyl]phosphine oxides under the above-mentioned conditions do not react with benzaldehyde.     

Noncatalytic Regio- and Stereoselective Addition of Secondary Phosphines to Cyanoacetylenic Alcohols

Secondary phosphines regio- and stereoselectively add to 4-hydroxy-4-methyl-2-pentynenitrile, a typical and available representative of cyanoacetylenic alcohols, without catalyst at room temperature (THF, 3 h) to form (Z)-3-[dialkyl(aryl) phosphino]-4-hydroxy-4-methyl-2-pentenenitriles in 80–85% yields. These compounds relate to a new class of functionalyzed phosphines, promising ligands for the design of metal-complex catalysts.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 4, 2005, pp. 552–555.Original Russian Text Copyright © 2005 by Arbuzova, Shaikhutdinova, Gusarov, Nikitin, Mal’kina, Sukhov, Bogdanova, Trofimov.     

First representative of phosphorylated formic acid hydrazides with three P—C bonds: synthesis and addition to the phosphorylated 4-methylenequinones

Russian Chemical Bulletin - Diethylphosphinylmethanehydrazide, the first representative of the phosphorylated formic acid hydrazides with three P—C bonds was obtained, which can exhibit...     

Reactions of Elemental Phosphorus and Phosphine with Electrophiles in Superbasic Media: XI.1 Phosphorylation of 4-Methoxybenzyl Chloride with Elemental Phosphorus and Phosphine

4-Methoxybenzyl chloride reacts with elemental (red or white) phosphorus under the conditions of phase-transfer catalysis (concentrated aqueous KOH, dioxane, benzyltriethylammonium chloride, 85-90°C, argon) to give as major product tris(4-methoxybenzyl)phosphine oxide in up to 45% yield. With white phosphorus at lower (70°C) temperature this reaction yields mainly bis(4-methoxybenzyl)phosphine oxide. Phosphine reacts with 4-methoxybenzyl chloride in superbasic KOH-DMSO suspension, and under definite conditions bis(4-methoxybenzyl)phosphine oxide is predominantly formed.     

Thermodynamic parameters of the single-stage dehydrogenation of isopentane to isoprene

From the results of experiments with platinum-containing catalysts operating in the steady mode, adiabatic changes in temperature in the course of 2-metylbutane dehydrogenation to monoolefins and isoprene were calculated. Dehydrogenation of 2-methylbutane and its mixtures with methylbutenes in the 500–600°C temperature range was simulated with varying the concentrations of 2-methylbutane, methylbutenes, hydrogen, and water, the conversion, and the selectivities with respect to both isoprene and methylbutenes. The most suitable reactor designs with intermediate heating of the reaction mixture were suggested.     

Deoxygenation of some α-dicarbonyl compounds by tris(diethylamino)phosphine in the presence of fullerene C60

The reactions of such cyclic α-diketones as acenaphthenequinone, aceanthrenequinone, and N-alkylisatins, with hexaethyltriaminophosphine in the presence of the fullerene C(60), lead to the formation of methanofullerene derivatives under mild conditions. This process proceeds via deoxygenation of the dicarbonyl compound by the P(III) derivative and is likely to involve the intermediate formation of α-ketocarbenes. The structure of some methanofullerenes has been confirmed by NMR and XRD. The electrochemical behavior of the methanofullerenes was also investigated.     

Backward timelike Compton scattering to decipher the photon content of the nucleon

The European Physical Journal C - We consider invisible neutrino decay $$\nu _H \rightarrow \nu _l + \phi $$ in the ultra-relativistic limit and compute the neutrino anisotropy loss rate relevant...     

Stereochemistry of Seven-Membered Heterocycles: XLII. A Theoretical Study of Stereochemistry of H Complexes Formed by Conformationally Nonuniform 2-R-1,3-Dioxacyclohept-5-enes with Some Proton Donors

According to semiempirical AM1 calculations, the stability of the boat and twist forms of 2-R-1,3- dioxacyclohept-5-enes depends on the size of substituents at the acetal carbon atom. The twist form gives diastereomeric H complexes with chloroform and methanol of the cis and trans structure, containing monocentered hydrogen bonds, whereas the chair conformation preferably forms complexes with a two-centered hydrogen bond. Based on theoretical data (_{O H}, H, geometry of complexes), the specific features of H complexes of the conformers in electrophilic addition and cycloaddition were revealed. Considerable preferableness of the exo attack of the diastereotopic double bond in the H complex having the chair form is due to the steric accessibility of the exo side, whereas in the complexes of the twist form the facial selectivity is appreciably lower.     

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.     

Study of the reactivity of organonickel sigma-complexes towards nitriles

The reactivity of organonickel sigma-complexes of type [NiBr(Ar)(bpy)], where Ar = 2,6-dimethylphenyl (Xyl), 2,4,6-trimethylphenyl (Mes), 2,4,6-triisopropylphenyl (Tipp), 2,4,6-tricyclohexylphenyl (Tchp), bpy = 2,2´-bipyridine, towards nitriles (acetonitrile, propionitrile, chloroacetonitrile, benzonitrile) has been investigated. This reaction leads to imines by formation of new carbon—carbon bond between aromatic fragment and nitrile group C≡N.