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%).     

Reaction of divinyl selenide with secondary phosphine chalcogenides

Under the conditions of free-radical initiation (AIBN, UV irradiation), divinyl selenide regioselectively reacts with secondary phosphine sulfides and phosphine selenides to afford, depending on the ratio of the reagents, mono- or diadducts mainly of the anti-Markownikoff structure. The conditions which allow obtaining the diadducts in up to 97% yield are found. By the example of 2-{[2-(diphenethylphosphoroselenoyl) ethyl]selanyl}ethyl(diphenethyl)phosphine selenide the diadducts were shown to react with aqueous hydrogen peroxide at 53–56°C to give vinyl(diphenethyl)phosphine oxide in 76% yield.     

One-pot synthesis of ultra-branched mixed tetradentate tripodal phosphines and phosphine chalcogenides

Ultra-branched mixed tetradentate tripodal phosphines and phosphine chalcogenides have been synthesized by the exhaustive regioselective addition of secondary phosphines, phosphine sulfides and phosphine selenides to available tris(4-vinylbenzyl)phosphine oxide under free-radical conditions (UV irradiation or AIBN) in good to excellent yields.     

Reaction of secondary phosphine chalcogenides with diallylamine

Diphenyl- or bis(2-phenylethyl)phosphine sulfides and -phosphine selenides react with diallylamine under radical initiation (UV or AIBN) to afford the corresponding diadducts and tetrahydropyrrolylmethyl phosphine chalcogenides. The yield and the ratio of the products depend on the structure of the starting secondary phosphine chalcogenides.     

Reaction of secondary phosphine chalcogenides with 2,2,2-trichloroacetaldehyde

The nucleophilic addition of secondary phosphine chalcogenides to 2,2,2-trichloroacetaldehyde proceeds under mild noncatalytic conditions (12–25dgC, 15–90 min) with the formation of functional tertiary phosphine chalcogenides, containing hydroxy groups in up to 98% yield. Using the method of concurrent reactions the reactivity of secondary phosphine chalcogenides in this reaction was shown to decrease in the order: (PhCH₂CH₂)₂P(O)H ≫ (PhCH₂CH₂)₂P(S)H > (PhCH₂CH₂)₂P(Se)H, and the secondary bis[2-(2-pyridyl) ethyl]-phosphine oxide was more reactive than bis(2-phenethyl)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%.

     

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.     

Atom-sparing synthesis of tertiary diphosphine dichalcogenides from acetylenes and secondary phosphine chalcogenides

Secondary phosphine oxides and phosphine sulfides react with acetylene, methylacetylene, and phenylacetylene in the presence of strong bases (KOH-DMSO, KOH-THF) by the mechanism of double nucleophilic α,β-addition to form tertiary diphosphine dioxides and diphosphine disulfides in high yield (up to 97%).     

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.     

Adducts of Rh2[MTPA]4 with some phosphine chalcogenides: nature of binding and ligand exchange

Adducts of four phosphine chalcogenides with the chiral dirhodium complex ([Rh-Rh]) were investigated by variable-temperature 1H and 31P NMR spectroscopy in order to compare their properties as axial ligands. Whereas the selenide (1) and the sulfide (2) are strong ligands with electrostatic attraction and, in addition, a significant orbital (HOMO-LUMO) interaction, the phosphine oxide compounds (P=O) bind primarily via electrostatic attraction and are relatively weak donors. Moreover, the overall bond strength in these adducts depends on steric congestion around the P=O group.     

Quantum-chemical calculations of NMR chemical shifts of organic molecules: II. Influence of medium, relativistic effects, and vibrational corrections on phosphorus magnetic shielding constants in the simplest phosphines and phosphine chalcogenides

The influence of solvent nature, relativistic effects, and vibrational corrections on the accuracy of calculation of ³¹P chemical shifts of the simplest phosphines, phosphine oxides, phosphine sulfides, and phosphine selenides was studied. Consideration of the above factors at the stage of both geometry optimization and calculation of magnetic shielding constants was found to appreciably improve the accuracy of calculation of ³¹P NMR chemical shifts in the series of phosphines and phosphine chalcogenides.     

Reaction of imidazole series aldeydes with bis[2-(2-pyridyl)ethyl]-phosphine chalcogenides: Synthesis of polyfunctional heterocyclic systems

The nucleophilic addition of bis[2-(2-pyridyl)ethyl]phosphine sulfide and bis[2-(2-pyridyl)-ethyl]phosphine selenide to 2-formyl-1-organylimidazoles and benzimidazoles occurs efficiently without catalysis at room temperature to give functionalized heterocyclic compounds containing imidazole, benzimidazole, and pyridine rings and also chalcogenophosphoryl and hydroxyl groups. Dedicated to Professor A. Pozharskii on his 70th jubilee Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1669–1675, November, 2008.     

Oxidative coupling of hydroxy- or aminoazobenzenes with secondary phosphine chalcogenides: Towards new media-responsive molecular switches

One or two chalcogenophosphinate groups were introduced to the azobenzene scaffold via the oxidative cross-coupling reaction of 4-amino-, 4-hydroxy- and 4,4′-dihydroxyazobenzenes with secondary phosphine chalcogenides using the CCl₄/Et₃N system under mild conditions in 41–95% yield. Cis-trans photoisomerization of the phosphorylated azobenzenes was reversibly controlled by alternating UV/Vis light irradiation. The chalcogenophosphinate group imparts the properties of media-responsive molecular photoswitches to the synthesized azobenzenes.     

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.     

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.     

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     

Reactions of 2- and 4-pyrones with secondary phosphine chalcogenides: a facile synthesis of functional phosphorylated pyrones

The oxidative cross-coupling between 4-hydroxy-6-methyl-2-pyrone or 3-hydroxy-2-methyl-4-pyrone and secondary phosphine chalcogenides proceeds in CCl₄/Et₃N under mild conditions (20–52 °С, 0.75–10 h) through the hydroxyl group to give O-(6-methyl-2-oxo-2H-pyran-4-yl) diorganylphosphinochalcogenoates or O-(2-methyl-4-oxo-4H-pyran-3-yl) diorganylphosphinochalcogenoates, in high yields.     

Palladium and platinum organochalcogenolates and their transformation into metal chalcogenides

Platinum group metal chalcogenides find extensive applications in catalysis and in the electronic industry. To develop an efficient low temperature clean preparation of these materials, molecular routes have been explored. Thus the chemistry of mononuclear organochalcogenolates of the type [M(ER’)₂(PR₃)₂], binuclear benzylselenolates, [M₂Cl₂(μ-SeBz)₂(PR₃)₂], allylpalladium complexes [Pd₂(μ-ER)₂(η³-C₄H₇)₂] and palladium/platinum sulphido/selenido-bridged complexes, [M₂(μ-E)₂L₄] (M = Pd or Pt; E = S, Se or Te; L = tertiary phosphine ligand) has been investigated. All the complexes have been characterized by elemental analysis, NMR (¹H,³¹P,⁷⁷Se,¹⁹⁵Pt) spectroscopy and in some cases by X-ray diffraction. The thermal behaviour of these complexes has been studied by TGA. The pyrolysis of allylpalladium complexes in refluxing xylene yields Pd₄E as established by analysis and XRD patterns.     

Reaction of hydroxyflavones with secondary phosphine chalcogenides in the CCl4/Et3N system: synthesis of a new family of phosphorylated flavonoids

Flavonoids (3-hydroxy-, 3-hydroxy-4′-methoxy-, 3-hydroxy-7-methoxy-, and 5,7-dihydroxyflavones) react with secondary phosphine chalcogenides in the CCl₄/Et₃N redox system (50–52 °C, 3–5 h) to afford chemoselectively the corresponding chalcogenophosphinates of the hydroxyflavones in 65–82% yield.     

Fluorine-induced chemiluminescence detection of phosphine,alkyl phosphines and monophosphinate esters

Summary Phosphine, alkylated phosphines and monophosphinate esters are detected with high sensitivity in capillary gas chromatography (GC) by their chemiluminescent reactions with molecular fluorine. Detection limits are estimated to be 1.3 pg, 0.5 pg, 8 pg, and 17 pg for phosphine, trimethyl phosphine, trimethyl phosphinate ester, and triethyl phosphine, respectively. As found earlier with alkylated sulfur, selenium and tellurium compounds, the detector exhibits a linear response. For triethyl phosphine, a linear range of greater than three orders of magnitude was demonstrated. Emission spectra were obtained for the trimethyl phosphine and triethyl phosphine systems. Chemiluminescence emitters include electronically excited HCF, vibrationally excited HF, and an unknown species in the trimethyl phosphine system. Banded emission from vibrationally excited HF and a broad continuum were observed for both trimethyl phosphine and triethyl phosphine; however, HCF emission was observed only for TMP. Under the conditions employed, the principal emitter is HCF for trimethyl phosphine and HF and the unknown emitter for triethyl phosphine. This detector may have important applications in investigations of the biogeochemical cycling of phosphorus.