6163-58-2Relevant articles and documents
A family of rhodium and iridium complexes with semirigid benzylsilyl phosphines: From bidentate to tetradentate coordination modes
Corona-González, María Vicky,Zamora-Moreno, Julio,Cuevas-Chávez, Cynthia A.,Rufino-Felipe, Ernesto,Mothes-Martin, Emmanuelle,Coppel, Yannick,Mu?oz-Hernández, Miguel A.,Vendier, Laure,Flores-Alamo, Marcos,Grellier, Mary,Sabo-Etienne, Sylviane,Montiel-Palma, Virginia
, p. 8827 - 8838 (2017)
The synthesis of a new trisbenzylsilanephosphine P{(o-C6H4CH2)SiMe2H}3 (1) is shown to proceed with high yields from P(o-tolyl)3. Compound 1 coordinates to the Rh and Ir dimers [MCl(COD)]2 (M = Rh, Ir) in a tetradentate or tridentate fashion, depending on the strict exclusion of water. The dimeric compounds [ClM(SiMe2CH2-o-C6H4)2P(o-C6H4-CH2SiMe2H)]2, 2Rh and 2Ir, feature a tetradentate coordination of the starting ligand with P and two Si atoms as well as a non-classical agostic Si-H group. The presence of adventitious water in the solvents leads to the formation of two new complexes [(μ2-Cl)2M2(SiMe2CH2-o-C6H4)2P(o-C6H4-CH2SiMe2OSiMe2CH2-o-C6H4-)P(SiMe2CH2-o-C6H4)2], 3Rh and 3Ir, which feature a siloxane bridge through Si-H bond breaking in 2. Reaction of [RhCl(COD)]2 with the bisbenzylsilanephosphine PhP{(o-C6H4CH2)SiMe2H}2 leads to the formation of compound 4Rh which features also a dimeric structure with the SiPSi ligand coordinated through the two silicon atoms, one of which occupies the apical position of a square-pyramidal geometry in the solid state, while the second is disposed equatorially trans to π-donor Cl. Finally, bidentate coordination of a PSi ligand is achieved by reaction of [RhCl(COD)]2 with Ph2P{(o-C6H4CH2)SiMe2H} which leads to the monometallic species [RhCl(SiMe2CH2-o-C6H4-PPh2)2], 5Rh, incorporating two chelating PSi ligands and maintaining a Cl ligand.
Kinetics and Equilibrium of the Reaction between Bis(trifluoroacetylacetonato)palladium(II) and Tri-o-tolylphosphine
Matsumoto, Shinichi,Kawaguchi, Shinichi
, p. 1704 - 1707 (1981)
Tri-o-tolylphosphine reacts with bis(trifluoroacetylacetonato)palladium(II), Pd(tfac)2, to convert one of the chelating ligands into the unidentate state, resulting in Pd(tfac)(tfac-O)P(o-tolyl)3.The reaction was studied by a spectrophotometric method.The equilibrium constant was determined at several temperatures, K being 1.38*103, 4.35*103 dm3 mol-1 and more than 109 dm3 mol-1 in benzene, dichloromethane, and methanol, respectively, at 25 deg C.In the presence of excess phosphine, the reaction proceeds as a pseudo first order reaction to attain equilibrium.The forward and reverse rate constants, k1 and k-1, were obtained as 0.172 dm3 mol-1 s-1 and 1.22*10-4 s-1 in benzene and 2.28 dm3 mol-1 s-1 and 4.9*10-4 s-1 in dichloromethane at 25 deg C, respectively.In methanol the forward rate was measured under irreversible pseudo first order conditions and conforms with the usual two term rate law, kobsd/s-1=2*10-3 + 56.6.The remarkable dependence of K and k1 on the nature of solvent is related to the hydrogen bonding interaction between the carbonyl group of the coordinated tfac anion and a solvent molecule.
Photochemical transformation of chlorobenzenes and white phosphorus into arylphosphines and phosphonium salts
Gschwind, Ruth M.,Mende, Michael,Scott, Daniel J.,Streitferdt, Verena,Till, Marion,Wolf, Robert
supporting information, p. 1100 - 1103 (2022/02/03)
Chlorobenzenes are important starting materials for the preparation of commercially valuable triarylphosphines and tetraarylphosphonium salts, but their use for the direct arylation of elemental phosphorus has been elusive. Here we describe a simple photochemical route toward such products. UV-LED irradiation (365 nm) of chlorobenzenes, white phosphorus (P4) and the organic superphotoreductant tetrakis(dimethylamino)ethylene (TDAE) affords the desired arylphosphorus compounds in a single reaction step.
A Lewis Base Nucleofugality Parameter, NFB, and Its Application in an Analysis of MIDA-Boronate Hydrolysis Kinetics
Taylor, Nicholas P.,Gonzalez, Jorge A.,Nichol, Gary S.,García-Domínguez, Andrés,Leach, Andrew G.,Lloyd-Jones, Guy C.
supporting information, p. 721 - 729 (2022/01/04)
The kinetics of quinuclidine displacement of BH3 from a wide range of Lewis base borane adducts have been measured. Parameterization of these rates has enabled the development of a nucleofugality scale (NFB), shown to quantify and predict the leaving group ability of a range of other Lewis bases. Additivity observed across a number of series R′3-nRnX (X = P, N; R′ = aryl, alkyl) has allowed the formulation of related substituent parameters (nfPB, nfAB), providing a means of calculating NFB values for a range of Lewis bases that extends far beyond those experimentally derived. The utility of the nucleofugality parameter is explored by the correlation of the substituent parameter nfPB with the hydrolyses rates of a series of alkyl and aryl MIDA boronates under neutral conditions. This has allowed the identification of MIDA boronates with heteroatoms proximal to the reacting center, showing unusual kinetic lability or stability to hydrolysis.
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.).
Photocatalytic Arylation of P4 and PH3: Reaction Development Through Mechanistic Insight
Cammarata, Jose,Gschwind, Ruth M.,Lennert, Ulrich,Rothfelder, Robin,Scott, Daniel J.,Streitferdt, Verena,Wolf, Robert,Zeitler, Kirsten
supporting information, p. 24650 - 24658 (2021/10/14)
Detailed 31P{1H} NMR spectroscopic investigations provide deeper insight into the complex, multi-step mechanisms involved in the recently reported photocatalytic arylation of white phosphorus (P4). Specifically, these studies have identified a number of previously unrecognized side products, which arise from an unexpected non-innocent behavior of the commonly employed terminal reductant Et3N. The different rate of formation of these products explains discrepancies in the performance of the two most effective catalysts, [Ir(dtbbpy)(ppy)2][PF6] (dtbbpy=4,4′-di-tert-butyl-2,2′-bipyridine) and 3DPAFIPN. Inspired by the observation of PH3 as a minor intermediate, we have developed the first catalytic procedure for the arylation of this key industrial compound. Similar to P4 arylation, this method affords valuable triarylphosphines or tetraarylphosphonium salts depending on the steric profile of the aryl substituents.
Direct and Scalable Electroreduction of Triphenylphosphine Oxide to Triphenylphosphine
Manabe, Shuhei,Sevov, Christo S.,Wong, Curt M.
, p. 3024 - 3031 (2020/03/10)
The direct and scalable electroreduction of triphenylphosphine oxide (TPPO)-the stoichiometric byproduct of some of the most common synthetic organic reactions-to triphenylphosphine (TPP) remains an unmet challenge that would dramatically reduce the cost and waste associated with performing desirable reactions that are mediated by TPP on a large scale. This report details an electrochemical methodology for the single-step reduction of TPPO to TPP using an aluminum anode in combination with a supporting electrolyte that continuously regenerates a Lewis acid from the products of anodic oxidation. The resulting Lewis acid activates TPPO for reduction at mild potentials and promotes P-O over P-C bond cleavage to selectively form TPP over other byproducts. Finally, this robust methodology is applied to (i) the reduction of synthetically useful classes of phosphine oxides, (ii) the one-pot recycling of TPPO generated from a Wittig reaction, and (iii) the gram-scale reduction of TPPO at high concentration (1 M) with continuous product extraction and in flow at high current density.
Substituent steric effect boosting phosphorescence efficiency of PtCu2 complexes
Chen, Zhong-Ning,Wang, Jin-Yun,Wang, Zhao-Yi,Yang, Ming,Zhang, Li-Yi,Zhang, Xu
supporting information, p. 5174 - 5182 (2020/04/28)
We describe herein a viable approach to enhance phosphorescence efficiency in PtCu2 complexes with aromatic acetylides by the use of bis(di-2-tolylphosphinomethyl)phenylphosphine (dTolmp) in place of bis(diphenylphosphinomethyl)-phenylphosphine (dpmp) as a supporting ligand. Relative to dpmp-supported PtCu2 complexes, dTolmp-supported complexes having the same acetylide ligands show not only a 16-36 nm red-shift of the emission peaks, but also a dramatic phosphorescence enhancement. The phosphorescence quantum yields of dTolmp-supported PtCu2 complexes are boosted to 6.6 and 11.6 times as high as those of the dpmp-supported ones in CH2Cl2 solutions and the solid state, respectively. From dpmp to dTolmp, introducing sterically hindered 2-methyl groups to phenyl rings not only improves the π-conjugation character of PtCu2 complexes, but also effectively inhibits the deactivation process of the triplet excited state through non-radiative relaxation. The phosphorescence properties were systematically modulated in a wide spectral range from 502 to 672 nm by introducing electron-donating or electron-withdrawing substituents into aromatic acetylides.
Versatile Visible-Light-Driven Synthesis of Asymmetrical Phosphines and Phosphonium Salts
Arockiam, Percia Beatrice,Lennert, Ulrich,Graf, Christina,Rothfelder, Robin,Scott, Daniel J.,Fischer, Tillmann G.,Zeitler, Kirsten,Wolf, Robert
supporting information, p. 16374 - 16382 (2020/11/03)
Asymmetrically substituted tertiary phosphines and quaternary phosphonium salts are used extensively in applications throughout industry and academia. Despite their significance, classical methods to synthesize such compounds often demand either harsh reaction conditions, prefunctionalization of starting materials, highly sensitive organometallic reagents, or expensive transition-metal catalysts. Mild, practical methods thus remain elusive, despite being of great current interest. Herein, we describe a visible-light-driven method to form these products from secondary and primary phosphines. Using an inexpensive organic photocatalyst and blue-light irradiation, arylphosphines can be both alkylated and arylated using commercially available organohalides. In addition, the same organocatalyst can be used to transform white phosphorus (P4) directly into symmetrical aryl phosphines and phosphonium salts in a single reaction step, which has previously only been possible using precious metal catalysis.
Superbase-Assisted Selective Synthesis of Triarylphosphines from Aryl Halides and Red Phosphorus: Three Consecutive Different SNAr Reactions in One Pot
Malysheva, Svetlana F.,Kuimov, Vladimir A.,Belogorlova, Natalia A.,Albanov, Alexander I.,Gusarova, Nina K.,Trofimov, Boris A.
supporting information, p. 6240 - 6245 (2019/11/05)
Aryl halides, ArX (Ar = Ph, 2-, 3- and 4-Tol, 1- and 2-Np, 4-C6H4CONH2; X = F, Cl, Br), rapidly and exothermically (100–180 °C, 0.5–2 h) react with red phosphorus in superbase systems KOH/L, where L is a polar nonhydroxylic complexing solvent (ligand), such as NMP, DMSO, HMPA, to afford the corresponding triarylphosphines (Ar3P) in up to 74 % yield (for X = F). Thus, three consecutive reactions of SNAr (aromatic nucleophilic substitution) to form the three C(sp2)–P bonds are realized in one pot. The synthesis is mostly chemoselective (with rare exception): neither mono- nor diphosphines have been isolated. The best results were attained when aryl fluorides were treated with red phosphorus (Pn) in the KOH/NMP superbase system. This environmentally friendly, PCl3-free synthesis of Ar3P from available starting materials opens an easy and straightforward access to triarylphosphines, which are important ligands, synthetic auxiliaries, and components of high-tech- and medicinally oriented complexes.
