Nataliya A. Chernysheva

Trivinylphosphine and trivinylphosphine chalcogenides: stereochemical trends of 31P1H spin–spin coupling constants†

A combined theoretical and experimental study of the stereochemical behavior of 31P1H spin–spin coupling constants has been performed in the series of trivinylphosphine and related trivinylphosphine oxide, sulfide and selenide. Theoretical energy‐based conformational analysis of the title compounds performed at the MP2/6‐311G** level reveals that each of the four compounds of this series exists in the equilibrium mixture of five true‐minimum conformers, namely s‐cis‐s‐cis‐s‐cis, s‐cis‐s‐cis‐gauche, syn‐s‐cis‐gauche‐gauche, anti‐s‐cis‐gauche‐gauche and gauche‐gauche‐gauche, which were taken into account in the conformational averaging of 31P1H spin–spin couplings calculated at the second‐order polarization propagator approach/aug‐cc‐pVTZ‐J level of theory. All 31P1H spin–spin coupling constants involving phosphorus and either of the vinyl protons are found to demonstrate a marked stereochemical dependences with respect to the geometry of the coupling pathway and internal rotation of the vinyl group around the PC bond which is of major importance in the stereochemical studies of the unsaturated phosphines and phosphine chalcogenides. Copyright

Regio- and stereospecific addition of phosphines to cyanoacetylenes

Abstract Primary and secondary phosphines add regio- and stereospecifically to phenylcyanoacetylene and 4-hydroxy-4-methylpent-2-ynenitrile under mild conditions to form corresponding functionalized secondary and tertiary phosphines of Z -configuration in 70–91% yield. According to ESR and UV data, the addition of primary phosphines to phenylcyanoacetylene involves a single electron transfer process.

Reaction of divinyl selenide with secondary phosphine chalcogenides

Divinyl telluride reacted with 2 equiv of diphenylphosphine sulfide in the presence of AIBN as radical initiator (63–68°C) to give the corresponding anti-Markovnikov adduct in 68% yield with high regioselectivity. Treatment of the addition product with aqueous hydrogen peroxide at room temperature afforded 71% of vinyldiphenylphosphine oxide. Radical addition of diphenylphosphine selenide to divinyl telluride (AIBN, 63–68°C) led to the formation of 1,1,3,3-tetraphenyldiphosphoxane 1,3-diselenide in 82% yield.

Green synthesis of tertiary alkylselanylphosphine chalcogenides via catalyst- and solvent-free addition of secondary phosphine chalcogenides to vinyl selenides

Secondary phosphine sulfides and phosphine selenides react with vinyl selenides under mild conditions (80–82°C, without catalyst and solvent) to form regioselectively functionalized anti-Markovnikov adducts in high yield. GRAPHICAL ABSTRACT

One-pot atom-economic synthesis of Se-[alkyl(aryl)sulfanylethyl]diselenophosphinates from vinyl sulfides, secondary phosphines and elemental selenium

Alkyl(or aryl)vinyl sulfides react chemo- and regioselectively with secondary phosphines and elemental selenium (1.1:1:2 molar ratio) at 100°C (1,4-dioxane, 1.5 h) to form functionalized Se-[1-(organosulfanyl)ethyl]diselenophosphinates in 83–94% yields.

Synthesis of tris(organylthioethyl)phosphines and their derivatives on the basis of the reaction of phosphine with vinyl sulfides

Phosphine generated from the red phosphorus in the system KOH-H2O-toluene adds regio- and chemoselectively to vinyl sulfides under radical initiation conditions with the formation of tris(2-organylthioethyl)phosphines, which are easily oxidized by elemental sulfur and selenium to the corresponding phosphine sulfides and phosphine selenides in 54–78% yield. The obtained adducts are split when treated with sodium amide in THF to give trivinylphosphine and trivinylphosphine chalcogenides.

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.

Reaction of vinyl sulfoxides with sodium sulfide and polysulfides

Sodium sulfide and polysulfides readily (50–55°C, 3 h, aqueous medium) react with alkyl vinyl sulfoxides to afford bis(alkylsulfinylethyl)sulfides and-polysulfides in up to 75% yield. Under comparable conditions the reaction of divinyl sulfoxide with sodium sulfide proceeds by the mechanism of addition-cyclization and results in 1,4-dithiane-1-oxide and 1,4-oxathiane-4-oxide. Microwave activation of the studied reactions allows to increase their rate and efficiency.

An expedient synthesis of methyl vinyl sulfide from dimethyl disulfide and acetylene

Dimethyl disulfide reacts with acetylene under atmospheric pressure in basic reductive systems MOH (M=Na, K)–N2H4 · H2O–N-methylpyrrolidone and Na2S · 9H2O–N2H4 · H2O–N-methylpyrrolidone to form methyl vinyl sulfide in up to 79% yield.

Non-catalyzed addition of secondary phosphine chalcogenides to divinyl chalcogenides under solvent-free conditions

ABSTRACT Secondary phosphine chalcogenides, R2PX (R═(CH2)2Ph, Ph; X = S, Se), react with divinyl chalcogenides, (CH2═CH)2Y (Y = S, Se, Te), at the 2:1 molar ratio (80–82°C, 56–80 h) in the absence of both catalysts (initiators) and solvents to quantitatively afford the corresponding anti-Markovnikov diadducts. Even at the equimolar reactant ratio, the diadducts are the major products, though monoadducts are also formed. When Y = Te, vinylphosphine chalcogenides and metal Te are obtained, thus showing that divinyl telluride behaves as the vinylating agent. GRAPHICAL ABSTRACT