- Preparation method of chiral 1, 2-bis [(2-methoxyphenyl) phenylphosphino] ethane
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The invention discloses a preparation method of chiral 1, 2-bis [(2-methoxyphenyl) phenylphosphino] ethane, and belongs to the field of organic synthesis. According to the method, (2-methoxyphenyl) (phenyl) phosphine oxide chloride is used as an initial raw material; 2-methoxyphenyl) (phenyl) phosphine oxide lithium is prepared from 2-methoxyphenyl and metal lithium, then the 2-methoxyphenyl) (phenyl) phosphine oxide lithium reacts with 1, 2-dibromoethane to obtain racemic 1, 2-bis [(2-methoxyphenyl) phenylphosphine oxide] ethane, chiral 1, 2-bis [(2-methoxyphenyl) phenylphosphine oxide] ethane is obtained after chiral resolution, and finally trivalent chiral 1, 2-bis [(2-methoxyphenyl) phenylphosphine oxide] ethane is obtained through reduction. The invention relates to 1, 2-bis [(2-methoxyphenyl) phenylphosphino] ethane. Compared with the prior art, the method has the advantages of short reaction steps, simple operation and high yield, and is more suitable for industrial production. The prepared chiral 1, 2-bis [(2-methoxyphenyl) phenylphosphino] ethane is used as a ligand for chiral catalysis and is applied to the field of medicines.
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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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- Preparation method of chiral 1, 2-bis [(2-methoxyphenyl) phenylphosphino] ethane
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The invention discloses a preparation method of chiral 1, 2-bis [(2-methoxyphenyl) phenylphosphino] ethane, and belongs to the technical field of organic chemistry. The preparation method is carried out according to the following reaction path: the reacti
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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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- Unraveling the catalytic cycle of tertiary phosphine oxides reduction with hydrosiloxane and Ti(O i Pr)4 through EPR and 29Si NMR spectroscopy
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The reduction of tertiary phosphine oxides using tetramethyldisiloxane (TMDS) as a mild reducing agent and catalytic amount of TiIV isopropoxide has been studied in detail. An extensive EPR study has revealed the presence of at least five TiIII species, and structures have been proposed. Thus, a single electron transfer (SET) mechanism consisting of a back and forth oxido-reduction of Ti from the IV to the III oxidation state could be proposed. Reduction of TiIV produces a Si? that undergoes a O2- abstraction from PV compounds leading to PIII compounds and Si-O? species. Reoxidation of TiIII by the latter gives silanol species. This mechanism was further probed by 29Si NMR analysis of the reaction mixture as a function of time and by the reduction of optically active P-stereogenic tertiary phosphine oxides. A practical reduction protocol of Ph3PO with these environmentally benign reagents on a 100 g scale has been developed.
- Petit, Christelle,Poli, Evelyne,Favre-Reguillon, Alain,Khrouz, Lhoussain,Denis-Quanquin, Sandrine,Bonneviot, Laurent,Mignani, Gerard,Lemaire, Marc
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p. 1431 - 1438
(2013/07/26)
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- A convenient and mild chromatography-free method for the purification of the products of Wittig and Appel reactions
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A mild method for the facile removal of phosphine oxide from the crude products of Wittig and Appel reactions is described. Work-up with oxalyl chloride to generate insoluble chlorophosphonium salt (CPS) yields phosphorus-free products for a wide variety of these reactions. The CPS product can be further converted into phosphine.
- Byrne, Peter A.,Rajendran, Kamalraj V.,Muldoon, Jimmy,Gilheany, Declan G.
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supporting information; experimental part
p. 3531 - 3537
(2012/05/20)
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- Profiling the tuneable R-SMS-Phos structure in the rhodium(i)-catalyzed hydrogenation of olefins: The last stand?
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A diversified family of enantiopure P-stereogenic "R-SMS-Phos" {R-SMS-Phos = 1,2-bis[(o-RO-phenyl)(phenyl)phosphino]ethane} ligands wherein R = branched or heteroatom-substituted alkyl, aralkyl, silyl, acyl, sulfonyl, etc. was screened for the Rh(i)-catalyzed hydrogenation of a representative set of olefinic substrates. This systematic and detailed investigation revealed a marked beneficial impact on enantioselectivity and catalyst activity in comparison to Knowles' ultimate DiPAMP {DiPAMP = 1,2-bis[(o-anisyl)(phenyl) phosphino]ethane} design. Mutant ligands with highly enhanced properties possessing particular features wherein the DiPAMP structure is found embedded were identified. The Royal Society of Chemistry 2011.
- Stephan, Michel,?terk, Damjan,Zupan?i?, Borut,Mohar, Barbara
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supporting information; experimental part
p. 5266 - 5271
(2011/09/20)
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- Impact of incorporating substituents onto the P-o-anisyl groups of DiPAMP ligand on the rhodium(I)-catalyzed asymmetric hydrogenation of olefins
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The introduction of 1,2-bis[(o-anisyl)-(phenyl)phosphino]ethane (DiPAMP) as a P-stereogenic ligand for rhodium(I)-catalyzed hydrogenation by Knowles et al. came after their evaluation of several diphosphines. However, no in-depth study was carried out on incorporating various substituents on its P-o-anisyl groups. In this work, we have prepared a large series of enantiopure and closely related DiPAMP analogues possessing various substituents (MeO, TMS, t-Bu, Ph, fused benzene ring) on the o-anisyl rings. The new ligands were evaluated in rhodium-catalyzed hydrogenation of several model substrates: methyl α-acetamidoacrylate, methyl (Z)-α-acetamidocinnamate, methyl (Z)-β-acetamidocrotonate, dimethyl itaconate, and atropic acid. They displayed enhanced activities and increased enantioselectivities, particularly the P-(2,3,4,5-tetra-MeO-C6H)-substituted ligand (4MeBigFUS). Interestingly enough, 88% ee was obtained in the hydrogenation of atropic acid using the Rh-(4MeBigFUS) catalyst under mild conditions (10 bar H2, room temperature) versus 7% ee using Rh-DiPAMP. Conversely, the ligand possessing P-(2,6-di-MeO-C6H3) groups proved to slow down considerably the hydrogenation. X-Ray structures of their corresponding Rh complexes are presented and discussed.
- Zupancic, Borut,Mohar, Barbara,Stephan, Michel
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experimental part
p. 2024 - 2032
(2009/09/07)
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- Process for producing optically active benzhydrol compounds
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A process for producing a benzhydrol compound (II) which comprises hydrogenating a benzophenone compound (I) in the presence of a hydrogenation catalyst consisting of a transition metal complex, a base and an optically active diamine compound: STR1 wherein R1 to R10 each represents H, OH, C1-4 alkyl, C1-4 alkoxy, C1-4 alkanoyl, etc., R2 and R3, and R8 and R9 may form --CH=CH--CH=CH--, or any two of R1 to R9 adjacent to each other may be bonded to thereby form --OCH2 O-- or --(CH2)3 --. By using this process, optically active benzhydrol compounds which have a high purity and are useful as, for example, intermediates in the synthesis of drugs can be produced by simple procedures.
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- An Efficient Procedure for the Synthesis of Electron Rich Biphosphines Containing Homochiral Backbones.
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An eminently practical method for the synthesis of homochiral biphosphines is described.This procedure entails the sequential reaction of homochiral ditosylate with the appropriate dialkylphosphine-borane anion followed by BH3 decomplexation mediated by HBF4*OMe2.
- McKinstry, Lydia,Livinghouse, Tom
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p. 9319 - 9322
(2007/10/02)
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- A useful synthesis of (R,R)-1,2-ethanediylbis[(o-methoxyphenyl)phenylphosphine] the ligand of the enantioselective catalyst [Rh(COD) (DIPAMP)]+ BF4-
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1,2-Ethanediylbis[(o-methoxyphenyl)phenylphosphine] the ligand of the enantioselective catalyst [Rh(1,5-COD)(DIPAMP)]+ BF4- is prepared from (1S)-bornyl (R)p-methyl(phenyl)phosphinate, which is diastereoselectively formed.
- Schmidt,Riedl,Griesser,Fitz
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p. 655 - 657
(2007/10/02)
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- Asymmetric synthesis of phosphinates, phosphine oxides and phosphines by Michaelis Arbuzov rearrangement of chiral oxazaphospholidine
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A general approach to asymmetric synthesis of high optically active tertiary organophosphorus compounds is described.Oxazaphospholidine 3 reacts with alkyl halide to give regio and stereoselectively the corresponding phosphinamide 4.Methyl phenyl phosphin
- Juge, S.,Genet, J. P.
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p. 2783 - 2786
(2007/10/02)
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- Asymmetric catalysis
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New optically active bis phosphine compounds which are useful in optically active catalysts. Such catalysts are particularly useful in catalytic asymmetric hydrogenation.
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