- Palladium/Xiao-Phos-Catalyzed Kinetic Resolution of sec-Phosphine Oxides by P-Benzylation
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P-stereogenic tert- and sec-phosphines have wide applications in asymmetric catalysis, materials, and pharmaceutical chemistry, however, their practical synthesis still constitutes a significant challenge. Herein, a successful kinetic resolution of rac-se
- Dai, Qiang,Liu, Lu,Zhang, Junliang
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supporting information
p. 27247 - 27252
(2021/11/17)
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- Scalable Enantiomeric Separation of Dialkyl-Arylphosphine Oxides Based on Host–Guest Complexation with TADDOL-Derivatives, and their Recovery
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Several dialkyl-arylphosphine oxides were prepared, and the enantioseparation of the corresponding racemates was elaborated with host–guest complexation using TADDOL-derivatives. The crystallization conditions were optimized and two separate crystallization methods, one in organic solvent, and the other in water, were found to yield five examples of phosphine oxides with enantiomeric excess values higher than 94 %. A gram scale resolution was performed, and both enantiomers of the methyl-phenyl-propyl-phosphine oxide were separated with (R,R)- or (S,S)-spiro-TADDOL. The intermolecular interactions responsible for the enantiomeric recognition between the chiral host and guest molecules were investigated by single-crystal X-ray diffractional structural determinations. The similarities in the structural patterns of a few diastereomeric crystals were checked by powder X-ray diffraction, as well. Organic solvent nanofiltration (OSN) was used as a scalable technique for the decomposition of the corresponding phosphine oxide–spiro-TADDOL molecular complexes, and for the recovery of the phosphine oxide enantiomers and resolving agents.
- Bagi, Péter,Fogassy, Elemér,Herbay, Réka,Holczbauer, Tamás,Keglevich, Gy?rgy,Mátrav?lgyi, Béla,Madarász, János,Székely, Gy?rgy,Varga, Bence
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supporting information
(2020/03/23)
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- Enantiodivergent Formation of C-P Bonds: Synthesis of P-Chiral Phosphines and Methylphosphonate Oligonucleotides
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Phosphorus Incorporation (PI, abbreviated Π) reagents for the modular, scalable, and stereospecific synthesis of chiral phosphines and methylphosphonate nucleotides are reported. Synthesized from trans-limonene oxide, this reagent class displays an unexpected reactivity profile and enables access to chemical space distinct from that of the Phosphorus-Sulfur Incorporation reagents previously disclosed. Here, the adaptable phosphorus(V) scaffold enables sequential addition of carbon nucleophiles to produce a variety of enantiopure C-P building blocks. Addition of three carbon nucleophiles to Π, followed by stereospecific reduction, affords useful P-chiral phosphines; introduction instead of a single methyl group reveals the first stereospecific synthesis of methylphosphonate oligonucleotide precursors. While both Π enantiomers are available, only one isomer is required - the order of nucleophile addition controls the absolute stereochemistry of the final product through a unique enantiodivergent design.
- Baran, Phil S.,Eastgate, Martin D.,Knouse, Kyle W.,Padial, Natalia M.,Rivas-Bascón, Nazaret,Schmidt, Michael A.,Vantourout, Julien C.,Xu, Dongmin,Zheng, Bin
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- Stereoselectivity of Michael Addition of P(X)-H-Type Nucleophiles to Cyclohexen-1-ylphosphine Oxide: The Case of Base-Selective Transformation
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Michael addition of phosphorus nucleophiles to the unsymmetrically substituted tert-butyl(1,4-cyclohexadien-3-yl)phosphine oxide and its derivatives has been described. The addition proceeds with the formation of the mixture of two isomeric products with good yield and diastereoselectivity. The reaction of tert-butyl(cyclohexen-1-yl)methylphosphine oxide with phosphorus nucleophiles is base sensitive and might afford two epimers which differ at one chirality center. The absolute configuration of the products has been assigned on the basis of conformational and 1H NMR analysis, and the mechanism of the reaction has been discussed. The Michael addition of phosphorus nucleophiles is postulated to proceed with or without consecutive epimerization of two α-carbanions.
- Jaklińska, Magdalena,Cordier, Marie,Stankevi?, Marek
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p. 1378 - 1390
(2016/03/01)
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- Aryl group - A leaving group in arylphosphine oxides
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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
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p. 810 - 824
(2016/01/20)
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- Synthesis and properties of tert-butylphenylmethylene(chloro)phosphorane
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The synthesis and properties of tert-butylphenylmethylene(chloro)phosphorane were described. The prepared chlorophosphorane reacted with alcohols and phenol with the formation of the corresponding phosphonium salts. Its reaction with carbonyl compounds le
- Kolodyazhna,Grishkun,Sheiko,Kolodyazhna,Kolodyazhnyi
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p. 1639 - 1643
(2015/08/25)
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- Room temperature, palladium-mediated P-arylation of secondary phosphine oxides
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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.
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supporting information
p. 4370 - 4373
(2012/10/29)
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- Reduction of tertiary phosphine oxides with DIBAL-H
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(Chemical Equation Presented) The reduction of tertiary phosphine oxides (TPOs) and sulfides with diisobutylaluminum hydride (DIBAL-II) has been studied in detail. An extensive solvent screen has revealed that hindered aliphatic ethers, such as MTBE, are optimum for this reaction at ambient temperature. Many TPOs undergo considerable reduction at ambient temperature and then stall due to inhibition. 31P and 13C NMR studies using isotopically labeled substrates as well as competition studies have revealed that the source of this inhibition is tetraisobutyldialuminoxane (TIBAO), which builds up as the reaction proceeds. TIBAO selectively coordinates the TPO starting material, preventing further reduction. Several strategies have been found to circumvent this inhibition and obtain full conversion with this extremely inexpensive reducing agent for the first time. Practical reduction protocols for these critical targets have been developed.
- Busacca, Carl A.,Raju, Ravinder,Grinberg, Nelu,Haddad, Nizar,James-Jones, Paul,Lee, Heewon,Lorenz, Jon C.,Saha, Anjan,Senanayake, Chris H.
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p. 1524 - 1531
(2008/04/12)
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- Synthesis of P-stereogenic phosphorus compounds. Asymmetric oxidation of phosphines under appel conditions
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Racemic phosphines are converted into enantioenriched phosphine oxides via a synthetically simple, but theoretically interesting, oxidation procedure in good enantiomeric excess (up to 80%) and excellent yields (>95%). These phosphine oxides can be oxidatively coupled to provide easy access to enantiopure DiPAMPO analogues. Particularly attractive aspects of this procedure are the operational simplicity and the low cost required to synthesize these high value compounds. Copyright
- Bergin, Enda,O'Connor, Cormac T.,Robinson, Shane B.,McGarrigle, Eoghan M.,O'Mahony, Colm P.,Gilheany, Declan G.
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p. 9566 - 9567
(2008/02/13)
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- CHIRAL PHOSPHORUS COMPOUNDS
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A process for the stereoselective preparation of a P-chiral four-co-ordinated phosphorus compound, the process comprising reacting a first reactant selected from the group consisting of a chiral alcohol, chiral amine or chiral thiol, with a second reactan
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Page/Page column 23; 31
(2010/02/15)
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- Enantiomerically pure disulfides: Key compounds in the kinetic resolution of chiral PIII-derivatives with stereogenic phosphorus
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Enantiomerically pure disulfides were reacted with various chiral P III-derivatives with stereogenic phosphorus such as tertiary phosphines, halogenophosphines, phosphinite and phosphole under kinetic resolution conditions to afford enantiomeri
- Perlikowska, Wieslawa,Gouygou, Maryse,Mikolajczyk, Marian,Daran, Jean-Claude
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p. 3519 - 3529
(2007/10/03)
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- Alkylation of phosphine boranes by phase-transfer catalysis
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(Matrix presented) The alkylation of phosphine boranes with various electrophiles proceeds with good to excellent yields in a biphasic solution in the presence of tetrabutylammonium bromide as a phase-transfer catalyst.
- Lebel, Helene,Morin, Sebastien,Paquet, Valerie
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p. 2347 - 2349
(2007/10/03)
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- Lewis acid catalyzed room-temperature Michaelis-Arbuzov rearrangement
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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
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p. 2389 - 2392
(2007/10/03)
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- Lipase-catalyzed kinetic resolution of P-chiral phosphorus compounds: Enantiopreference of Pseudomonas lipase and Candida antarctica lipase
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Optically active 1-hydroxymethylalkylphenylphosphine oxides 1a-c were prepared by Pseudomonas fluorescens lipase (lipase AK) and Candida antarctica lipase (CAL)-catalyzed optical resolution. Lipase AK-catalyzed resolution of tert-butyl derivative 1c showed R-selectivity, whereas CAL preferred the S-enantiomer.
- Shioji, Kosei,Ueno, Yuichiro,Kurauchi, Yoshimitsu,Okuma, Kentaro
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p. 6569 - 6571
(2007/10/03)
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- Reaction of metallated tert-butyl(phenyl)phosphane oxide with electrophiles as a route to functionalized tertiary phosphane oxides: Alkylation reactions
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P-Chiral tertiary phosphane oxides have been prepared from each of the secondary phosphane oxides racemic 1, (S(p))-(-)-4 and (Rp)-(+)-tert-butylphenylphosphane oxide (5) by lithiation with LDA or nBuLi, or sodiation with sodium hydride, in THF, and then by treatment with a series of primary alkyl halides. Doubly P-chiral ditertiary bis(phosphane oxides) are also obtained from these metallated secondary phosphane oxides by treatment with electrophiles based on straight-chain, tartrate-derived, and bishalomethylarene dihalides. In general, the bis-phosphane oxides are obtained in good yields. However, when the α,ω-dihalide bears an embedded heteroatom (O or Si), yields are diminished. The enantiomeric purity of each of the products was assessed through admixture with (R(p))- and (S(p))-tert-butyl(phenyl)phosphanylthioic acids and measurement of the tert-butyl resonances in the 1H-NMR spectra. In all cases, the act of metallation of the enantiomerically pure secondary phosphane oxide followed by its alkylation is not accompanied by detectable racemization. This method for preparing P-chiral tertiary phosphane oxides is therefore more straightforward than those described previously.
- Haynes, Richard K.,Au-Yeung, Tin-Lok,Chan, Wai-Kuen,Lam, Wai-Lun,Li, Zhi-Yi,Yeung, Lam-Lung,Chan, Albert S. C.,Li, Pauline,Koen, Mark,Mitchell, Craig R.,Vonwiller, Simone C.
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p. 3205 - 3216
(2007/10/03)
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- Preparation of Enantiomerically Pure Tertiary Phosphine Oxides from, and Assay of Enantiomeric Purity with, (Rp)- and (Sp)-tert-Butylphenylphosphinothioic Acids
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A convenient multigram scale method has been developed for preparation of enantiomerically-pure (Rp)- and (Sp)-tertiary phosphine oxides including allyl- and but-2-enyl-tert-butylphenylphosphine oxides wherein (Rp)- and (S
- Haynes, Richard K.,Freeman, Richard N.,Mitchell, Craig R.,Vonwiller, Simone C.
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p. 2919 - 2921
(2007/10/02)
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- The influence of radical stability of organomagnesium halide reagents on the direction of addition to an α,β-unsaturated phosphoryl group
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The addition of Grignard reagents with increasing radical character to α,β-unsaturated phosphoryl groups was found to occur with a corresponding increase in the yield of the aromatic substitution products. Molecular modelling was used to determine that the radical character has a greater role in determining the degree of aromatic substitution than does steric parameters.
- Gatrone,Jonson
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p. 2743 - 2751
(2007/10/02)
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- Synthesis of Optically Active Phosphorus Compounds via Metal Phosphinites Generated by Reaction of Optically Active Selenophosphinates with Phenyllithium
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Sequential treatment of optically active Se-benzyl t-butylphenylselenophosphinate with PhLi and then with electrophiles such as alkyl halides elemental selenium gave optically active phosphorus compounds in good chemical and optical yields with a retention of configuration at phosphorus atom, together with benzyl phenyl selenide.
- Kawashima, Takayuki,Iwanaga, Hiroki,Okazaki, Renji
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p. 1531 - 1532
(2007/10/02)
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- THE WITTIG REARRANGEMENT OF CHIRAL PHOSPHINOTHIOATES INDUCED BY THE TIN LITHIUM TRANSMETALLATION
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The title reaction using optically active S-stannylmethyl phosphinothiaoates, followed by quenching with alkyl iodide affords mainly the corresponding (alkylthiomethyl)phosphine oxides with a retention of configuration.
- Kawashima, Takayuki,Kojima, Satoshi,Miyake, Takashi,Inamoto, Naoki
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p. 201 - 204
(2007/10/02)
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- A NEW METHOD FOR THE SYNTHESIS OF OPTICALLY PURE PHOSPHINE OXIDES
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Tertiary phosphine oxides have been prepared with high enantiomeric excesses via intermediate menthyl 2-phosphinylacetates.
- Imamoto, Tsuneo,Sato, Kazuhiko,Johnson, Carl R.
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p. 783 - 786
(2007/10/02)
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- A SIMPLE CHIRAL SHIFT REAGENT FOR MEASUREMENT OF ENANTIOMERIC EXCESSES OF PHOSPHINE OXIDES
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(R)-(-)-N-(3,5-dinitrobenzoyl)-α-phenylethylamine is a chiral shift reagent which allows ee measurements of various phosphine oxides.Good results were obtained for monophosphine oxides with asymmetric phosphorus centers as well as with an asymmetric carbon in α position of phosphorus.The reagent is also able differentiate the two enantiomers of racemic DIOP dioxide.
- Dunach, E.,Kagan, H. B.
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p. 2649 - 2652
(2007/10/02)
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- The Proton Magnetic Resonance Spectra of Chiral Phosphinate Esters. Chemical Shift Non-equivalence of Enantiomers induced by Optically Active Phosphinothioic Acids
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The 1H n.m.r. spectrum of racemic methyl methylphenylphosphinate recorded in CCl4 solution in the presence of 1 mol. equiv. of (+)-(R)-phenyl-t-butylphosphinothioic acid or (-)-(S)-methylphenylphosphinothioic acid contains well separated P-m
- Harger, Martin J. P.
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p. 1505 - 1511
(2007/10/02)
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