- Reaction of secondary phosphine chalcogenides with diallylamine
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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
- Verkhoturova,Kazantseva,Arbuzova,Albanov,Gusarova,Trofimov
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- Indium(III) promoted oxidative P-P coupling of silylphosphines
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The reaction of indium(III) salts with Ph2PSiMe3 and PhP(SiMe3)2 gives rise to a one- and two-electron reductive P-P coupling respectively, with the formation of new P-P bonds resulting in the preparation of (Ph2P)2 and the cyclicoligophosphane compounds (PhP)4 and (PhP)6.
- Cartlidge, Ashleigh J.,Matthews, Peter D.
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- Phosphirenium ions as masked phosphenium Catalysts: Mechanistic evaluation and application in synthesis
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The utilization of phosphirenium ions is presented; optimized and broadened three-membered ring construction is described together with the use of these ions as efficient pre-catalysts for metal-free carbonyl reduction with silanes. Full characterization of the phosphirenium ions is presented, and initial experimental and computational mechanistic studies indicate that these act as a "masked phosphenium"source that is accessed via ring opening. Catalysis proceeds via associative transfer of {Ph2P+} to a carbonyl nucleophile, Ha'SiR3 bond addition over the C=O group, and associative displacement of the product by a further equivalent of the carbonyl substrate, which completes the catalytic cycle. A competing off-cycle process leading to vinyl phosphine formation is detailed for the hydrosilylation of benzophenone for which an inverse order in [silane] is observed. Experimentally, the formation of side products, including off-cycle vinyl phosphine, is favored by electrondonating substituents on the phosphirenium cation, while catalytic hydrosilylation is promoted by electron-withdrawing substituents. These observations are rationalized in parallel computational studies.
- Gasperini, Danila,Neale, Samuel E.,Mahon, Mary F.,MacGregor, Stuart A.,Webster, Ruth L.
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p. 5452 - 5462
(2021/06/01)
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- The Trityl-Cation Mediated Phosphine Oxides Reduction
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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
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supporting information
p. 3035 - 3043
(2021/05/10)
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- Reversing Lewis acidity from bismuth to antimony
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Investigations on the boundaries between the neutral and cationic models of (Mesityl)2EX (E = Sb, Bi and X = Cl?, OTf?) have facilitated reversing the Lewis acidity from bismuth to antimony. We use this concept to demonstrate a higher efficiency of (Mesityl)2SbOTf(Mesityl)2BiOTf in the catalytic reduction of phosphine oxides to phosphines. The experiments supported with computations described herein will find use in designing new Lewis acids relevant to catalysis.
- Balasubramaniam, Selvakumar,Jemmis, Eluvathingal D.,Kumar, Sandeep,Sharma, Deepti,Venugopal, Ajay
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supporting information
p. 8889 - 8892
(2021/09/10)
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- Photocatalytic Arylation of P4 and PH3: Reaction Development Through Mechanistic Insight
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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.
- Cammarata, Jose,Gschwind, Ruth M.,Lennert, Ulrich,Rothfelder, Robin,Scott, Daniel J.,Streitferdt, Verena,Wolf, Robert,Zeitler, Kirsten
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supporting information
p. 24650 - 24658
(2021/10/14)
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- 2-Phenoxyethyldiphenylphosphine oxide as an equivalent of diphenylvinylphosphine oxide in nucleophilic additions
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A facile method for the synthesis of β-functionalized ethyldiphenylphosphine oxides is developed based on readily available 2-phenoxyethyldiphenylphosphine oxide used as an equivalent of diphenylvinylphosphine oxide in the reactions of addition of different PH- and NH-nucleophiles in DMSO in the presence of KOH. The transformations of labile phosphine oxides of a general formula Ph2P(O)CH2CH2OR, where R = Ph, H, or Ph2P(O)CH = CH2, in aq.KOH/DMSO and solid KOH/DMSO systems are explored in the absence of nucleophilic reagents.
- Bondarenko, Natalia A.,Tcarkova, Kseniia V.,Belus', Svetlana K.,Artyushin, Oleg I.
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p. 902 - 910
(2021/06/25)
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- Process for preparation of phosphorane and phosphonyl compounds
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The invention relates to the field of new materials of fine chemicals, in particular to a new safe, convenient, mild, efficient, environment-friendly and economical preparation process technology of phosphorane and phosphonyl compounds.
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Paragraph 0031-0033
(2021/06/06)
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- One-pot synthesis of binaphthyl-based phosphines via direct modification of BINAP
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Herein reported is the convenient and efficient strategy for the preparation of binaphthyl-based phosphines through direct modification to the commercially available 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (BINAP) with sodium. In the absence of 15-crown-5-ether, a cyclic sodium dinapthylphospholide intermediate is mainly generated. With 15-crown-5-ether, P-Ph bonds are selectively cleft by Na to produce binaphthyl-based disodium phosphides. The mechanism of selective formation of sodium dinapthylphospholide or binaphthyl-based disodium phosphides is proposed.
- Ye, Jing-Jing,Zhang, Jian-Qiu,Shimada, Shigeru,Han, Li-Biao
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supporting information
(2021/11/18)
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- Mild intramolecular P–C(sp3) bond cleavage in bridging diphosphine complexes of RuII RhIII and IrIII
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Three new carboxylic acid functionalised diphosphines, R2PCH2N(Ar)CH2PR2 [CyL1 R = Cy, Ar = (1-CO2H)(3-OMe)C6H3, CyL2 R = Cy, Ar = (1-CO2H)(3-OH)C6H3 and PhL3 R = Ph, Ar = (1-CO2H)(5-OMe)C6H3] have been prepared from condensation of R2PCH2OH and the appropriate aromatic amine in MeOH, and isolated as colourless solids (for CyL1, CyL2) in good yield. Reaction of CyL1, CyL2, or PhL3, along with the previously reported diphosphines PhL1, PhL2, and PhL4, and [RuCl(μ-Cl)(η6-Me2CHC6H4Me)]2 in CH2Cl2 affords the P/P-bridging dinuclear ruthenium(II) complexes {RuCl2(η6-Me2CHC6H4Me)}2(μ-CyL1?PhL4) 1a?f as red/orange solids. Careful monitoring by 31P{1H} NMR spectroscopy of CDCl3 solutions of 1a?e revealed remarkably clean P?Csp3 bond cleavage to give RuII mononuclear species 2a?e and the known secondary phosphine complexes RuCl2(η6-Me2CHC6H4Me)(PCy2H) 3 and RuCl2(η6-Me2CHC6H4Me)(PPh2H) 4. Furthermore, facile P?Csp3 bond cleavage of PhL1 can be observed using the chloro-bridged dimers [IrCl(μ-Cl)(η5-C5Me5)]2 or [RhCl(μ-Cl)(η5-C5Me5)]2 instead. Deuterium labelling of CyL1, CyL1, PhL1, and PhL2 enabled the assignment of the methylene protons to be confirmed from 1H NMR spectroscopy. All new compounds have been characterised using a range of spectroscopic and analytical techniques. Single crystal X-ray structures have been determined for CyL1, 1d·3OEt2, 1f·2CDCl3·OEt2, 2b, 2c, 2d·CDCl3, 2e·0.5OEt2 and 6b·1.5CDCl3. The free phenolic group in CyL1, 1d·3OEt2, 1f·2CDCl3·OEt2, 2b and 2d·CDCl3 participates in intra- or intermolecular O?H···O hydrogen bonding.
- De'Ath, Peter,Elsegood, Mark R.J.,Halliwell, Christopher A.G.,Smith, Martin B.
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- Ready Approach to Organophosphines from ArCl via Selective Cleavage of C-P Bonds by Sodium
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The preparation, application, and reaction mechanism of sodium phosphide R2PNa and other alkali metal phosphides R2PM (M = Li and K) have been studied. R2PNa could be prepared, accurately and selectively, via the reactions of SD (sodium finely dispersed in mineral oil) with phosphinites R2POR′ and chlorophosphines R2PCl. R2PNa could also be prepared from triarylphosphines and diarylphosphines via the selective cleavage of C-P bonds. Na was superior to Li and K for these reactions. R2PNa reacted with a variety of ArCl to efficiently produce R2PAr. ArCl is superior to ArBr and ArI since they only gave low yields of the products. In addition, Ph2PNa is superior to Ph2PLi and Ph2PK since Ph2PLi did not produce the coupling product with PhCl, while Ph2PK only gave a low yield of the product. An electron-withdrawing group on the benzene ring of ArCl greatly accelerated the reactions with R2PNa, while an alkyl group reduced the reactivity. Vinyl chloride and alkyl chlorides RCl also reacted efficiently. While t-BuCl did not produce the corresponding product, admantyl halides could give the corresponding phosphine in high yields. A wide range of phosphines were prepared by this method from the corresponding chlorides. Unsymmetric phosphines could also be conveniently generated in one pot starting from Ph3P. Chiral phosphines were also obtained in good yields from the reactions of menthyl chlorides with R2PNa. Possible mechanistic pathways were given for the reductive cleavage of R3P by sodium generating R2PNa and the substitution reactions of R2PNa with ArCl generating R2PAr.
- Ye, Jingjing,Zhang, Jian-Qiu,Saga, Yuta,Onozawa, Shunya,Kobayashi, Shu,Sato, Kazuhiko,Fukaya, Norihisa,Han, Li-Biao
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p. 2682 - 2694
(2020/07/30)
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- Synthesis, Structure, and Solution Studies of Lithiated Allylic Phosphines and Phosphine Oxides
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This study reports a new series of 12 α-lithiated allylic phosphines and phosphine oxides. By incorporating Lewis base donors including diethyl ether (Et2O), tetrahydrofuran (THF), N,N,N′,N′,-tetramethylethylenediamine (TMEDA), and N,N,N′,N′,N″,-pentamethyldiethylenetriamine (PMDETA), nine complexes were structurally characterized by single-crystal X-ray crystallography. This includes novel dilithiated allylic phosphine 4 [PhP{CHCHCH2Li(TMEDA)}2] and a rare hemisolvated lithiated phosphine oxide 6 [{Ph2P(O)CHC(Me)CH2Li}2(TMEDA)]. Interestingly, in the solid state, P(III) complexes take advantage of Li-πinteractions to the newly formed delocalized system, in comparison to P(V) complexes where the oxophillic nature of the lithium atom dominates. All 12 complexes were fully characterized in the solution state by multinuclear NMR spectroscopy. DFT calculations on isomers of monomeric lithiated complex 3 [Ph2PCHC(Me)CH2Li(PMDETA)] described the low energy barrier between transition steps of the subtle delocalization of the allylic chain.
- Eren, Nimrod M.,Orr, Samantha A.,Thompson, Christopher D.,Border, Emily C.,Stevens, Michael A.,Blair, Victoria L.
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supporting information
p. 2080 - 2090
(2020/06/05)
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- Role of Phosphine Sterics in Strained Aminophosphine Chelate Formation
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The preparation of four-membered aminophosphine (PN) chelates from common metal precursors has largely evaded realization because of the ring strain associated with these species. We report a straightforward approach to the synthesis of such PN metallacycles using simple α-PN ligands analogous to the popular class of small-bite-angle diphosphinomethane ligands. It is demonstrated that bulky phosphine substituents are important to the formation of these chelates.
- Bowes, Eric G.,Dawson Beattie,Love, Jennifer A.
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supporting information
p. 2925 - 2929
(2019/03/02)
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- Reductive Elimination at Carbon under Steric Control
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It has been previously demonstrated that stable singlet electrophilic carbenes can behave as metal surrogates in the activation of strong E-H bonds (E = H, B, N, Si, P), but it was believed that these activations only proceed through an irreversible activation barrier. Herein we show that, as is the case with transition metals, the steric environment can be used to promote reductive elimination at carbon centers.
- Tolentino, Daniel R.,Neale, Samuel E.,Isaac, Connie J.,MacGregor, Stuart A.,Whittlesey, Michael K.,Jazzar, Rodolphe,Bertrand, Guy
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supporting information
p. 9823 - 9826
(2019/07/04)
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- Copper-catalyzed C–P cross-coupling of secondary phosphines with (hetero)aromatic bromide
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A novel and convenient approach to the synthesis of various tertiary phosphines via a copper-catalyzed cross-coupling of (hetero)aromatic bromide with secondary phosphines has been developed. The reaction employs cheap copper as the catalyst, 2,6-bis(N-methylaminomethyl)pyridine (L4) as a perfect ligand and KOtBu as a base; all reactions are carried out under argon atmosphere. A variety of sterically hindered and/or functionalized substrates were found to react under these reaction conditions to provide products in good to excellent yields. Moreover, ten new tertiary phosphines were first reported in this process.
- Li, Chun-Jing,Lü, Jing,Zhang, Zhi-Xun,Zhou, Kun,Li, Yan,Qi, Guang-Hui
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p. 4547 - 4562
(2018/04/20)
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- Rapid Metal-Free Formation of Free Phosphines from Phosphine Oxides
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A rapid method for the reduction of secondary phosphine oxides under mild conditions has been developed, allowing simple isolation of the corresponding free phosphines. The methodology involves the use of pinacol borane (HBpin) to effect the reduction while circumventing the formation of a phosphine borane adduct, as is usually the case with various other commonly used borane reducing agents such as borane tetrahydrofuran complex (BH3?THF) and borane dimethyl sulfide complex (BH3?SMe2). In addition, this methodology requires only a small excess of reducing agent and therefore compares favourably not just with other borane reductants that do not require a metal co-catalyst, but also with silane and aluminium based reagents. (Figure presented.).
- Provis-Evans, Cei B.,Emanuelsson, Emma A. C.,Webster, Ruth L.
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supporting information
p. 3999 - 4004
(2018/09/21)
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- Exploring the Reactivity of Donor-Stabilized Phosphenium Cations: Lewis Acid-Catalyzed Reduction of Chlorophosphanes by Silanes
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Phosphane-stabilized phosphenium cations react with silanes to effect either reduction to primary or secondary phosphanes, or formation of P-P bonded species depending upon counteranion. This operates for in situ generated phosphenium cations, allowing catalytic reduction of P(III)-Cl bonds in the absence of strong reducing agents. Anion and substituent dependence studies have allowed insight into the competing mechanisms involved.
- Pearce, Kyle G.,Borys, Andryj M.,Clark, Ewan R.,Shepherd, Helena J.
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supporting information
p. 11530 - 11536
(2018/09/21)
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- Synthesis and properties of heterobimetallic rhodium complexes featuring LiI, CuI or ZnII as a Lewis acidic metalloligand
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A series of [(PMP)Rh(CO)Cl]n+ complexes was synthesised and the impact of the metalloligands CuI, LiI and ZnII on the CO stretching band was analysed.
- Steinhoff, Patrick,Steinbock, Ralf,Friedrich, Anna,Schieweck, Benjamin G.,Cremer, Christopher,Truong, Khai-Nghi,Tauchert, Michael E.
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supporting information
p. 10439 - 10442
(2018/08/17)
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- A Universally Applicable Methodology for the Gram-Scale Synthesis of Primary, Secondary, and Tertiary Phosphines
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Although organophosphine syntheses have been known for the better part of a century, the synthesis of phosphines still represents an arduous task for even veteran synthetic chemists. Phosphines as a class of compounds vary greatly in their air sensitivity, and the misconception that it is trivial or even easy for a novice chemist to attempt a seemingly straightforward synthesis can have disastrous results. To simplify the task, we have previously developed a methodology that uses benchtop intermediates to access a wide variety of phosphine oxides (an immediate precursor to phosphines). This synthetic approach saves the air-free handling until the last step (reduction to and isolation of the phosphine). Presented herein is a complete general procedure for the facile reduction of phosphonates, phosphinates, and phosphine oxides to primary, secondary, and tertiary phosphines using aluminum hydride reducing agents. The electrophilic reducing agents (iBu)2AlH and AlH3 were determined to be vastly superior to LiAlH4 for reduction selectivity and reactivity. Notably, it was determined that AlH3 is capable of reducing the exceptionally resistant tricyclohexylphosphine oxide, even though LiAlH4 and (iBu)2AlH were not. Using this new procedure, gram-scale reactions to synthesize a representative range of primary, secondary, and tertiary phosphines (including volatile phosphines) were achieved reproducibly with excellent yields and unmatched purity without the need for a purification step.
- Rinehart, N. Ian,Kendall, Alexander J.,Tyler, David R.
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p. 182 - 190
(2018/02/06)
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- Cationic Group 4 Complexes (M = Ti, Zr, Hf): Modifications and Limitations in the Design of Tridentate Cp,O,P-Ligand Frameworks Built Directly in the Coordination Sphere of the Metal
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The reactions of monopentafulvene complexes Ti1, Zr1, and Hf1 with bidentate O,P-ligand precursors L1–L3 to form the corresponding cationic complexes employing an established three-step synthetic protocol [insertion, methylation, activation with B(C6F5)3] are investigated. Ligands L1–L3 are designed to have different sized spacers between the carbonyl and diphenylphosphine functional groups. The attempts to react Ti1, Zr1, and Hf1 with acetyldiphenylphosphine (L1) proved to yield undesired products at various steps in the synthetic sequence. When Ti1 is used, Ti2 is formed and diphenylphosphine is released at the same time. Compound Ti2, with the exocyclic double bond, is the formal product of insertion of the smallest ketene (H2C=C=O) into the Ti–Cexo bond. Starting with Zr1 results in isolation of the insertion product Zr2 without loss of diphenylphosphine, but a byproduct is formed during the reaction with L1. Subsequent methylation with methyllithium yields a complex reaction mixture. Hf1 reacts cleanly with L1 to the insertion product Hf2. Also, the methylation reaction selectively yields Hf3 as the result of chloride/methyl exchange, but final activation with B(C6F5)3 causes decomposition and release of diphenylphosphine. The use of the ligand precursors L2 and L3 with two methylene groups or an aryl group as linkers between the functional groups selectively provides the desired cationic complexes Ti6, Zr6, Hf6, and Ti9 in good to excellent overall yields.
- Fischer, Malte,Jaugstetter, Maximilian,Schaper, Raoul,Schmidtmann, Marc,Beckhaus, Rüdiger
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supporting information
p. 5146 - 5159
(2018/11/23)
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- Reactions of Low-Coordinate Cobalt(0)-N-Heterocyclic Carbene Complexes with Primary Aryl Phosphines
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Aiming to get knowledge on the reactivity of low-coordinate cobalt(0) species toward primary phosphines, the reactions of [(IPr)Co(vtms)2] and [(ICy)2Co(vtms)] (IPr = 1,3-bis(2′,6′-diisopropylphenyl)imidazol-2-ylidene, ICy = 1,3-dicyclohexylimidazol-2-ylidene, and vtms = vinyltrimethylsilane) with several primary aryl phosphines have been examined. The reactions of [(IPr)Co(vtms)2] and [(ICy)2Co(vtms)] with H2PDmp (Dmp = 2,6-dimesitylphenyl) at 80 °C furnish the diamagnetic cobalt(I) phosphido complexes [(NHC)Co(PHDmp)] (NHC = IPr, 1; ICy, 2) that feature the Co-(η6-mesityl) interaction. Complex 1 can coordinate CO to generate the terminal phosphido complex [(IPr)Co(CO)3(PHDmp)] (3) and can be oxidized by [Cp2Fe][BArF4] to yield the cobalt(II) phosphido complex [(IPr)Co(PHDmp)][BArF4] (4, BArF4 = tetrakis(3,5-di(trifluoromethyl)phenyl)borate). For the reactions with sterically less-hindered primary phosphines, [(IPr)Co(vtms)2] is inert toward H2PC6H2-2,4,6-Me3 (H2PMes) at room temperature, whereas [(ICy)2Co(vtms)] can react with H2PMes at room temperature to produce the cobalt(II) phosphido alkyl complex trans-[(ICy)2Co(CH2CH2SiMe3)(PHMes)] (5). At 80 °C, the cobalt(0) alkene complexes [(IPr)Co(vtms)2] and [(ICy)2Co(vtms)] and also the cobalt phosphido complexes, 1, 2, and 5 can serve as precatalysts for the dehydrocoupling reaction of H2PMes to afford MesHPPHMes. NHC-Co(I)-phosphido species are proposed as the in-cycle intermediates for these cobalt-catalyzed dehydrocoupling reactions.
- Wang, Dongyang,Chen, Qi,Leng, Xuebing,Deng, Liang
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supporting information
p. 15600 - 15609
(2019/01/04)
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- Direct Electrochemical P(V) to P(III) Reduction of Phosphine Oxide Facilitated by Triaryl Borates
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Triaryl borate Lewis acids facilitate the direct two-electron reduction of the P(V) center of triphenylphosphine oxide (TPPO) to the P(III) center of triphenylphosphine at faradaic efficiencies of 37%. Insight from direct P(V) to P(III) reduction is provided from cyclic voltammetry. The electrochemical reduction of TPPO proceeds through an unusual ECrECi mechanism in which the breaking of the phosphoryl bond in a two-electron-reduced association complex with the triaryl borate is rate-determining. The rate and faradaic efficiency for TPPO reduction are tuned by judicious choice of substituents on triaryl borate, with tris(4-methoxyphenyl) borate demonstrating the highest for both. These results suggest that an attractive route toward the roomerature reduction of phosphate for phosphorus reclamation is greatly facilitated by the stabilization of reduced phosphate intermediates through their association with Lewis acids.
- Elias, Joseph S.,Costentin, Cyrille,Nocera, Daniel G.
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supporting information
p. 13711 - 13718
(2018/10/24)
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- A Versatile Approach for Site-Specific Lysine Acylation in Proteins
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Using amber suppression in coordination with a mutant pyrrolysyl-tRNA synthetase-tRNAPylpair, azidonorleucine is genetically encoded in E. coli. Its genetic incorporation followed by traceless Staudinger ligation with a phosphinothioester allows the convenient synthesis of a protein with a site-specifically installed lysine acylation. By simply changing the phosphinothioester identity, any lysine acylation type could be introduced. Using this approach, we demonstrated that both lysine acetylation and lysine succinylation can be installed selectively in ubiquitin and synthesized histone H3 with succinylation at its K4 position (H3K4su). Using an H3K4su-H4 tetramer as a substrate, we further confirmed that Sirt5 is an active histone desuccinylase. Lysine succinylation is a recently identified post-translational modification. The reported technique makes it possible to explicate regulatory functions of this modification in proteins.
- Wang, Zhipeng A.,Kurra, Yadagiri,Wang, Xin,Zeng, Yu,Lee, Yan-Jiun,Sharma, Vangmayee,Lin, Hening,Dai, Susie Y.,Liu, Wenshe R.
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supporting information
p. 1643 - 1647
(2017/02/05)
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- Chemoselective Reduction of Phosphine Oxides by 1,3-Diphenyl-Disiloxane
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Reduction of phosphine oxides to the corresponding phosphines represents the most straightforward method to prepare these valuable reagents. However, existing methods to reduce phosphine oxides suffer from inadequate chemoselectivity due to the strength of the P=O bond and/or poor atom economy. Herein, we report the discovery of the most powerful chemoselective reductant for this transformation to date, 1,3-diphenyl-disiloxane (DPDS). Additive-free DPDS selectively reduces both secondary and tertiary phosphine oxides with retention of configuration even in the presence of aldehyde, nitro, ester, α,β-unsaturated carbonyls, azocarboxylates, and cyano functional groups. Arrhenius analysis indicates that the activation barrier for reduction by DPDS is significantly lower than any previously calculated silane reduction system. Inclusion of a catalytic Br?nsted acid further reduced the activation barrier and led to the first silane-mediated reduction of acyclic phosphine oxides at room temperature.
- Buonomo, Joseph A.,Eiden, Carter G.,Aldrich, Courtney C.
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supporting information
p. 14434 - 14438
(2017/10/23)
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- Metal-Free Reduction of Phosphine Oxides, Sulfoxides, and N-Oxides with Hydrosilanes using a Borinic Acid Precatalyst
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The general reduction of phosphine oxides, sulfoxides, and amine N-oxides was achieved by combining bis(2-chlorophenyl)borinic acid with phenylsilane. The reaction was shown to tolerate a wide range of substrates and could be performed under mild conditions, with only 2.5 mol % of the easily synthesized catalyst. Mechanistic investigations pointed to a key borohydride as the real catalyst and at bis(2-chlorophenyl)borinic acid as a precatalyst.
- Chardon, Aurélien,Maubert, Orianne,Rouden, Jacques,Blanchet, Jér?me
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p. 4460 - 4464
(2017/11/22)
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- Non-Metal-Catalyzed Heterodehydrocoupling of Phosphines and Hydrosilanes: Mechanistic Studies of B(C6F5)3-Mediated Formation of P-Si Bonds
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Non-metal-catalyzed heterodehydrocoupling of primary and secondary phosphines (R1R2PH, R2 = H or R1) with hydrosilanes (R3R4R5SiH, R4, R5 = H or R3) to produce synthetically useful silylphosphines (R1R2P-SiR3R4R5) has been achieved using B(C6F5)3 as the catalyst (10 mol %, 100 °C). Kinetic studies demonstrated that the reaction is first-order in hydrosilane and B(C6F5)3 but zero-order in phosphine. Control experiments, DFT calculations, and DOSY NMR studies suggest that a R1R2HP·B(C6F5)3 adduct is initially formed and undergoes partial dissociation to form an "encounter complex". The latter mediates frustrated Lewis pair type Si-H bond activation of the silane substrates. We also found that B(C6F5)3 catalyzes the homodehydrocoupling of primary phosphines to form cyclic phosphine rings and the first example of a non-metal-catalyzed hydrosilylation of P-P bonds to produce silylphosphines (R1R2P-SiR3R4R5). Moreover, the introduction of PhCN to the reactions involving secondary phosphines with hydrosilanes allowed the heterodehydrocoupling reaction to proceed efficiently under much milder conditions (1.0 mol % B(C6F5)3 at 25 °C). Mechanistic studies, as well as DFT calculations, revealed that PhCN plays a key mechanistic role in facilitating the dehydrocoupling reactions rather than simply functioning as H2-acceptor.
- Wu, Lipeng,Chitnis, Saurabh S.,Jiao, Haijun,Annibale, Vincent T.,Manners, Ian
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supporting information
p. 16780 - 16790
(2017/11/28)
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- A highly efficient gas-dominated and water-resistant flame retardant for non-charring polypropylene
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Traditional phosphorus-nitrogen (P-N) flame-retardant systems for polypropylene (PP) always act through joint action of the gaseous phase and condensed phase, and are accompanied with a decrease of the thermal stability and water resistance. In this work, a novel mono-component and gas-dominated flame retardant, named DPPIP, was prepared through an amidation reaction of diphenylphosphinyl chloride and piperazine, and used to flame retard PP. Experimental results confirmed that both the thermal stability and water resistance of PP/DPPIP were improved. The initial thermal decomposition temperature of PP/25 wt% DPPIP at 5 wt% weight loss was 287.5 °C under air atmosphere, which is higher than that of neat PP (266.1 °C). Besides, a water-resistance test verified that PP/25 wt% DPPIP had a weight loss of only about 0.52 wt%. More importantly, the flame retardant ability of PP/25 wt% DPPIP had been greatly improved, passing the V-0 rating (UL-94). Furthermore, after the water-resistance test, the LOI value of PP/25 wt% DPPIP exhibited nearly no difference and still passed the UL-94 V-0 rating. A cone calorimeter (CC) result indicated that DPPIP had a positive effect on inhibiting heat release of PP during combustion. All of these combustion tests displayed that there was no char left. The flame retardant mechanism of DPPIP was investigated with py-GC/MS and TG-FTIR. The results illustrated that the gaseous phase resulting from the thermal decomposition of DPPIP played the leading role in the self-extinguishing behavior of PP/DPPIP, which consisted of a large amount of inflammable gaseous products such as piperazine and its derivatives, and phosphorus-containing structures.
- Shao, Zhu-Bao,Zhang, Ming-Xin,Han, Ye,Yang, Xu-Dong,Jin, Jing,Jian, Rong-Kun
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p. 51919 - 51927
(2017/11/22)
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- Sequential Addition of Phosphine to Alkynes for the Selective Synthesis of 1,2-Diphosphinoethanes under Catalysis. Well-Defined NHC-Copper Phosphides vs in Situ CuCl2/NHC Catalyst
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The well-defined NHC-copper phosphides [(NHC)CuPPh2]3 (1, NHC = 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (IiPr); 2, NHC = N,N-di-tert-butylimidazol-2-ylidene (ItBu)) have been prepared by the reaction of simple copper halides with HPPh2 in the presence of N-heterocyclic carbenes (NHCs). Complexes 1 and 2 enabled catalytic double hydrophosphination of alkyl and aryl terminal alkynes to yield 1,2-diphosphinoethanes selectively in good yields. On the basis of these results, the most efficient and pratical in situ CuCl2/NHC catalyst has been developed. It catalyzes the selective double hydrophosphination of the alkynes with high efficiency and a wide substrate scope and exhibits even better performance than the well-defined NHC-Cu phosphides. The mechanistic studies disclosed that the formation of a copper acetylide in the catalytic cycle played an important role in the acceleration of the catalytic process.
- Yuan, Jia,Zhu, Lizhao,Zhang, Jianying,Li, Jianfeng,Cui, Chunming
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supporting information
p. 455 - 459
(2017/04/26)
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- Phosphanylphosphido and phosphanylphosphinidene complexes of zirconium(IV) supported by bidentate N,N ligands
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Phosphanylphosphido complexes of zirconium, [NacNacZrCl2(η2-R2P–PSiMe3)] (R?=?t-Bu, i-Pr), were synthesized in the reaction of R2P–P(SiMe3)Li·nTHF (R?=?t-Bu, i-Pr) with a β-diketiminate complex, [NacNacZrCl3], in toluene. Elimination of Me3SiCl from [NacNacZrCl2(η2-R2P–PSiMe3)] provided the phosphanylphosphinidene complexes [NacNacZrCl(η2-R2P–P)] (R?=?t-Bu, i-Pr). Moreover, the reaction of [NacNacZrCl2(η2-R2P–PSiMe3)] with R2P–P(SiMe3)Li·nTHF yielded the phosphanylphosphinidenoid complexes [NacNacZrCl2(η2-R2P–PLi)] (R?=?t-Bu, i-Pr). The same reaction, but in the presence of 12-crown-4, gave rise to the phosphanylphosphinidene complexes [NacNacZrCl(η2-R2P–P)]. The X-ray structures of [NacNacZrCl2(η2-i-Pr2P–PSiMe3)] and [NacNacZrCl(η2-t-Bu2P–P)] revealed that the R2P-P ligands exhibit side-on coordination to the metal center. From the reaction of i-Pr2P–P(SiMe3)Li·3THF with [{PhN(CH2)3NPh)}ZrCl2], a triple-core, anionic, phosphanylphosphinidene complex, [{PhN(CH2)3NPh)}Zr3Cl2(μ2-Cl)(μ2-i-Pr2P–P)2(μ3-i-Pr2P–P)2]?[Li(DME)3]+, was obtained in which the i-Pr2P–P ligands exhibit bridging coordination.
- Zauliczny, Mateusz,Grubba, Rafa?,Ponikiewski, ?ukasz,Pikies, Jerzy
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p. 353 - 360
(2017/01/09)
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- Organocatalyzed Reduction of Tertiary Phosphine Oxides
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A novel selective catalytic reduction method of tertiary phosphine oxides to the corresponding phosphines has been developed. Notably, the reaction proceeds smoothly with low catalyst loadings of 1-5 mol% even at low temperature (70 C). Under the optimized conditions various phosphine oxides could be selectively reduced and the desired phosphines were usually obtained in excellent yields above 90%. Furthermore, we have developed a one-pot reaction sequence for the preparation of valuable phosphinborane adducts. Simple addition of BH3THF subsequent to the reduction step gave the desired adducts in yields up to 99%.
- Schirmer, Marie-Luis,Jopp, Stefan,Holz, Jens,Spannenberg, Anke,Werner, Thomas
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supporting information
p. 26 - 29
(2016/01/25)
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- Reversible Silylene Insertion Reactions into Si?H and P?H σ-Bonds at Room Temperature
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Phosphine-stabilized silylenes react with silanes and a phosphine by silylene insertion into E?H σ-bonds (E=Si,P) at room temperature to give the corresponding silanes. Of special interest, the process occurs reversibly at room temperature. These results demonstrate that both the oxidative addition (typical reaction for transient silylenes) and the reductive elimination processes can proceed at the silicon center under mild reaction conditions. DFT calculations provide insight into the importance of the coordination of the silicon center to achieve the reductive elimination step.
- Rodriguez, Ricardo,Contie, Yohan,Nougué, Raphael,Baceiredo, Antoine,Saffon-Merceron, Nathalie,Sotiropoulos, Jean-Marc,Kato, Tsuyoshi
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supporting information
p. 14355 - 14358
(2016/11/11)
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- Highly efficient reduction of tertiary phosphine oxides and sulfides with amine-assisted aluminum hydrides under mild conditions
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Reduction of tertiary phosphine oxides and sulfides into the corresponding phosphines with amine-assisted aluminum hydrides has been studied. The method is characterized by mild conditions, short reaction time, high efficiency, and expanded substrate scope. The new method is an alternative to the currently used methods of reducing phosphine oxides or recycling phosphines engaged in organic reactions.
- Yang, Shuyan,Han, Xinxin,Luo, Minmin,Gao, Jing,Chu, Wenxiang,Ding, Yuqiang
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p. 1156 - 1160
(2015/06/30)
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- α-Phosphanyl amino acids: Synthesis, structure and properties of alkyl and heterocyclic N-substituted diphenylphosphanylglycines Dedicated to Professor Dr. Dr. h.c. Manfred Scheer on the occasion of his 60th birthday
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N-Alkyl and N-heterocyclic substituted diphenylphosphanylglycines 1a-j were synthesized by a convenient one-pot, three-component reaction of diphenylphosphane, the corresponding primary amine and glyoxylic acid hydrate in diethyl ether. Phosphanylglycolates 2 and phosphoniobis(glycolates) 3 were detected as intermediates. In the case of steric hindrance or low basicity of the amine only 2 or mixtures of 2 and 1 are formed. Reactivity studies of selected phosphanylglycines showed facile decarboxylation and hydrolysis, oxidation and formation of coordination compounds with BH3 or W(CO)5. N-Alkyl derivatives (tert-butyl, n-hexyl, benzhydryl) with moderate steric hindrance reacted with Ni(COD)2 in THF or toluene in the presence of ethylene with heating under pressure to yield highly active oligomerization catalysts, and converting the ethylene to liquid and low-molecular-weight solid ethylene oligomers (MNMR 500-1250 g/mol) with high selectivity for linear α-olefins. Smaller N-alkyl or N-heterocyclic amino substituents at the phosphanyl acetic skeleton interfere with the ethylene conversion and deactivate the catalyst. The structures of the compounds were elucidated by solution NMR and single crystal XRD studies.
- Lach, Joanna,Peulecke, Normen,Kindermann, Markus K.,Palm, Gottfried J.,K?ckerling, Martin,Heinicke, Joachim W.
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p. 4933 - 4945
(2015/06/23)
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- Synthesis and Reactivity of Tris(Hydroxymethyl)Phosphine-Mimicking Nonsymmetrical Diphosphine Ligands
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As part of a study to obtain well-defined tris(hydroxymethyl)phosphine (THP)-inspired ligands, a new nonsymmetrical diphosphine featuring two hydroxymethyl functional groups on one phosphine terminus has been synthesized. A double formylation reaction was employed to effect the hydroxymethylation of the primary phosphine function in Ph2P(CH2)2PH2 and furnish the target bis(hydroxymethyl)phosphanylethyldiphenylphosphine. Initially, this methodology afforded complex product mixtures whose composition varied according to the reaction solvent, and these are assumed to result from acetalization of excess formaldehyde by the hydroxymethyl groups of the anticipated phosphine. The desired target could be obtained via a borane protection - deprotection pathway or by repeatedly treating the product mixture with H2O, thereby probably shifting a hemiacetal equilibrium of the phosphine with formaldehyde towards the free hydroxymethyl functionalities.
- Nijland, Aike,Van Zutphen, Steven,Carmichael, Duncan
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p. 720 - 724
(2016/01/15)
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- Synthesis and unexpected reactivity of [Ru(η 6-cymene)Cl2(PPh2Cl)], leading to [Ru(η 6-cymene)Cl2(PPh2H)] and [Ru(η 6-cymene)Cl 2 (PPh2OH)] complexes
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The reaction of [Ru(η 6-cymene)Cl2]2 and PPh2Cl in the ratio 1:2 gives a stable [Ru(η 6-cymene) Cl2(PPh2Cl)] complex. Attempts to make the cationic [Ru(η 6-cymene)Cl(PPh2Cl)2]Cl with excess PPh2Cl and higher temperatures led to adventitious hydrolysis and formation of [Ru(η 6-cymene)Cl2(PPh2OH)]. Attempts to make a phosphinite complex by reacting [Ru(η 6-cymene)Cl2]2 with PPh2Cl in the presence of an alcohol results in the reduction of PPh2Cl to give [Ru(η 6-cymene)Cl2(PPh2H)] and the expected phosphinite. The yield of the hydride complex is highest when the alcohol is 1-phenyl-ethane-1,2-diol. All three half-sandwich complexes are characterized by X-ray crystallography. Surprisingly, the conversion of chlorodiphenylphosphine to diphenylphosphine is mediated by 1-phenyl-ethane-1,2-diol even in the absence of the ruthenium half-sandwich precursor. [Figure not available: see fulltext.]
- Pandiakumar, Arun Kumar,Samuelson, Ashoka G
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p. 1329 - 1338
(2015/11/09)
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- Calcium-mediated hydrophosphorylation of organic isocyanates with diphenylphosphane oxide
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The calcium-mediated addition of diphenylphosphane oxide to organic isocyanates and isothiocyanates yields N-alkyl and N-aryl substituted diphenylphosphorylformamides (E≤O, R≤iPr, tBu, cHex, Ph, C6H4-4-Br, C6H2-2,4,6-Me3, and Naph) and -thioformamides (E≤S, R≤iPr, cHex, Ph, and C6H4-4-Me), respectively, of the type Ph2P(O)-C(E)-N(H)R. All derivatives were characterized by IR and NMR spectroscopy as well as X-ray diffraction experiments. The wavenumbers of the N-H stretching modes are smaller for the thio analogues and N-aryl substituents. In the solid state all formamides and thioformamides form dimers by N-HO-P hydrogen bridges. The P-CCE bonds are significantly elongated compared with the P-CPh distances.
- Haerling, Stephan,Greiser, Julia,Al-Shboul, Tareq M. A.,Goerls, Helmar,Krieck, Sven,Westerhausen, Matthias
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p. 1264 - 1273
(2013/10/22)
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- Frustrated lewis pair route to hydrodesilylation of silylphosphines
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A 1:1 mixture of P(SiMe3)3 and B(p-C 6F4H)3 reacts with 3 equiv of 4-heptanone to afford a 1:2 mixture of [(Me3SiO)(n-Pr)2C]H 2P-B(p-C6F4H)3 and the silyl enol ether, 4-trimethylsiloxy-3-heptene. Subsequent thermolysis of the adduct produces H3P-B(p-C6F4H)3 and an additional equiv of silyl enol ether. In the presence of a catalytic quantity of B(p-C6F4H)3, however, P(SiMe3) 3 reacts with 4-heptanone to produce a 1:1 mixture of [(Me 3SiO)(n-Pr)2C]2PH and silyl enol ether. Heating this mixture further produces [(Me3SiO)(n-Pr)2C]PH 2, which is eventually converted to elemental phosphorus.
- Takeuchi, Katsuhiko,Hounjet, Lindsay J.,Stephan, Douglas W.
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p. 4469 - 4472
(2013/09/23)
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- Investigation of the reductive cleavage of BINAP and application to the rapid synthesis of phospholes
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A rapid and easy entry into λ3-phospholes and λ4-phosphole oxides derived from BINAP is reported herein featuring a variety of C and Si substituents and functional groups, as well the investigative work on the mechanistic pathway. DFT calculations using B3LYP functionals have been carried out to rationalize the mechanism. The observed experimental 31P resonance shifts were compared with the calculated shifts of the proposed intermediates after calibration of the shielding tensors. The calculations included the use of polarizable continuum models to take into account solvent effects and were found to be in excellent agreement, providing further evidence for the proposed mechanism.
- Gallop, Chris W.D.,Bobin, Mariusz,Hourani, Petra,Dwyer, Jessica,Roe, S. Mark,Viseux, Eddy M. E.
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p. 6522 - 6528
(2013/07/26)
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- The reactivity of arylphosphorus acid amides under Birch reduction conditions
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Several classes of arylphosphorus acid amides have been tested in reactions with alkali metal solutions in liquid ammonia. The outcomes of such reactions depend on the structures of the starting materials. Generally, two processes-Birch reduction or cleavage of the P-aryl bond-can be operative. Diarylphosphinic amides tend to undergo double Birch reduction to afford bis(cyclohexadienyl)phosphinic amides. Copyright
- Stankevic, Marek,Wlodarczyk, Adam,Nieckarz, Damian
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p. 4351 - 4371
(2013/07/26)
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- Reduction of phosphine oxides to phosphines with the InBr3/TMDS system
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An efficient method for the reduction of phosphine oxide derivatives into their corresponding phosphines is described. The system InBr3/TMDS allows the reduction of different secondary and tertiary phosphine oxides as well as aliphatic and aromatic phosphine oxides.
- Pehlivan, Leyla,Métay, Estelle,Delbrayelle, Dominique,Mignani, Gérard,Lemaire, Marc
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supporting information; experimental part
p. 3151 - 3155
(2012/05/31)
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- General and selective copper-catalyzed reduction of tertiary and secondary phosphine oxides: Convenient synthesis of phosphines
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Novel catalytic reductions of tertiary and secondary phosphine oxides to phosphines have been developed. Using tetramethyldisiloxane (TMDS) as a mild reducing agent in the presence of copper complexes, PO bonds are selectively reduced in the presence of other reducible functional groups (FGs) such as ketones, esters, and olefins. Based on this transformation, an efficient one pot reduction/phosphination domino sequence allows for the synthesis of a variety of functionalized aromatic and aliphatic phosphines in good yields.
- Li, Yuehui,Das, Shoubhik,Zhou, Shaolin,Junge, Kathrin,Beller, Matthias
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supporting information; experimental part
p. 9727 - 9732
(2012/07/14)
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- Phosphonium bis(glycolates) and phosphinoglycolates: Synthesis, solvolysis, oxidation to (thio)phosphinoylglycolates and use as ligands in Ni-catalyzed ethylene oligomerization
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Secondary phosphines, glyoxylic acid hydrate and amines react to form organoammonium phosphonium bis(glycolates) 1a-d. In CD3OD solution, diphenylphosphonium bis(glycolates) undergo reversible solvolysis to phosphinoglycolates 2a,b and acetalic glyoxylic species. The P-dialkyl species 1c avoids this and maintains the phosphonium bis(glycolate) structure in CD 3OD (cHex2P) or undergoes further solvolysis with partial formation of R2PH (R = tBu). Condensation to phosphinoglycines, e.g. 3b, observed for primary amines, does not take place with N-secondary amines at room temperature. Heating leads to condensation but is followed by decarboxylation as shown for the conversion of 2a to 4a. Because of the kinetic lability, the phosphonium compounds 1a-d are sensitive to oxidation by air, H2O2, or sulfur. The resulting phosphinoyl and thiophosphinoyl glycolates and glycolic acids 5-8 are kinetically stable. Precatalyst solutions formed from 1a, c, d and Ni(COD)2 in THF developed moderate to good activity in the oligo- or polymerization of ethylene to linear products containing methyl and vinyl end groups. Activity and molecular weights increased with the +I-effect of the P-substitutents. The solution structures of the novel compounds were elucidated by multinuclear NMR spectroscopy. For 7a a crystal structure analysis is also presented.
- Peulecke, Normen,Kindermann, Markus K.,K?ckerling, Martin,Heinicke, Joachim
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body text
p. 61 - 69
(2012/08/27)
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- Electroreduction of triphenylphosphine oxide to triphenylphosphine in the presence of chlorotrimethylsilane
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Electroreduction of triphenylphosphine oxide to triphenylphosphine in an acetonitrile solution of tetrabutylammonium bromide in the presence of chlorotrimethylsilane was performed successfully in an undivided cell fitted with a zinc anode and a platinum cathode under constant current. A plausible mechanism involving, (1) one-electron reduction of triphenylphosphine oxide generating the corresponding anion radical [Ph3P-O-], (2) subsequent reaction with chlorotrimethylsilane affording the (trimethylsiloxy)triphenylphosphorus radical [Ph3P-OSiMe 3], and (3) further one-electron reduction followed by P-O bond fission leading to triphenylphosphine is proposed. In a similar manner, electroreduction of some triarylphosphine oxides and alkyldiarylphosphine oxides was executed to give the corresponding phosphine derivatives in good to moderate yields. Georg Thieme Verlag Stuttgart · New York.
- Kawakubo, Hiromu,Kuroboshi, Manabu,Yano, Tomotake,Kobayashi, Kazuma,Kamenoue, Syogo,Akagi, Tomomi,Tanaka, Hideo
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experimental part
p. 4091 - 4098
(2012/01/12)
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- A straightforward synthesis of unsymmetrical secondary phosphine boranes
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A one-pot procedure for the synthesis of unsymmetrical alkyl-substituted secondary phosphine oxides is described. The sequential addition of N-benzylaniline to a solution of dichlorophenylphosphine and 1-methylimidazole in methylcyclohexane, separating of the protic ionic liquid formed, addition of Grignard reagent followed by hydrolysis gave unsymmetrical secondary phosphine oxides (SPOs) in high yield. The use of ionic liquids in the first step is essential and streamlined the synthesis. Unsymmetrical SPOs could be quantitatively reduced to secondary phosphine using a catalytic amount of Ti(OiPr)4 and tetramethyldisiloxane (TMDS) under mild reaction conditions.
- Petit, Christelle,Favre-Reguillon, Alain,Mignani, Gerard,Lemaire, Marc
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experimental part
p. 326 - 330
(2011/03/18)
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- Reactions of amine-and phosphane-borane adducts with frustrated Lewis pair combinations of Group 14 triflates and sterically hindered nitrogen bases
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The ability of trialkyl Group 14 triflates in combination with amine and pyridine bases to dehydrogenate amine-and phosphane-borane adducts has been investigated. By using multinuclear NMR spectroscopy, it has been shown that Me2NH ·BH3 (11) is efficiently converted to [Me2N-BH2]2 (12) by the so-called "frustrated Lewis pair" (FLP) of nBu3SnOTf (4, -OTf = -OSO2CF3) and 2,2,6,6-tetramethylpiperidine (6). Within the scope of the study, exchange of the Lewis acid effects the rate of dehydrogenation in the order: 4 gt; Me3Si-OTf (2) gt; Et 3SiOTf (3). Exchange of the Lewis base for 2,6-di-tert-butylpyridine (5) has also been shown to reduce the rate of reaction, whereas 1,3-di-tert-butylimidazol-2-ylidene (7) reacted directly with 2 to afford 1,3-bis-tert-butyl-4-(trimethylsilyl)imidazolium triflate (8[OTf]). For FLP combinations for which dehydrogenation reaction times are longer, detectable quantities of [H2B(μ-H)(μ-NMe2)BH2] (14) are observed. Both the dehydrogenation reaction and competitive formation of this product are proposed to proceed by initial hydride abstraction by the Lewis acid, followed by deprotonation by the Lewis base, or combination with further dimethylamine-borane and elimination of [Me2NH2]OTf (18[OTf]), respectively. In contrast to 11, MeNH2·BH 3 (22) was not found to cleanly dehydrogenate to either [MeNH-BH 2]3 or [MeN-BH]3 under the same conditions. An alternative reaction pathway was observed with either 2 or 4 and 6 with Ph 2PH ·BH3 (23), resulting in P-silylation or P-stannylation of the phosphane-borane, respectively.
- Whittell, George R.,Balmond, Edward I.,Robertson, Alasdair P. M.,Patra, Sanjib K.,Haddow, Mairi F.,Manners, Ian
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experimental part
p. 3967 - 3975
(2011/01/11)
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- Calcium-centred phosphine oxide reactivity: P-C metathesis, reduction and P-P coupling
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Reactions of triphenylphosphine oxide and diphenylphosphine oxide with calcium alkyls and amides in the presence of PhSiH3 occur to give P-C bond cleavage, P(v) to P(iii) reduction and P-P coupling. The Royal Society of Chemistry.
- Hill, Michael S.,Mahon, Mary F.,Robinson, Thomas P.
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supporting information; experimental part
p. 2498 - 2500
(2010/08/13)
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- Bis-3-oxo-λ5-phosphole: Isolation, structural analyses, and synthesis of phosphorus-ylide containing conjugated heterocycle
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Figure presented A new class of phosphorus-ylide containing conjugate heterocycle was isolated from a mixture of colored products of the reaction of a silylphosphine and dimethyl acetylenedicarboxylate. The structure was determined and the selective synthesis was developed. The indigo-like bis-phosphole structure appears a green to blue color, which is derived from the low energy-gap of the phosphole.
- Nishimura, Yasunobu,Kawamura, Yuka,Watanabe, Yutaka,Hayashi, Minoru
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supporting information; experimental part
p. 3875 - 3877
(2010/08/06)
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- PROCESS FOR THE CARBONYLATION OF ETHYLENICALLY UNSATURATED COMPOUNDS, NOVEL CARBONYLATION LIGANDS AND CATALYST SYSTEMS INCORPORATING SUCH LIGANDS
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A novel bidentate catalytic ligand of general formula (I) is described. R represents a hydrocarbyl aromatic structure having at least one aromatic ring to which Q 1 and Q 2 are each linked, via the respective linking group, if present, on available adjacent atoms of the at least one aromatic ring. The groups X 3 and X 4 represent radicals joined via tertiary carbon atoms to the respective atom Q 1 and the groups X 1 and X 2 represent radicals joined via primary, or substituted aromatic ring carbon atom(s) to the respective atom Q 2. A and B represent an optional lower alkylene linking group. Q 1 and Q 2 each represent phosphorus, arsenic or antimony. A process for the carbonylation of ethylenically unsaturated compounds comprising reacting the compound with carbon monoxide in the presence of a source of hydroxyl groups, optionally, a source of anions and catalyst system obtainable by combining a metal of Group 8, 9 or 10 or a compound thereof and the bidentate ligand of general formula (I) is also described.
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Page/Page column 52-53
(2010/04/03)
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- Catalyst-free alcoholysis of phosphane-boranes: a smooth, cheap, and efficient deprotection procedure
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Catalyst-free alcoholytic deprotection of borane-protected phosphorus compounds offers a smooth, efficient, and clean alternative to existing deprotection methods. In this paper we report our results on the general applicability of deprotecting phosphane-
- Van Overschelde, Michel,Vervecken, Elias,Modha, Sachin G.,Cogen, Simon,Van der Eycken, Erik,Van der Eycken, Johan
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experimental part
p. 6410 - 6415
(2009/12/09)
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- Reduction of phosphinites, phosphinates, and related species with DIBAL-H
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Diisobutylaluminium hydride has been found to be an excellent reducing agent for phosphinites, phosphinates, and chlorophosphines. By performing reductions in situ, direct synthesis of secondary phosphine boranes from Grignard reagents has been achieved without isolation or purification of any intermediates. Georg Thieme Verlag Stuttgart.
- Busacca, Carl A.,Bartholomeyzik, Teresa,Cheekoori, Sreedhar,Raju, Ravinder,Eriksson, Magnus,Kapadia, Suresh,Saha, Anjan,Zeng, Xingzhong,Senanayake, Chris H.
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scheme or table
p. 287 - 291
(2009/07/01)
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