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.     

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.     

Simple unprecedented conversion of phosphine oxides and sulfides to phosphine boranes using sodium borohydride

A variety of phosphine oxides and sulfides can be efficiently converted directly to the corresponding phosphine boranes using oxalyl chloride followed by sodium borohydride. Optically active P-stereogenic phosphine oxides can be converted stereospecifically to phosphine boranes with inversion of configuration by treatment with Meerwein's salt followed by sodium borohydride.     

Nucleophilic addition of phosphine to 4-chlorostyrenes in the KOH-DMSO system

In the superbasic system KOH-DMSO (H₂O) at 60–75 °C (2–2.5 h, atmospheric pressure), 4-chlorostyrene and 4-chloro-α-methylstyrene add phosphine at the double bond to form 1: 1 and 2: 1 anti-Markovnikov adducts in 10–18% and 58–67% yields, respectively.     

Catalytic asymmetric deprotonation of phosphine boranes and sulfides as a route to P-stereogenic compounds

A comparison between phosphine boranes and sulfides in their catalytic asymmetric deprotonation using organolithiums and sub-stoichiometric amounts of (-)-sparteine has revealed superior catalytic efficiency in the phosphine sulfide deprotonation.     

Catalyst-free addition of secondary phosphine chalcogenides to pyrazolecarbaldehydes

1. Download : Download high-res image (84KB)
2. Download : Download full-size image

     

Catalytic reduction of acetylene in systems based on iron and sulfides

Conclusions The systems [Fe₄S₄ (n-BuS)₄]^2–-Na/Hg and Fe²⁺-S^2–-Na/Hg in methanol catalytically reduce acetylene under mild conditions.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No, 10, pp. 2394–2396, October, 1982.     

Mild reduction of chlorophosphine boranes to secondary phosphine boranes

A number of reducing reagents were assessed in the transformation of chlorophosphine boranes to secondary phosphine boranes. The efficiency of the process requires judicious matching between steric and electronic requirements of reductant and the substrate. The stereochemistry of the reduction was investigated by using a chiral precursor.     

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%).     

Michael-type addition of secondary phosphine oxides to (1,4-cyclohexadien-3-yl)phosphine oxides

Base-induced reaction between (1,4-cyclohexadien-3-yl)phosphine oxides and secondary phosphine oxides gives 3,4-bis(phosphinoyl)cyclohexenes and 2,3-bis(phosphinoyl)cyclohexenes through an in situ isomerization of one of the cyclohexadienyl double bonds and a subsequent Michael-type addition of the secondary phosphine oxide.     

Catalyst-free regio- and chemoselective addition of secondary phosphine oxides to isoquinolines

Russian Chemical Bulletin - Isoquinolines react with secondary phosphine oxides without catalyst (70–75 °C, 10–15 h, without solvent or in MeCN) to chemo- and regioselectively form...     

Air-induced anti-Markovnikov addition of secondary phosphine oxides and H-phosphinates to alkenes

[reaction: see text] Air (oxygen) induces the addition of secondary phosphine oxides and H-phosphinates to alkenes to selectively produce the corresponding anti-Markovnikov adducts in good to high yields. Mechanistic studies show that the addition probably proceeds via a radical chain mechanism.