2129-89-7Relevant academic research and scientific papers
Synthesis of stable carboxylate phosphabetaines - Potential ligands of the metal complexes
Galkina, Irina,Romanov, Semyon,Gerasimov, Alexander,Bakhtiyarova, Yulia,Galkin, Vladimir
, (2020)
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.
Voltage Imaging with a NIR-Absorbing Phosphine Oxide Rhodamine Voltage Reporter
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)
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.
Acetylacetonate and Acetate Complexes of Nickel(II) Catalyse the Air Oxidation of Phosphines
Hansen, Line Sofie,Jakobsen, Vibe Boel,McKee, Vickie,McKenzie, Christine J.
, p. 4163 - 4169 (2020)
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.
Anionic Phosphorus as a Nucleophile. An Anion Chain Arbuzov Mechanism
Spears, L. Gene,Liao, Andrew,Minsek, David,Lewis, Edward S.
, p. 61 - 64 (1987)
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.
Alkoxyphosphonium ions. 5. Kinetics of the Michaelis-Arbuzov intermediate
Lewis, Edward S.,McCortney, Briget A.
, p. 1156 - 1160 (1986)
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.
The Trityl-Cation Mediated Phosphine Oxides Reduction
Landais, Yannick,Laye, Claire,Lusseau, Jonathan,Robert, Frédéric
supporting information, p. 3035 - 3043 (2021/05/10)
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.).
Evaluation of bifunctional chiral phosphine oxide catalysts for the asymmetric hydrosilylation of ketimines
Warner, Christopher J.A.,Berry, Sian S.,Jones, Simon
, (2019/11/11)
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%.
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
Li, Chunya,Wang, Qi,Zhang, Jian-Qiu,Ye, Jingjing,Xie, Ju,Xu, Qing,Han, Li-Biao
supporting information, p. 2916 - 2922 (2019/06/18)
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.
Hydrotrifluoromethylthiolation of Unactivated Alkenes and Alkynes with Trifluoromethanesulfonic Anhydride through Deoxygenative Reduction and Photoredox Radical Processes
Ouyang, Yao,Xu, Xiu-Hua,Qing, Feng-Ling
supporting information, p. 18508 - 18512 (2019/11/14)
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.
Phosphine Oxidation with Water and Ferrocenium(III) Cation Induced by Visible-Light Irradiation
Tanabe, Yoshiaki,Nakajima, Kazunari,Nishibayashi, Yoshiaki
supporting information, p. 18618 - 18622 (2018/11/30)
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.
