Radical addition of secondary phosphine sulfides and selenides to vinyl tellurides

The regiospecific addition of secondary phosphine sulfide and phosphine selenide to alkyl vinyl tellurides proceeds under radical initiation (AIBN, 65–70 °C, 2.5–3.5 h) to afford the anti-Markovnikov adducts, (2-alkyltellanylethyl)phosphine chalcogenides, in 86–99% yields.     

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 © 2009 John Wiley & Sons, Ltd.     

An Expedient Access to γ‐Ketophosphine Chalcogenides via the Chemo‐ and Regioselective Addition of Secondary Phosphine Chalcogenides to β,γ‐Ethylenic Ketones

γ‐Ketophosphine chalcogenides, precursors for plethora of novel functionalized phosphine chalcogenides and phosphines, are synthesized by chemo‐ and regioselective addition of secondary phosphine chalcogenides to β,γ‐ethylenic ketones under catalyst‐ and solvent‐free conditions (80–100°C, 8–70 h) in excellent yields. The straightforward superbase‐catalyzed synthesis of starting β,γ‐ethylenic ketones from ketones and acetylenes insures the expedient access to the target γ‐ketophosphine chalcogenides.     

Straightforward Solvent‐Free Synthesis of Tertiary Phosphine Chalcogenides from Secondary Phosphines,Electron‐Rich Alkenes,and Elemental Sulfur or Selenium

A series of tertiary phosphine sulfides and selenides have been synthesized in excellent yields (88‐99%) via a three‐component reaction between secondary phosphines, electron‐rich alkenes (styrene, vinyl chalcogenides), and elemental sulfur or selenium, proceeding under solvent‐free conditions (80‐82°C, 4–44 h). The interaction occurs via initial oxidation of secondary phosphines with elemental sulfur or selenium followed by noncatalyzed anti‐Markovnikov addition of the generated R₂P(E)H (E = S, Se) species to alkenes to afford the corresponding adducts with high chemo‐ and regioselectivity.     

Directed synthesis of tertiary phosphine chalcogenides with pyridine and hydroxy functions

Secondary phosphine chalcogenides react with pyridine-2-, pyridine-3-, and pyridine-4-carbaldehydes under mild noncatalytic conditions (22–43°C, 1–8.5 h) to form in 81–98% yield functional tertiary phosphine chalcogenides containing pyridine and hydroxy functions.     

A new method for the synthesis of diorganylvinylphosphine oxides

Diorganylvinylphosphine oxides were synthesized in 31–38% yields on heating (50°C) diorganylphosphine oxides with vinyl sulfoxides or divinyl sulfone in the presence of KOH. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1895–1896, October, 1997.     

Atom-Economic Synthesis of Tris[2-(organylthio)ethyl]phosphine Oxides from Phosphine and Vinyl Sulfides

Abstract

Phosphine, generated from elemental phosphorus in the system KOH-toluene-H₂O, reacts with vinyl sulfides under free radical conditions (AIBN, dioxane, 65–70°C, atmospheric pressure) to form regiospecifically tris[2-(organylthio)ethyl]phosphines, which are readily oxidized in air to corresponding tris[2-(organylthio)ethyl]phosphine oxides.     

Chemoselective noncatalytic addition of secondary phosphine chalcogenides to citral

Addition of secondary phosphine oxides, phosphine sulfides and phosphine selenides to 3,7-dimethyl-2,6-octadienal (citral) (48–50°C, THF, argon) proceeds exclusively to the aldehyde group giving rise to new polyfunctional tertiary phosphine chalcogenides with diene and hydroxyl moieties in high preparative yield (up to 80%).     

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.     

Chlorination of secondary phosphine chalcogenides with carbon tetrachloride in the absence of bases

The interaction of bis(2-phenylethyl)phosphine sulfide, bis(2-phenylethyl)phosphine selenide and bis[2-(2-phenyl)propyl]phosphine selenide with carbon tetrachloride under heating (80°C, 8–20 h) leads to the formation of the corresponding chlorophosphine chalcogenides with the yield of 80–90%.

     

Synthesis of oxazolidinylphosphine chalcogenides from aminoethyl vinyl ethers

N-(2-Vinyloxyethyl)phosphinothioamides and -phosphinoselenoamides prepared by oxidative cross-coupling of 2-vinyloxyethylamine with secondary phosphine chalcogenides undergo thermal (75–100 °C) cyclization into the corresponding 3-(diorganylchalcogenophosphoryl)-2-methyl-1,3-oxazolidines in 80–90% yields.     

Oxidative metal‐free cross‐coupling of secondary phosphine chalcogenides and benzenediols: Synthesis of phosphinochalcogenoic O‐diesters

Benzenediols react with 2 equiv of secondary phosphine chalcogenides in the CCl₄–Et₃N system under mild conditions (50–52°C, 1.5–13 h) to give phosphinochalcogenoic O‐diesters in 62–91% isolated yields. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:322–328, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21020     

Nucleophilic addition of secondary phosphine sulfides to divinyl sulfoxide and divinyl sulfone

Secondary phosphine sulfides readily undergo addition to divinyl sulfoxide and divinyl sulfone in the presence of KOH (THF, 20–22°C, 1 h) with regiospecific formation of bis[2-(diorganylthiophosphoryl)-ethyl] sulfoxides and sulfones. A dramatic increase in the electrophilicity of the double bond in the monoadduct suggests transfer of the electron-acceptor effect of the thiophosphoryl group directly though space, due to its donor-acceptor interaction with the polarized S-O bond. It was demonstrated by the example of divinyl sulfoxide that, when performed with equimolar amounts of reactants and a weaker base (LiOH), the reaction can be stopped at the stage of formation of the monoadduct.     

Unusual Course of the Reaction of Allyl Phosphine Oxides with the Grundmann Ketone

This article describes efficient preparation of isomeric allyl phosphine oxides possessing a protected cyclohexanediol fragment. Their base-catalyzed interconversions are examined and reactions with the Grundmann ketone provide an adduct containing the rearranged vinyl phosphine oxide moiety, instead of 19-norvitamin D₃ analogs, the expected products of the Horner–Wittig process.     

Modified copolymers of bifunctional vinyl ethers with methyl vinyl sulfide as active matrices of solid superbases

Reactive linear and crosslinked copolymers of diethylene glycol divinyl ether and ethylene glycol vinyl glycidyl ether with methyl vinyl sulfide have been synthesized in the presence of 2,2′-azobis(isobutyronitrile) (2%, 60 °C, 45–55 h) in ∼53% yield. The hydrolyzed at the residual vinyloxy and epoxy groups and oxidized at the methylthio groups copolymers upon treatment with KOH afford alkoxide (complex) and crown-like superbases. They are capable of catalyzing the acetone ethynylation, as well as the prototropic isomerization of methyl propargyl ether to allenyl methyl ether and vinylation of ethylene and diethylene glycols with acetylene.     

First Examples of the Atherton–Todd‐Like Reaction in the Absence of Bases

Oxidative cross‐coupling between secondary phosphine chalcogenides and alcohols or phenols proceeds in CCl₄ medium at 80–82°C to afford phosphinoсhalcogenоic O‐esters in up to 92% yield. These couplings represent first examples of the Atherton–Todd‐like reaction occurring in the absence of bases.     

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.     

Synthesis of glucosamine vinyl ether derivative and its deuterated analog

The use of calcium carbide (in the presence of H₂O) as a source of acetylene in the reaction with methyl 2-amino-4,6-O-benzylidene-2-deoxy-β-d-glucopyranoside under superbasic conditions (KF, KOH, DMSO, 130 °C, 3 h) led to the corresponding vinyl ether in 78% yield. The vinylation does not affect other reaction centers. Replacement of water with deuterium oxide in the reaction mixture gave a stable deuterated analog of this vinyl ether in 72% yield. The one-step isotopic enrichment was practically quantitative (isotopic purity >96%). Introduced deuterium atoms can be used as a convenient label in further transformations.

     

Expedient Route to Chalcogenophosphinates with Glucose Moieties via Todd–Atherton‐Like Coupling between Secondary Phosphine Chalcogenides and Diacetone‐d‐Glucose in the CCl4/Et3N System

Secondary phosphine chalcogenides react with diacetone‐d‐glucose (DAG) in the system CCl₄/Et₃N (70°C, 4–24 h) to afford DAG chalcogenophosphinates in up to 79% yield, thus paving a short way to optically active chalcogenophosphinates with glucose moieties. As an example, a mild regioselective hydrolysis (70°C, aqueous MeCOOH) of DAG bis(2‐phenylethyl)selenophosphinate) obtained leads to monoacetone‐d‐glucose bis(2‐phenylethyl)selenophosphinate.     

Vinylation of hydroxy-containing cyclic formaldehyde acetals with acetylene

Nucleophilic addition of alcohols having cyclic acetal fragments to acetylene smoothly occurs under relatively mild conditions (KOH, 100–125°C, 1–2 h, initial acetylene pressure 11–12 atm) to give the corresponding vinyl ethers in 80–83% yield.