cas 2129-89-7, METHYLDIPHENYLPHOSPHINE OXIDE

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Synthesis of stable carboxylate phosphabetaines - Potential ligands of the metal complexes
Stable mono- and dicarboxylate phosphabetaines with α-location of the phosphonium center relative to the carboxylate group on the basis of methyldiphenylphosphine, triphenylphosphine, 3-(diphenylphosphino)propionic acid, various bisdiphenylphosphines and glyoxylic acid have been synthesized.
Galkina, Irina,Romanov, Semyon,Gerasimov, Alexander,Bakhtiyarova, Yulia,Galkin, Vladimir
(2020)
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Voltage Imaging with a NIR-Absorbing Phosphine Oxide Rhodamine Voltage Reporter
The development of fluorescent dyes that emit and absorb light at wavelengths greater than 700 nm and that respond to biochemical and biophysical events in living systems remains an outstanding challenge for noninvasive optical imaging. Here, we report the design, synthesis, and application of near-infrared (NIR)-absorbing and -emitting optical voltmeter based on a sulfonated, phosphine-oxide (po) rhodamine for voltage imaging in intact retinas. We find that po-rhodamine based voltage reporters, or poRhoVRs, display NIR excitation and emission profiles at greater than 700 nm, show a range of voltage sensitivities (13 to 43% ΔF/F per 100 mV in HEK cells), and can be combined with existing optical sensors, like Ca2+-sensitive fluorescent proteins (GCaMP), and actuators, like light-activated opsins ChannelRhodopsin-2 (ChR2). Simultaneous voltage and Ca2+ imaging reveals differences in activity dynamics in rat hippocampal neurons, and pairing poRhoVR with blue-light based ChR2 affords all-optical electrophysiology. In ex vivo retinas isolated from a mouse model of retinal degeneration, poRhoVR, together with GCaMP-based Ca2+ imaging and traditional multielectrode array (MEA) recording, can provide a comprehensive physiological activity profile of neuronal activity, revealing differences in voltage and Ca2+ dynamics within hyperactive networks of the mouse retina. Taken together, these experiments establish that poRhoVR will open new horizons in optical interrogation of cellular and neuronal physiology in intact systems.
Gonzalez, Monica A.,Walker, Alison S.,Cao, Kevin J.,Lazzari-Dean, Julia R.,Settineri, Nicholas S.,Kong, Eui Ju,Kramer, Richard H.,Miller, Evan W.
p. 2304 - 2314
(2021)
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Acetylacetonate and Acetate Complexes of Nickel(II) Catalyse the Air Oxidation of Phosphines
The polymeric complex trans-[Ni(acac)2(μ2-dppe)]n·2MeCN {1a, dppe = 1,2-ethylenebis(diphenylphosphine)} is sometimes transiently deposited from the reaction of [Ni(acac)2] with dppe in MeCN prior to its facile onwards air oxidation to final crystallization of a doubly-oxygenated relative, cis-[Ni(acac)2(μ2-dppeO2)]n {2, dppeO2 = 1,2-ethylenebis(diphenylphosphineoxide)}. A similar unsolvated phase of the initial polymer, trans-[Ni(acac)2(μ2-dppe)]n (1b), can be isolated from toluene. The oxidation of dppe by O2 is catalytic and dppeO2 was isolated in close to stoichiometric yields from solutions containing 5 % Ni(acac)2 relative to dppe. The reaction rate slows after a few turnovers due to inhibition by the product. The relative yields of dppeO2 are higher than those from catalytic air oxidation of methyldiphenylphosphine and triphenylphosphine and we speculate that a pathway for this reaction involves a dimetallic cooperativity enabled specifically by dppe.
Hansen, Line Sofie,Jakobsen, Vibe Boel,McKee, Vickie,McKenzie, Christine J.
p. 4163 - 4169
(2020)
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Anionic Phosphorus as a Nucleophile. An Anion Chain Arbuzov Mechanism
The reaction of the anion of dineopentyl phosphonate with alkyl iodides is kinetically second order and yields the P-alkylated dineopentyl alkylphosphonate.This supports, as previously suggested, a simple SN2 mechanism for the reaction.Rate constants in sulfolane are reported.Trimethyl phosphate and phosphonate esters also alkylate this nucleophile. hen dimethyl phosphonate dissolved in tetrahydrofuran or in benzene is treated with solid sodium hydride at room temperature, the initially formed anion is virtually quantitatively alkylated by remaining neutral ester before it can react with sodium hydride, yielding monomethyl phosphonate anion and dimethyl methylphosphonate.This major side reaction is less important with diethyl phosphonate and is not detected with the neopentyl ester.It does not occur with butyllithium as the base or with sodium hydride at -78 deg C in either THF or benzene as the solvent.This fast reaction appears to be a surface reaction.The anion of diphenylphosphinite is similarly alkylated my methyl diphenylphosphinite, yielding methyldiphenylphosphine oxide and regenerating the anion, thus constituting a new anionic chain mechanism for the Arbuzov reaction.
Spears, L. Gene,Liao, Andrew,Minsek, David,Lewis, Edward S.
p. 61 - 64
(1987)
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Alkoxyphosphonium ions. 5. Kinetics of the Michaelis-Arbuzov intermediate
Rates of formation and destruction of the alkoxyphosphonium ion, the intermediate in the Michaelis-Arbuzov reactions of some methyl esters of trivalent phosphorus acids with methyl iodide, are followed by a conductivity method in the solvent propylene carbonate.Specific conductances of the unstable intermediates are well estimated through stable model salts.Rate constants for both the alkylation of the reagent and the dealkylation of the intermediate are obtained.The conductivity time curves are simulated by adjusting rate constants for two sequential second order reactions, assuming no ion pairing at the concentrations used.In these measurements of the intermediate only, there is no rate-determining step; for the overall rection the first step is in most cases rate-determining.
Lewis, Edward S.,McCortney, Briget A.
p. 1156 - 1160
(1986)
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The Trityl-Cation Mediated Phosphine Oxides Reduction
Reduction of phosphine oxides into the corresponding phosphines using PhSiH3 as a reducing agent and Ph3C+[B(C6F5)4]? as an initiator is described. The process is highly efficient, reducing a broad range of secondary and tertiary alkyl and arylphosphines, bearing various functional groups in generally good yields. The reaction is believed to proceed through the generation of a silyl cation, which reaction with the phosphine oxide provides a phosphonium salt, further reduced by the silane to afford the desired phosphine along with siloxanes. (Figure presented.).
Landais, Yannick,Laye, Claire,Lusseau, Jonathan,Robert, Frédéric
supporting information
p. 3035 - 3043
(2021/05/10)

Evaluation of bifunctional chiral phosphine oxide catalysts for the asymmetric hydrosilylation of ketimines
A series of bifunctional phosphine oxides have been prepared and evaluated as catalysts for the trichlorosilane mediated asymmetric hydrosilylation of ketimines. bis-Phosphine oxides, hydroxy-phosphine oxides, and biaryl phosphine oxides all demonstrated good catalytic activity, but poor to moderate enantioselectivity. A bis-P-chiral phosphine oxide displayed the highest enantioselectivity of 60%.
Warner, Christopher J.A.,Berry, Sian S.,Jones, Simon
(2019/11/11)

Hydrotrifluoromethylthiolation of Unactivated Alkenes and Alkynes with Trifluoromethanesulfonic Anhydride through Deoxygenative Reduction and Photoredox Radical Processes
An ongoing challenge in trifluoromethylthiolation reactions is the use of less expensive and easily available trifluoromethylthio sources. Herein, we disclose an unprecedented usage of trifluoromethanesulfonic anhydride (Tf2O) as a radical trifluoromethylthiolating reagent. Hydrotrifluoromethylthiolation of unactivated alkenes and alkynes with Tf2O in the presence of PMePh2 and H2O under visible-light photoredox catalysis gave the addition products. The trifluoromethylthio radical (.SCF3) was first formed from Tf2O through a photoredox radical processes and deoxygenative reduction of PMePh2, and H2O serves as the H-atom donor for the hydrotrifluoromethylthiolation reaction. This reaction provides a new strategy for radical trifluoromethylthiolation.
Ouyang, Yao,Xu, Xiu-Hua,Qing, Feng-Ling
supporting information
p. 18508 - 18512
(2019/11/14)

Water determines the products: An unexpected Br?nsted acid-catalyzed PO-R cleavage of P(iii) esters selectively producing P(O)-H and P(O)-R compounds
Water is found able to determine the selectivity of Br?nsted acid-catalyzed C-O cleavage reactions of trialkyl phosphites: with water, the reaction quickly takes place at room temperature to afford quantitative yields of H-phosphonates; without water, the reaction selectively affords alkylphosphonates in high yields, providing a novel halide-free alternative to the famous Michaelis-Arbuzov reaction. This method is general as it can be readily extended to phosphonites and phosphinites and a large scale reaction with much lower loading of the catalyst, enabling a simple, efficient, and practical preparation of the corresponding organophosphorus compounds. Experimental findings in control reactions and substrate extension as well as preliminary theoretical calculation of the possible transition states all suggest that the monomolecular mechanism is preferred.
Li, Chunya,Wang, Qi,Zhang, Jian-Qiu,Ye, Jingjing,Xie, Ju,Xu, Qing,Han, Li-Biao
supporting information
p. 2916 - 2922
(2019/06/18)

Phosphine Oxidation with Water and Ferrocenium(III) Cation Induced by Visible-Light Irradiation
Stoichiometric oxidation of phosphines with water and ferrocenium(III) cation as the oxygen atom source and the oxidizing reagent, respectively, was achieved in acetonitrile under visible-light irradiation by using 2,6-lutidine as the proton acceptor. The reaction required light irradiation, under which fluorescence was observed for the acetonitrile solution of the ferrocenium(III) cation.
Tanabe, Yoshiaki,Nakajima, Kazunari,Nishibayashi, Yoshiaki
supporting information
p. 18618 - 18622
(2018/11/30)

Air- and water-stable Lewis acids: Synthesis and reactivity of P-trifluoromethyl electrophilic phosphonium cations
A new class of electrophilic phosphonium cations (EPCs) containing a -CF3 group attached to the phosphorus(v) center is readily accessible in high yields, via a scalable process. These species are stable to air, water, alcohol and strong Br?nsted acid, even at raised temperatures. Thus, P-CF3 EPCs are more robust than previously reported EPCs containing P-X moieties (X = F, Cl, OR), and despite their reduced Lewis acidity they function as Lewis acid catalysts without requiring anhydrous reaction conditions.
Fasano,LaFortune,Bayne,Ingleson,Stephan
supporting information
p. 662 - 665
(2018/02/06)

Ir(III)-catalyzed direct C-H functionalization of arylphosphine oxides: A strategy for MOP-type ligands synthesis
Diazo compounds as coupling partners are efficiently applied to Ir(III)-catalyzed direct C-H functionalization of arylphos-phine oxides. Involving C-H activation, carbene insertion, and tautomerism, this reaction proceeds under mild conditions, thus proving an approach to the synthesis of MOP-type ligand precursor in a single step. The utility of this transformation has been further demonstrated in ligand synthesis as well as in the construction of phosphole framework.
Liu, Zhong,Wu, Ji-Qiang,Yang, Shang-Dong
supporting information
p. 5434 - 5437
(2017/11/06)

Differentially Substituted Phosphines via Decarbonylation of Acylphosphines
A new route to phosphines was developed by a method that features a "pre-join and transform" process that proceeds via acylphosphine intermediates that may be readily prepared from carboxylic acids and disubstituted phosphines. The efficient decarbonylations of these acylphosphines using a nickel catalyst delivered the corresponding phosphines. This method shows that the carboxyl group can play a role similar to halides or triflates for introducing a substituted phosphorus atom on an aromatic ring.
Yu, Rongrong,Chen, Xingyu,Martin, Stephen F.,Wang, Zhiqian
p. 1808 - 1811
(2017/04/11)

The Mechanism of Phosphonium Ylide Alcoholysis and Hydrolysis: Concerted Addition of the O?H Bond Across the P=C Bond
The previous work on the hydrolysis and alcoholysis reactions of phosphonium ylides is summarized and reviewed in the context of their currently accepted mechanisms. Several experimental facts relating to ylide hydrolysis and to salt and ylide alcoholysis are shown to conflict with those mechanisms. In particular, we demonstrate that the pKavalues of water and alcohols are too high in organic media to bring about protonation of ylide. Therefore, we propose concerted addition of the water or alcohol O?H bond across the ylide P=C bond. In support of this, we provide NMR spectroscopic evidence for equilibrium between ylide and aclohol that does not require the involvement of phosphonium hydroxide. We report the first P-alkoxyphosphorane to be characterised by NMR spectroscopy that does not undergo exchange on an NMR timescale. Two-dimensional NMR spectroscopic techniques have been applied to the characterisation to P-alkoxyphosphoranes for the first time.
Byrne, Peter A.,Gilheany, Declan G.
supporting information
p. 9140 - 9154
(2016/07/14)

Aryl group - A leaving group in arylphosphine oxides
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.
Stankevi?, Marek,Pisklak, Jolanta,W?odarczyk, Katarzyna
p. 810 - 824
(2016/01/20)

PHOSPHINE COMPOUND HAVING PERFLUORO GROUP, AND COMPLEX BETWEEN METAL AND PHOSPHINE HAVING PERFLUORO GROUP
PROBLEM TO BE SOLVED: To provide a perfluoroalkylphosphine compound, and a complex between a metal and the perfluoroalkylphosphine. SOLUTION: A perfluoroalkylphosphine compound is a phosphine compound represented by the general formula Rf-PR1R2. In the formula, R1 and R2 are each independently a substituted or unsubstituted hydrocarbon group; Rf is a perfluorinated hydrocarbon group. Also provided is a complex between the perfluoroalkylphosphine and a phosphine coordination metal. SELECTED DRAWING: None COPYRIGHT: (C)2016,JPOandINPIT
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(2018/10/16)

Synthesis and properties of novel polyimide fibers containing phosphorus groups in the main chain
A series of polyamic acid copolymers (co-PAAs) containing phosphorous groups in the main chain were synthesized using different ratios of two diamines, i.e., bis(3-aminophenyl)methyl phosphine oxide (DAMPO) and 4,4′-oxydianiline (ODA), with 3,3′,4,4′-biphenyltetracarboxylic dianhydride (s-BPDA) by polycondensation in N,N′-dimethyacetamide (DMAc). The co-PAA solutions were spun into fibers by a dry-jet wet spinning process, and then polyimide copolymer (co-PI) fibers were obtained by thermal imidization. ATR-FTIR spectra and elemental analysis confirmed the chemical structure of PAA and PI fibers. The as-prepared PI fibers have smooth and dense surface as well as uniform diameter. Compared with the blank PI-0, the Tg values of co-PI fibers increased considerably with the increase in DAMPO content. TGA results indicated that the co-PI fibers possessed good thermal stability up to 510 °C and a residual char yield of up to 61% at 850 °C. All co-PI fibers exhibited excellent elongation, and their tensile strength and modulus can reach 0.9 GPa and 14.97 GPa when the molar ratio of DAMPO/ODA was 6/4 and the draw ratio was 3.0. The relationship between microstructure and mechanical property is also discussed.
Zhao, Yong,Feng, Tao,Li, Guomin,Liu, Fangfang,Dai, Xuemin,Dong, Zhixin,Qiu, Xuepeng
p. 42482 - 42494
(2016/05/19)

Synthesis of phosphorus- and sulfur-stabilized carbone (Me)Ph2P→C←SPh2(= NMe)
Iminosulfane(phosphane)carbon(0) (iSPC) [(Me)Ph2P→C←SPh2(= NMe): 1] is generated by the deprotonation of corresponding cationic salt 1·H, which is obtained from the reaction of iminosulfonium methylide with Ph2PCl and subsequent P-methylation. Density functional theory calculations reveal that the electronic structure of 1 has two lone pairs of electrons at the carbon center. First and second proton affinity values are theoretically calculated to be 287.2 and 187.0 kcal mol-1, respectively. The highest occupied molecular orbital (HOMO) energy level of 1 is higher energy than that of bis(iminosulfane)carbon(0) (BiSC: [(MeN =)Ph2S→C←SPh2(= NMe)]). The reactivities of these lone pairs of electrons are demonstrated by the C-diaurated complex.
Morosaki, Tomohito,Fujii, Takayoshi
p. 159 - 162
(2016/02/18)

An ultra-stable oxoiron(iv) complex and its blue conjugate base
Treatment of [FeII(L)](OTf)2 (4), (where L = 1,4,8-Me3cyclam-11-CH2C(O)NMe2) with iodosylbenzene yielded the corresponding S = 1 oxoiron(iv) complex [Fe IV(O)(L)](OTf)2 (5) in nearly quantitative yield. The remarkably high stability of 5 (t1/2 ≈ 5 days at 25°C) facilitated its characterization by X-ray crystallography and a raft of spectroscopic techniques. Treatment of 5 with strong base was found to generate a distinct, significantly less stable S = 1 oxoiron(iv) complex, 6 (t 1/2 ～ 1.5 h at 0°C), which could be converted back to 5 by addition of a strong acid; these observations indicate that 5 and 6 represent a conjugate acid-base pair. That 6 can be formulated as [FeIV(O)(L-H)] (OTf) was further supported by ESI mass spectrometry, spectroscopic and electrochemical studies, and DFT calculations. The close structural similarity of 5 and 6 provided a unique opportunity to probe the influence of the donor trans to the FeIVO unit upon its reactivity in H-atom transfer (HAT) and O-atom transfer (OAT), and 5 was found to display greater reactivity than 6 in both OAT and HAT. While the greater OAT reactivity of 5 is expected on the basis of its higher redox potential, its higher HAT reactivity does not follow the anti-electrophilic trend reported for a series of [FeIV(O)(TMC) (X)] complexes (TMC = tetramethylcyclam) and thus appears to be inconsistent with the two-state reactivity rationale that is the prevailing explanation for the relative facility of oxoiron(iv) complexes to undergo HAT. The Royal Society of Chemistry 2014.
England, Jason,Bigelow, Jennifer O.,Van Heuvelen, Katherine M.,Farquhar, Erik R.,Martinho, Marlene,Meier, Katlyn K.,Frisch, Jonathan R.,Muenck, Eckard,Que, Lawrence
p. 1204 - 1215
(2014/03/21)

Iridium(III)-Catalyzed C H Amidation of Arylphosphoryls Leading to a P-Stereogenic Center
Direct C H amidation of arylphosphoryl compounds has been developed by using an IrIIIcatalyst system under mild conditions. A wide range of substrates could be employed with high functional-group tolerance. This procedure was successfully applied for the first time to the asymmetric reaction giving rise to a P-chirogenic center with a high diastereomeric ratio of up to 19:1 (90 % de).
Gwon, Donghyeon,Lee, Donggun,Kim, Jiyu,Park, Sehoon,Chang, Sukbok
supporting information
p. 12421 - 12425
(2016/08/25)

Direct conversion of phosphonates to phosphine oxides: An improved synthetic route to phosphines including the first synthesis of methyl JohnPhos
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.
Kendall, Alexander J.,Salazar, Chase A.,Martino, Patrick F.,Tyler, David R.
supporting information
p. 6171 - 6178
(2015/02/19)

Ruthenium-catalyzed ortho -alkenylation of phenylphosphine oxides through regio- and stereoselective alkyne insertion into C-H bonds
Direct ortho-substitution took place efficiently upon treatment of tri-, di-, and monoarylphosphine oxides with internal alkynes in the presence of a ruthenium catalyst to produce (o-alkenylphenyl)phosphine oxides regio- and stereoselectively. Chemoselective reduction of a product gave the corresponding (o-alkenylphenyl)phosphine, which may be useful as a ligand for transition metals.
Itoh, Masaki,Hashimoto, Yuto,Hirano, Koji,Satoh, Tetsuya,Miura, Masahiro
p. 8098 - 8104
(2013/09/12)

Room temperature, palladium-mediated P-arylation of secondary phosphine oxides
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.
Bloomfield, Aaron J.,Herzon, Seth B.
supporting information
p. 4370 - 4373
(2012/10/29)

Catalytic phosphorus(V)-mediated nucleophilic substitution reactions: Development of a catalytic appel reaction
Catalytic phosphorus(V)-mediated chlorination and bromination reactions of alcohols have been developed. The new reactions constitute a catalytic version of the classical Appel halogenation reaction. In these new reactions oxalyl chloride is used as a consumable stoichiometric reagent to generate the halophosphonium salts responsible for halogenation from catalytic phosphine oxides. Thus, phosphine oxides have been transformed from stoichiometric waste products into catalysts and a new concept for catalytic phosphorus-based activation and nucleophilic substitution of alcohols has been validated. The present study has focused on a full exploration of the scope and limitations of phosphine oxide catalyzed chlorination reactions as well as the development of the analogous bromination reactions. Further mechanistic studies, including density functional theory calculations on proposed intermediates of the catalytic cycle, are consistent with a catalytic cycle involving halo- and alkoxyphosphonium salts as intermediates.
Denton, Ross M.,An, Jie,Adeniran, Beatrice,Blake, Alexander J.,Lewis, William,Poulton, Andrew M.
experimental part
p. 6749 - 6767
(2011/10/02)

Correlation of the rates of solvolysis of chlorodiphenylphosphine using the extended grunwald-winstein equation
Specific rates of solvolysis involving displacement of chloride from the trivalent phosphorus of chlorodiphenylphosphine (Ph2PCl, 1) are reported for ethanol, methanol, and aqueous binary mixtures incorporating ethanol, methanol, acetone, 2,2,2-trifluoroethanol (TFE), and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). The 25 solvents give an extended Grunwald-Winstein correlation with an l value of 1.25 0.09, m value of 0.46 0.06, and correlation coefficient (R) of 0.954. The reactions in aqueous acetone were unusually fast, and these data points lie above the plot. Specific rate values are also reported for TFE-ethanol mixtures. For five representative solvents, values were obtained at three additional temperatures and activation parameters are presented. Rather low enthalpies of activation (8.4 to 11.8 kcal mol-1) are accompanied by very negative entropies of activation (-33 to -46 cal mol-1K-1). The kinetic features observed are consistent with an SN2 reaction incorporating appreciable bond formation and bond breaking at the transition state, and they are very similar to those previously observed for diphenylphosphinyl chloride (Ph2POCl).
Koh, Han Joong,Kevill, Dennis N.
experimental part
p. 865 - 874
(2010/07/15)

Reaction of N-vinylic phosphazenes with α,β-unsaturated aldehydes. Azatriene-mediated synthesis of dihydropyridines and pyridines derived from β-amino acids
Aza-Wittig reaction of N-vinylic phosphazenes (1,2 addition), derived from diphenylmethylphosphine or derived from trimethylphosphine with α,β-unsaturated aldehydes, leads to the formation of 3-azatrienes through a [2 + 2]-cycloaddition-cycloreversion sequence. The presence of an alkyl substituent in position 3 of N-vinylic phosphazenes increases the steric interactions, and [4 + 2] periselectivity (1,4 addition) is observed. Reaction of azatrienes with α,β-unsaturated aldehydes yields pyridines.
Palacios, Francisco,Herran, Esther,Alonso, Concepcion,Rubiales, Gloria,Lecea, Begona,Ayerbe, Mirari,Cossio, Fernando P.
p. 6020 - 6030
(2007/10/03)

Mechanism of decomposition of quasiphosphonium intermediates: Borderline SN1 character of alkyl-oxygen fission in sec-alkyloxyphosphonium salts
Short-lived alkoxyphosphonium intermediates have been detected in the interactions of alkyl diphenylphosphinites ROPPh2 (R = Et, Pr i, Bu8, and 3-pentyl) with iodomethane at room temperature. Phosphorus chemical shifts for the sec-alkoxy(methyl) diphenylphosphonium iodides (δp 68.6-68.7 ppm) are at slightly higher field than for ethoxy(methyl)diphenylphosphonium iodide (δp 72.4 ppm), in accord with higher electron density at phosphorus in the secondary alkyl sytems. Relative rates of decomposition in CDCl3 (Me > Et > Pri ? neopentyl) are in accord with SN2-type cleavage of the R-O bond but within the secondary alkyl series the relative rates (Pri 8 N1 mechanism is proposed.
Hudson,Qureshi
p. 473 - 480
(2007/10/03)

Mechanisms of hydrogen-, oxygen-, and electron-transfer reactions of cumylperoxyl radical
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.
Fukuzumi, Shunichi,Shimoosako, Kanji,Suenobu, Tomoyoshi,Watanabe, Yoshihito
p. 9074 - 9082
(2007/10/03)

Lewis acid catalyzed room-temperature Michaelis-Arbuzov rearrangement
The taming of the shrew! For the first time, a broadly applicable efficient room-temperature Arbuzov rearrangement is described. This reaction is accomplished through an atom-economical Lewis acid catalyzed process (see scheme, TMSOTf=trimethylsilyl trifluoromethane-sulfonate). The method has been generalized to primary and activated secondary phosphites, phosphinites, and phosphonites.
Renard, Pierre-Yves,Vayron, Philippe,Leclerc, Eric,Valleix, Alain,Mioskowski, Charles
p. 2389 - 2392
(2007/10/03)

Trimethylsilyl halide-promoted Michaelis-Arbuzov rearrangement
(Matrix presented) We describe a new, straightforward, and easy-to-handle method for achieving an unprecedented trimethylsilyl halide-catalyzed Michaelis-Arbuzov-like rearrangement. This rearrangement occurs at temperatures from room temperature to 80°C and does not require addition of any alkyl halide. The scope and limitations of this new reaction are explored, as well as its mechanism.
Renard, Pierre-Yves,Vayron, Philippe,Mioskowski, Charles
p. 1661 - 1664
(2007/10/03)

Direct use of chiral or achiral organophosphorus boranes as pro-ligands for transition metal catalyzed reactions
Chiral or achiral organophosphorus borane complexes were used without isolation of the free tricoordinate P(III) ligand; thus, the borane adducts could be used either directly with metal salts to perform the catalysis, or they could be decomplexed by DABCO, or cyclooctadiene, and used in situ to generate the catalytic species. Chiral copper, palladium and rhodium complexes prepared using this method, were tested in asymmetric organometallic catalyzed 1,4-addition to 2-cyclohexenone, allylation of Schiff base and hydrogenation of α-acetamidocinnamic acid derivatives, respectively.
Darcel, Christophe,Kaloun, El Bachir,Merdès, Rachid,Moulin, Dominique,Riegel, Nadège,Thorimbert, Serge,Genêt, Jean Pierre,Jugé, Sylvain
p. 333 - 343
(2007/10/03)

Labile P-C bonds: P-(phosphinoyl)methyl-λ5-phosphazenes and related compounds
N-Aryl-P,P-diphenyl-P-(diphenylphosphinoyl)methyl-λ5-pho sphazenes undergo smooth acid-catalysed hydrolysis with concomitant P-C bond fission yielding N-aryl-P,P-diphenylphosphinamides and diphenylmethylphosphane oxide. A tentative mechanistic explanation is given.
Alajarín, Mateo,López-Leonardo, Carmen,Llamas-Lorente, Pilar
p. 1041 - 1043
(2007/10/03)

Oxidation of phosphines by supercritical nitrous oxide
(Matrix presented) Despite its reputation for lack of reactivity at moderate temperatures, nitrous oxide is capable of oxidizing at least one class of organic compounds, the phosphines, at temperatures at or below 100°C. The use of supercritical N2O as both the solvent and the reactant simplifies the isolation of the products and allows one to avoid the use of flammable liquid solvents.
Poh, Scott,Hernandez, Raquel,Inagaki, Mayuko,Jessop, Philip G.
p. 583 - 585
(2008/02/11)

Reaction of N-vinylic phosphazenes derived from β-amino acids with aldehydes. Azadiene-mediated synthesis of dihydropyridines, pyridines, and polycyclic nitrogen derivatives
Enamino phosphonium salts 2 are obtained by 1,2-addition of hydrogen chloride to N-vinylic phosphazenes 1 derived from triphenylphosphine. Aza- Wittig reaction of phosphazenes 1 derived from triphenylphosphine and 6 derived from diphenylmethylphosphine with aldehydes 3 leads to the formation of 2-azadienes 7. Reaction of azadienes 7 with enamines affords dihydropyridines 9 and 11, pyridines 12, and bicyclic nitrogen heterocycles 15-18 in a regioselective fashion, while heterodiene 20 reacts in the same way with pyrrolidinocyclohexanone giving 1-azaphenanthrene compound 21. Reaction of enamino phosphonium salts 2 with aldehydes 3 gives symmetrical dihydropyridines 5.
Palacios, Francisco,Herran, Esther,Rubiales, Gloria
p. 6239 - 6246
(2007/10/03)

Synthesis of phosphane oxides and phosphonates by cerium-mediated addition of organolithium compounds to chloro-phosphorus compounds
The addition of organocerium reagents 2a-g to phosphinoyl chloride 1a or chlorophosphates 1b leads to the synthesis of phosphane oxides 3aa-ag and phosphonates 3bb, be in good to high yield. The reaction can be extended to cerium enolates 4 (of ketones) and 6 (of nitriles) except when a benzyl group bound to the carbonyl moiety should be metallated. The latter reaction is the first reported synthesis of β-oxophosphane oxides by a simple reaction between enolates and a phosphorus(V) halide.
Dalpozzo, Renato,De Nino, Antonio,Miele, Daniela,Tagarelli, Antonio,Bartoli, Giuseppe
p. 2299 - 2301
(2007/10/03)

A novel carbon leaving group in the reaction of organometallic compounds with phosphine oxides
The reaction of diphenyl(methoxymethyl)phosphine oxide 1 with organometallic reagents was found to lead to substitution of the methoxymethyl group. The P-phenyl substituent showed a lower propensity to undergo a displacement.
Cardellicchio, Cosimo,Fracchiolla, Giuseppe,Naso, Francesco,Tortorella, Paolo,Holody, Wieslawa,Michal Pietrusiewicz
p. 5773 - 5776
(2007/10/03)

Quaternary ammonium salts as alkylating agents in the synthesis of tertiary phosphine oxides
A procedure was developed for the synthesis of tertiary phosphine oxides by alkylation of secondary phosphine oxides with quaternary ammonium salts.
Zalinyan, S. A.,Khachatryan, R. A.,Indzhikyan, M. H.
p. 388 - 390
(2007/10/03)

The synthesis of alkenes via epi-phosphonium species: 2. A phosphorus Ramberg-Backlund reaction
Stilbene may be synthesised with Z-selectivity from (α- bromobenzyl)benzyldiphenylphosphonium bromide by the action of amine bases. A series of stilbenes was synthesised by the action of N-bromosuccinimide and 2,2,6,6-tetramethylpiperidine directly upon dibenzyldiphenylphosphonium salts. The reaction, essentially a phosphonium analogue of the Ramberg- Backlund displays cis selectivity. The dibenzyldiphenylphosphonium salts were prepared by the one pot polymethylhydrosiloxane/titanium(IV) isopropoxide mediated reduction/alkylation of benzyldiphenylphosphine oxides.
Lawrence, Nicholas J.,Muhammad, Faiz
p. 15361 - 15370
(2007/10/03)

Pyrazine-based polymeric complex of oxodiperoxochromium (VI) compound as a new stable, mild, efficient and versatile oxidant in organic synthesis
The title compound was prepared and characterized by conventional methods. Its uses as stoichiometric oxidizing agent for a variety of organic compounds are described. With this reagent alcohols are converted to the corresponding carbonyl compounds. With 1,2-dioles C-C bond cleavage occurs. Decarboxylation of α-hydroxy acids proceeds quantitatively. Also thiols are converted to disulfides, hydroxy phenols to quinones, benzylamines to carbonyl compounds, tertiaryamines to the N-oxides, phosphines to phosphine oxides, sulfides to sulfoxides, and anthracene and phenanthrene to quinones. Deprotection of oximes and oxidative deprotection of silyl ethers proceed easily.
Tamami, Bahman,Yeganeh, Hamid
p. 7889 - 7896
(2007/10/03)

Synthesis of pentasubstituted pyridines. Cycloadditions of N-vinylic heterocumulenes with 1-(N,N-diethylamine)prop-1-yne
The reactions of N-vinyl carbodiimides 4 and 5, and N-vinyl ketenimine 6 with ynamine 7 in THF, chloroform, toluene, and xylenes at, respectively, 0 °C, 25 °C, 100 °C, and 140 °C is shown. Pentasubstituted pyridines 8, 9, 11, and 12 are obtained in very high yields through thermally controlled [2+2] or [4+2] competitive processes. Additionally, when the temperature is raised the N-vinyl heterocumulenes 5 and 6 undergo an electrocyclic ring closure of six electrons driving to isoquinolines 10 and 13, respectively.
Barluenga, Jose,Ferrero, Miguel,Palacios, Francisco
p. 4521 - 4530
(2007/10/03)

Solvolysis of phosphonium compounds containing a thiophenoxy group linked to phosphorus
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.
Aksnes, Gunnar
p. 43 - 50
(2007/10/03)

Oxidations of ER3 (E = P, As, or Sb) by hydrogen peroxide. Methylrhenium trioxide as catalyst
Catalytic and noncatalytic conversions of tertiary phosphines to their oxides by hydrogen peroxide have been investigated. The catalyst is methylrhenium trioxide, CH3ReO3. The kinetics were investigated in acetonitrile-water (1:1 by volume) at 25°C. Stepwise interactions between CH3ReO3 and H2O2 form CH3Re(η2-O2)(O)2(OI2). A, and CH3Re(η2-O2)2(O)(OH2), B. In CH3CN-H2O (1:1 v/v) the equilibrium constants are K1 = 13 ± 2 L mol-1 and K2 = 136 ± 28 L mol-1 at pH 1.0 and 25°C. The forward and reverse rate constants for the formation of A in this medium are k1 = 32.5 ± 0.3 L mol-1 s-1 and k-1 - 3.0 ± 0.2 s-1. Systematic changes in the substituents on phosphorus were made to vary the nucleophilicity of the phosphine and its cone angles; the kinetic effects are discernible, although they lie in a narrow range. Triphenylarsine and triphenylstibine were also studied, and their rates are within a factor of 2 of that for PPh3. The rhenium peroxides A and B show a small difference in reactivity. The bimolecular reactions between A and most of the phosphines have rate constants of the order 105 L mol-1 s-1. The kinetic data support a mechanism that allows nucleophilic attack of the substrate at the rhenium peroxides.
Abu-Omar,Espenson
p. 272 - 280
(2007/10/02)

A NEW, UNEXPECTED REACTION OF PHOSPHONOCHLORIDOTHIONATES WITH ALKYL ARYL ETHERS AND ALKYL CHLORIDES UNDER THE FRIEDEL-CRAFTS REACTION CONDITIONS
Phosphonochloridothionates have been found to react in the presence of Lewis acids with alkyl aryl ethers to give S-alkyl O-aryl phosphonothiolates and with alkyl halides to form products of the S-alkylation. Key words: Alkyl arel ethers; phosphonochloridothionates; alkylation; S-alkyl O-aryl phosphonothiolates; S-alkyl alkyl(aryl) dichlorophosphonium salts; conductivity.
Omelanczuk, Jan
p. 93 - 102
(2007/10/02)

Stereocontrolled Synthesis of the Sex Pheromone of Nezara viridula (L.)
The main component of the green stink bug Nezara viridula (L.) sex pheromone, the (Z)-(1S,2R,4S)-(-)-epoxybisabolene (1), has been synthesized by a convergent stereocontrolled sequence, using (S)-(-)-perillyl alcohol (2) as starting material. - Key Words: Pheromones / Green stink bug / Nezara viridula (L.) / Bisabolene, (Z)-(-)-epoxy / Epoxides
Baptistella, Lucia Helena Brito,Aleixo, Adriana Mendes
p. 785 - 790
(2007/10/02)

PHASE-TRANSFER CATALYTIC ALKYLATION OF HYDROTHIOPHOSPHORYL COMPOUNDS. IV. REACTIONS WITH PRIMARY ALKYL HALIDES
A convenient general method for the synthesis of compounds containing a thiophosphoryl group was elaborated on the basis of the Michaelis-Becker reaction with the use of the method of phase-transfer catalysis. The influence of the nature of the hydrothiophosphoryl compounds, of the alkylating agents, and of the reaction conditions on the yields of alkylated products was investigated in detail.
Aladzheva, I. M.,Odinets, I. L.,Petrovskii, P. V.,Mastryukova, T. A.,Kabachnik, M. I.
p. 431 - 437
(2007/10/02)

KINETICS OF THE PTC-WITTIG REACTIONS OF 2-BUTENYLMETHYLDIPHENYLPHOSPHONIUM YLIDS
The kinetics and linear free energy relationship of PTC-Wittig reaction between substituted aromatic aldehydes and title compound are discussed.
Huang, Wenfang,Ding, Mingwu,Xiao, Wenjing,Wu, Tianjie
p. 196
(2007/10/02)

Reactions of (1-Chlorovinyl)diphenylphosphine Oxide with Organometallic Reagents
Direct substitution of 1-chlorovinyl group by an aryl or an alkyl group in the reactions of (1-chlorovinyl)diphenylphosphine oxide with aryl and alkyl Grignard reagents was observed, whereas in its reactions with the corresponding cuprates addition across the double bond constituted the dominant reaction pathway.
Cardellicchio, Cosimo,Fiandanese, Vito,Naso, Francesco,Pietrusiewicz, K. Michal,Wisniewski, Witold
p. 3135 - 3138
(2007/10/02)

Stereochemistry of direct olefin formation from carbonyl compounds and lithiated heterocyclic sulfones
The conditions for the title reaction were studied for the 2-benzothiazole and 2-pyridine series and for some examples in the 2-pyrimidine series.The olefin preparations were generally observed to be more efficient for 2-BT-sulfone systems.From the data of the hundred cases studied, it can be concluded that (E)-olefins are obtained: (i) from saturated BT-sulfones and aromatic aldehydes; and (ii) from benzylic BT-sulfones and branched saturated aldehydes (isobutyraldehyde, pivalaldehyde) or α,β-ethylenic or aromatic aldehydes. (Z)-olefins arise: (i) fom propargylic BT-sulfones and saturated or aromatic aldehydes; and (ii) from allylic or benzylic Pyr-sulfones and saturated aldehydes.Possible mechanisms for this new olefination procedure were examined. - heteroaromatic sulfones, organolithium derivatives, intramolecular ipso reactions, stereochemistry, elimination, olefination.
Baudin, J. B.,Hareau, G.,Julia, S. A.,Lorne, R.,Ruel, O.
p. 856 - 878
(2007/10/02)

ZUR SYNTHESE UND REAKTIVITAET METHYLENVERBRUECKTER DIPHOSPHORYLVERBINDUNGEN
An improved high-yield Arbusov-type synthesis for diphosphorylmethanes with different substituents on both phosphorus atoms (4, 5, 7) by the reaction of isopropyl diphenylphosphinite or diisopropyl phenylphosphonite with diisopropyl bromomethylphosphonate (1) or isopropyl phenyl-bromomethylphosphinate (2), respectively, is described. 1 and 2 are available in yields of about 50 percent by the reaction of an excess of methylene bromide with triisopropylphosphite or diisopropyl phenylphosphonite, respectively.The metalation of the symmetrical and unsymmetrical diphosphorylmethanes 3-8 with NaH in toluene yields the corresponding carbanionic salts 3A-8A.Their structure and reactivity are investigated by means of 31P NMR spectroscopy and Horner-reactions with benzaldehyde.Regioselective monomethylation at the central carbon atom of 3-7 is performed using the phase-transfer technique.With exception of the phosphono-phosphinate derivative 14, on this way the appropriate 1,1-diphosphorylethanes 13 and 15-17 are obtained in high yield.Key words: diisopropyl bromomethylphosphonate; isopropyl phenyl-bromomethylphosphinate; diphosphorylmethanes; 31P-NMR; HORNER-reactions; 1,1-diphosphorylethanes
Goebel, R.,Richter, F.,Weichmann, H.
p. 67 - 80
(2007/10/02)

UNUSUAL TRANSFORMATION OF (DIPHENYLPHOSPHINYL)ACETIC ACID
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Frolovskii, V. A.,Studnev, Yu. N.,Rozantsev, G. G.
p. 783
(2007/10/02)

Reactions of P_Cl compounds in presence of SMI2
Conversion of P-Cl to P-H and P-C bonds are induced by SmI2 in mild conditions. Especially phosphines oxides and sulfides are obtained in good yields.
Sasaki, Mitsuru,Collin, Jacqueline,Kagan, Henri B.
p. 2493 - 2496
(2007/10/02)

Photochemical Anion-Promoted Carbon-Sulfur Cleavage Reactions of Diaryl Sulfides, Alkyl Aryl Sulfides, and Related Sulfoxides and Sulfones
Diaryl sulfides and the related sulfoxides and sulfones react with substances such as diethyl phosphite anion, pinacolone enolate, and diphenylphosphide anion under irradiation to cleave one carbon-sulfur bond and form diethyl arylphosphonates, arylmethyl tert-butyl ketones, and aryldiphenylphosphines.Alkyl aryl sulfides and the related sulfones also experience carbon-sulfur bond cleavage under these conditions to produce arenethiols.Generally, these reactions occur in synthetically useful yields.The reactions of the anions with these sulfides, sulfoxides, and sulfones all require irradiation, but is notable that the reactions of diphenylphosphide anion occur in the visible region of the spectrum.Several lines of evidence suggest that the reaction proceeds via the familiar SRN1 pathway and that the photochemically-induced electron transfer occurs in an arene-anion complex.Thermochemical considerations dictate the cleavage direction in the anion radicals of unsymmetrical sulfides.
Cheng, Carlos,Stock, Leon M.
p. 2436 - 2443
(2007/10/02)