10311-08-7Relevant academic research and scientific papers
Aryl group - A leaving group in arylphosphine oxides
Stankevi?, Marek,Pisklak, Jolanta,W?odarczyk, Katarzyna
, p. 810 - 824 (2016/01/20)
The treatment of triphenylphosphine oxide with organometallic reagents leads to the substitution of up to three phenyl substituents with the incoming carbon nucleophile. The replacement of the phenyl/aryl group in tertiary diarylalkylphosphine oxides or even aryldialkylphosphine oxides was also observed. Naphthyl-substituted phosphine oxides undergo Michael-type addition at the naphthyl group when treated with organolithium reagent.
Direct conversion of phosphonates to phosphine oxides: An improved synthetic route to phosphines including the first synthesis of methyl JohnPhos
Kendall, Alexander J.,Salazar, Chase A.,Martino, Patrick F.,Tyler, David R.
, p. 6171 - 6178 (2015/02/19)
The synthesis of tertiary phosphine oxides from phosphonates was achieved reliably and in good to excellent yields using stoichiometric amounts of alkyl or aryl Grignard reagents and sodium trifluoromethanesulfonate (NaOTf). In the absence of the NaOTf additive, covalent coordination oligomers of magnesium and phosphorus species dominate the reaction, producing very low yields of phosphine oxide, but high conversions of the phosphonate starting material. Mechanistic studies revealed that a five-coordinate phosphorus species - not a phosphinate - is the reaction intermediate. A diverse array of phosphonates was converted to phosphine oxides using a variety of Grignard reagents for direct carbon-phosphorus functionalization. This new methodology especially simplifies the synthesis of dimethylphosphino (RPMe2)-type phosphines by using air-, water-, and silica-stable intermediates. To highlight this reaction, a new Buchwald-type ligand ([1,1′-biphenyl]-2-yldimethylphosphine, or methyl JohnPhos) and a classic bidentate phosphine, bis(diphenylphosphino)propane (dppp), were synthesized in excellent yields.
Michael-type addition of secondary phosphine oxides to (1,4-cyclohexadien- 3-yl)phosphine oxides
Stankevic, Marek,Jaklinska, Magdalena,Pietrusiewicz, K. Michal
scheme or table, p. 1991 - 2000 (2012/04/04)
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.
Room temperature, palladium-mediated P-arylation of secondary phosphine oxides
Bloomfield, Aaron J.,Herzon, Seth B.
supporting information, p. 4370 - 4373 (2012/10/29)
We show that a broad range of aryl iodides are efficiently coupled with secondary phosphine oxides using 1 mol % of a catalyst formed in situ from tris(dibenzylideneacetone)dipalladium and Xantphos (1). Scalemic (S)-methylphenylphosphine oxide [(S)-2e] is shown to undergo arylation without detectable stereoerosion. The application of this method to the synthesis of novel P-chiral phosphines and PCP ligands is demonstrated.
Sodium in liquid ammonia - A versatile tool in modifications of arylphosphine oxides
Stankevi?, Marek,W?odarczyk, Adam,Jaklińska, Magdalena,Parcheta, Renata,Pietrusiewicz, K. Micha?
experimental part, p. 8671 - 8678 (2011/12/03)
A simple and practical method for modifications of tertiary arylphosphine oxides based on their reaction with sodium in liquid ammonia is presented. Depending on the structure of the starting compounds, either dearomatisation of the phenyl substituent or cleavage of a P-aryl bond from phosphorus atom can be selectively performed and the corresponding (1,4-cyclohexadien-3-yl)phosphine oxides or secondary phosphine oxides were obtained in good to excellent yields.
N,N-Dimethyl-S-difluoromethyl-S-phenylsulfoximinium tetrafluoroborate: A versatile electrophilic difluoromethylating reagent
Prakash, G.K. Surya,Zhang, Zhe,Wang, Fang,Ni, Chuanfa,Olah, George A.
experimental part, p. 792 - 798 (2011/10/09)
Over the past decade, sulfur-based fluoromethyl containing compounds have been exhaustively investigated as versatile fluoroalkylating reagents by our research laboratory as well as many others. Lately, we have designed a novel electrophilic difluoromethylating protocol employing in situ prepared N,N-dimethyl-S-difluoromethyl-S-phenylsulfoximinium salt. The present reagent provides excellent reactivity toward a broad spectrum of nucleophilic species (N-, P-, S-, and O-nucleophiles) to yield the corresponding difluoromethylated products with high efficacy under mild conditions. Additional studies have been performed to elucidate the mechanistic fundamentals of the reactions.
Highly efficient [Ni{iPrHNC(S)NP(S)(OiPr)2-1,3-N,S′} 2]/PR3 (R3 = Me3, Me2Ph) complexes for the generation of Ni0 for catalysis
Safin, Damir A.,Babashkina, Maria G.,Bolte, Michael,Hahn, F. Ekkehardt
scheme or table, p. 4806 - 4809 (2011/06/27)
We have developed new complexes of the type [Ni{iPrHNC(S)NP(S)(OiPr) 2-1,3-N,S′}2]/PR3 (R3 = Me3, Me2Ph) for the generation of Ni0 catalysts which can be used for the catalytic addition of Ph2S2 to 1-, 2- and 3-hexynes. A detailed study of the catalytic reaction mechanism suggests two possible pathways for the in situ formation of Ni0 species, depending on the presence or absence of water.
Mechanisms of hydrogen-, oxygen-, and electron-transfer reactions of cumylperoxyl radical
Fukuzumi, Shunichi,Shimoosako, Kanji,Suenobu, Tomoyoshi,Watanabe, Yoshihito
, p. 9074 - 9082 (2007/10/03)
Rates of hydrogen-transfer reactions from a series of para-substituted N,N-dimethylanilines to cumylperoxyl radical and oxygen-transfer reactions from cumylperoxyl radical to a series of sulfides and phosphines have been determined in propionitrile (EtCN) and pentane at low temperatures by use of ESR. The observed rate constants exhibit first-order and second-order dependence with respect to concentrations of N,N-dimethylanilines. This indicates that the hydrogen- and oxygen-transfer reactions proceed via 1:1 charge-transfer (CT) complexes formed between the substrates and cumylperoxyl radical. The primary kinetic isotope effects are determined by comparing the rates of N,N-dimethylanilines and the corresponding N,N-bis(trideuteriomethyl)anilines. The isotope effect profiles are quite different from those reported for the P-450 model oxidation of the same series of substrates. Rates of electron-transfer reactions from ferrocene derivatives to cumylperoxyl radical have also been determined by use of ESR. The catalytic effects of Sc(OTf)3 (OTf = triflate) on the electron-transfer reactions are compared with those of Sc(OTf)3 on the hydrogen- and oxygen-transfer reactions. Such comparison provides strong evidence that the hydrogen- and oxygen- transfer reactions of cumylperoxyl radical proceed via a one-step hydrogen atom and oxygen atom transfer rather than via an electron transfer from substrates to cumylperoxyl radical.
Solvolysis of phosphonium compounds containing a thiophenoxy group linked to phosphorus
Aksnes, Gunnar
, p. 43 - 50 (2007/10/03)
A kinetic study of the solvolysis of six alkylphenyl thiophenoxyphosphonium chlorides in 50% water/ methanol is reported. The rates of solvolysis, where thiophenol and phosphine oxides are formed, are little influenced by the substituents linked to phosphorus. The present findings are in sharp contrast to the 104 higher rate of the alkaline decomposition of tetraphenyl as compared to trialkylphenyl phosphonium salts, where phenyl is the leaving group. Further, the rate of solvolysis of the cyclic phenyl thiophenoxyphospholanium salt, is nearly identical to the rate of the corresponding dialkylphenyl thiophenoxyphosphonium compound. Calculation of the activation parameters of the solvolysis of thiophenoxyphosphonium compounds shows that the underlying reaction forces, expressed as activation energies and entropies, are strongly influenced by the substituents. The results suggest that the thiophenoxy group is expelled from the pentacovalent, trigonal bipyramidal reaction intermediate, before pseudorotation of the substituents linked to phosphorus takes place.
sis- and trans-Dioxo complexes of chlororuthenium(VI)
Perrier,Kochi
, p. 4165 - 4173 (2008/10/08)
Dioxoruthenium(VI) complexes are prepared as the chloro derivatives O2RuCl42- and O2RuCl3- and isolated as the crystalline phosphonium and ammonium salts. Quantitative spectral studies (IR and UV-vis) establish the ready interconversion of the 6-coordinate O2RuCl42- to the 5-coordinate analogue with a dissociation constant K = 5.3 × 10-3 M for chloride loss in dichloromethane. The octahedral structure of O2RuCl42- is established by X-ray crystallography of the (Ph3P)2N+ salt to consist of trans-dioxo ligands with the asymmetric (A2u) stretching band at 830 cm-1 in the IR spectrum. [(Ph3P)2N+]2[O2RuCl 42-]: space group P1 (triclinic) with lattice constants a = 10.916 (2) A?, b = 12.378 (2) A?, c = 13.788 (2) A?, α = 105.65 (1)°, β = 93.16 (1)°, γ = 92.60 (1)°, and Z = 1. The coordinatively unsaturated trichloro derivative O2RuCl3- represents a rare example of a mononuclear dioxo complex whose solid-state structure is dependent on the counterion. Thus, the X-ray crystallography of the (Ph3P)2N+ salt establishes a trigonal-bipyramidal structure of O2RuCl3- with the cis-dioxo ligands absorbing as a single, strong IR band at 882 cm-1. [(Ph3P)2N+][O2RuCl3 -]: space group P21/n (monoclinic) with lattice constants a = 10.629 (4) A?, b = 15.636 (5) A?, c = 21.026 (7) A?, β = 99.60 (2)°, and Z = 4. The O2RuCl3- ion in the Ph4P+ salt is disordered between trigonal-bipyramidal and square-pyramidal geometries, which can be refined by using an occupancy ratio of 6:4 with R = 0.042 in the final refinement. The square-pyramidal component of O2RuCl3- is assigned with trans-dioxo ligands that account for the appearance of the unusual IR band at 891 cm-1 (together with the band at 878 cm-1) in crystalline [O2RuCl3-][Ph4P+] [tetragonal space group P4/n with lattice constants a = 12.672 (2) A?, c = 7.788 (2) A?, and Z = 2]. The (Ph3P)2N+, Ph4P+, Et4N+, and n-Bu4N+ salts of O2RuCl3- all show a single, sharp IR band at 885 cm-1 in solutions of dichloromethane or acetonitrile.
