10172-89-1Relevant articles and documents
Cross-linked crystals of subtilisin: Versatile catalyst for organic synthesis
Wang, Yi-Fong,Yakovlevsky, Kirill,Zhang, Bailing,Margolin, Alexey L.
, p. 3488 - 3495 (1997)
Cross-linked enzyme crystals (CLECs) of subtilisin exhibit excellent activity in aqueous and various organic solvents. This catalyst is more stable than the native enzyme in both aqueous and mixed aqueous/organic solutions. Subtilisin-CLEC was shown to be a versatile catalyst. It was used for the syntheses of peptides and peptidomimetics, mild hydrolysis of amino acid and peptide amides, enantio- and regioselective reactions, and transesterifications.
Modular solid-phase synthesis, catalytic application and efficient recycling of supported phosphine-phosphite ligand libraries
Heutz, Frank J. L.,Kamer, Paul C. J.
, p. 2116 - 2123 (2016)
In spite of decades of research in the field of homogeneous asymmetric catalysis the discovery of new high performance catalysts still relies heavily on trial-and-error. There is still a lack of efficient combinatorial methods which enable the synthesis and screening of vast ligand libraries, especially for bidentate phosphorus ligands. Here we present a highly modular solid-phase synthetic approach which provides facile access to libraries of phosphine-phosphite ligands in quantitative yield requiring only minimal work-up. The obtained library of supported phosphine-phosphites was successfully applied in rhodium catalyzed asymmetric hydrogenation obtaining high enantioselectivities up to 98%. Also, these polymer supported ligands could be successfully recycled under batch conditions exhibiting only a small decline of activity and no loss of selectivity.
Use of Heterogeneous Asymmetric Hydrogenation for the Preparation of a Chiral Phosphinite and Its Application as a Ligand in Homogeneous Asymmetric Hydrogenation
Bakos, Jozsef,Toth, Imre,Marko, Laszlo
, p. 5427 - 5428 (1981)
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Huang,Niemann
, p. 475 (1951)
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Glaser et al.
, p. 355,359 (1976)
Asymmetrische Katalyse III. Synthese, spektroskopische Untersuchungen und katalytische Wirkung eines neuen chiralen Phosphanliganden
Tillack, Annegret,Michalik, Manfred,Fenske, Dieter,Goesmann, Helmut
, p. 95 - 100 (1993)
The reduction of 3,4-bis(dimenthylphosphino)maleic anhydride (2) with LiAlH4 yields a new optically-active P-ligand, the chiral γ-lactone 3.The structure of 3 was determined by 1H, 13C and 31P-NMR spectroscopy, and X-ray crystal structure analysis.This ligand is used as co-catalyst with BF4 in the catalytic hydrogenation of α-acetamidocinnamic acid and methyl α-acetamidocinnamate.Optical yields of up to 75percent were obtained with the ester.
A novel tea-bag methodology for enzymatic resolutions of α-amino acid derivatives in reverse micellar media
Bhalerao,Rao,Fadnavis
, p. 2109 - 2118 (1994)
A novel tea bag methodology for resolution of methyl esters of N-acetyl- α-amino acids in reverse micellar medium of bis(2-ethylhexyl) sulfosuccinate sodium salt (AOT) in isooctane-chloroform using immobilized enzymes or microbial cells is presented. The methodology effectively solves the problems of substrate solubility, product separation and surfactant recycling and provides products in high yields (80 to 90%) and excellent optical purities (% ee 97 to >99%).
P-chirogenic diphosphazanes with axially chiral substituents and their use in rh-catalyzed asymmetric hydrogenation
Moritz, Jan-Ole,Chakrabortty, Soumyadeep,Bernd H. Mu.ller,Spannenberg, Anke,Kamer, Paul C. J.
, p. 14537 - 14544 (2020)
A convenient synthesis of enantiopure P-chirogenic diphosphazanes incorporating bulky bisphenol and 1,1′-bi-2-naphtholderived substituents via the functionalization of a readily accessible enantiopure lithium phosphinoamide with chlorophosphoridites was developed. Since the product requires no subsequent deprotection, the protocol provides an easy, convenient synthesis of P-chirogenic ligands on the gram scale. The ligands were applied in the Rh-catalyzed asymmetric hydrogenation of benchmark substrates furnishing enantiomeric excess values up to 96%.
Correlation of X-Ray Crystal Structures of Chiral Bisphosphine-Rhodium Catalysts and the Absolute Configuration of the Products Resulted by Their Asymmetric Hydrogenations
Sakuraba, S.,Morimoto, T.,Achiwa, K.
, p. 597 - 600 (1991)
The chiral positioning array (P/M-chirality) of four phenyl rings in the rhodium-chiral bisphosphine catalyst has been revealed to play an important tole in determining the absolute configuration of the asymmetric hydrogenation product.
Immobilization of rhodium complexes with chiral cationic water soluble ligands on Nafion-H and other strongly acidic cation exchange resins
Toth, Imre,Hanson, Brian E.,Davis, Mark E.
, p. 109 - 117 (1990)
Rhodium complexes of the chiral cationic water soluble ligands, pentane>4+, pentane>4+ and (S,S)-2,4-bis-bis)-p
Enantioselective hydrogenation in the presence of the rhodium(I) complex with (+)-4S,5S-N4,N4,N5,N5,2,2-hexamethyl -1,3-dioxolane-4,5-dimethaneamine
Nindakova,Shainyan,Albanov
, p. 1860 - 1866 (2001)
Hydrogenation of α-acetamidocinnamic and itaconic acids and their esters was carried out in the presence of the cationic Rh1 triflate complex with (+)-4S,5S-N4,N4,N5,N5,2,2-hexamethyl -1,3-dioxolane-4,5-dimethaneamine (DIODMA). The optical yields depended on the nature of the solvent and the hydrogen pressure and reached 30%. The catalytically active forms of the complexes and their transformations in the presence of phosphines, molecular hydrogen, and the substrate were studied by 1H and 31P NMR spectroscopy.
Ruthenium (II)-sulfonated BINAP: A novel water-soluble asymmetric hydrogenation catalyst
Wan,Davis
, p. 2461 - 2468 (1993)
Ruthenium (II)-sulfonated-BINAP has been synthesized and this novel water-soluble complex is shown to be an excellent asymmetric hydrogenation catalyst for 2-acylamino acid precursors and methylenesuccinic acid in both methanolic as well as in neat water solvent systems. Enantiomeric excesses approaching 90% have been obtained in aqueous and methanolic solvents. Effects of solvent, pressure and the addition of organic base on enantioselectivity are described.
Enantiopure 1,2-Bis(tert-butylmethylphosphino)benzene as a highly efficient ligand in rhodium-catalyzed asymmetric hydrogenation
Tamura, Ken,Sugiya, Masashi,Yoshida, Kazuhiro,Yanagisawa, Akira,Imamoto, Tsuneo
, p. 4400 - 4403 (2010)
Figure Presented. An electron-rich P-stereogenic bisphosphine ligand named "BenzP" was conveniently prepared from o-dibromobenzene and enantiopure tert-butylmethylphosphine-borane. Its rhodium complex exhibited excellent enantioselectivities of up to 99.9% and high catalytic activity of up to 10000 h-1 TOF in asymmetric hydrogenations of various functionalized alkenes.
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Overby,Ingersoll
, p. 3363,3364, 3365 (1951)
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Ionic liquid-phase asymmetric catalytic hydrogenation: Hydrogen concentration effects on enantioselectivity
Berger, Alexsandro,De Souza, Roberto F.,Delgado, Marcelo R.,Dupont, Jairton
, p. 1825 - 1828 (2001)
Molecular hydrogen is almost four times more soluble in the ionic liquid 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMI·BF4) than in its hexafluorophosphate (BMI·PF6) analogue at the same pressure. The Henry coefficient solubility constant for the solution BMI·BF4/H2 is K = 3.0 × 10-3 mol L-1 atm-1 and 8.8 × 10-4 mol L-1 atm-1 for BMI·PF6/H2, at room temperature. The asymmetric hydrogenation of (Z)-α-acetamido cinnamic acid and kinetic resolution of (±)-methyl-3-hydroxy-2-methylenebutanoate by (-)-1,2-bis((2R,5R)-2,5-diethylphospholano)benzene(cyclooctadiene)rhodium(I) trifluoromethanesulfonate and ichloro[(S)-(-)-2,2′-bis(di-p-tolylphosphino)-1,1′- binaphthyl]ruthenium(II) complexes immobilised in BMI·PF6 and BMI·BF4 were investigated. Remarkable effects in the conversion and enantioselectivity of these reactions were observed as a function of molecular hydrogen concentration in the ionic phase rather than pressure in the gas phase.
Application of chiral mixed phosphorus/sulfur ligands to enantioselective rhodium-catalyzed dehydroamino acid hydrogenation and ketone hydrosilylation processes
Evans, David A.,Michael, Forrest E.,Tedrow, Jason S.,Campos, Kevin R.
, p. 3534 - 3543 (2003)
Chiral mixed phosphorus/sulfur ligands 1-3 have been shown to be effective in enantioselective Rh-catalyzed dehydroamino acid hydrogenation and ketone hydrosilylation reactions (eqs 1, 2). After assaying the influence of the substituents at sulfur, the substituents on the ligand backbone, the relative stereochemistry within the ligand backbone, and the substituents at phosphorus, ligands 2c (R = 3,5-dimethylphenyl) and 3 were found to be optimal in the Rh-catalyzed hydrogenation of a variety of α-acylaminoacrylates in high enantioselectivity (89-97% ee). A similar optimization of the catalyst for the Rh-catalyzed hydrosilylation of ketones showed that ligand 3 afforded the highest enantioselectivities for a wide variety of aryl alkyl and dialkyl ketones (up to 99% ee). A model for asymmetric induction in the hydrogenation reaction is discussed in the context of existing models, based on the absolute stereochemistry of the products and the X-ray crystal structures of catalyst precursors and intermediates.
Chiral bicyclic O,N-bis(diphenylphosphino)aminoalkanols as ligands for enantioselective metal complex hydrogenation catalysts
Doebler, Chr.,Kreuzfeld, H.-J.,Pracejus, H.
, p. 89 - 92 (1988)
The enantiomers of O,N-bis(diphenylphosphino)-2-exo-hydroxy,3-endo-methylamino-norbornene have been prepared from the corresponding aminoalcohols and Ph2PCl.These compounds have been used as ligand for Rh complexes and tested in asymmetric hydrogenation of α-acetamidocinnamic acid, methyl-α-acetamidocinnamate and acetamodoacrylic acid.Optical yields of up to 90percent were obtained.
Complementary Diastereoselectivity in the Synthesis and Hydrolysis of Acylated Cyclodextrins
Coates, John H.,Easton, Christopher J.,Fryer, Nicholas L.,Lincoln, Stephen F.
, p. 1153 - 1156 (1994)
The diastereoselectivity of acylation of β-cyclodextrin with the acid chlorides of Ibuprofen, Flurbiprofen and 2-phenylpropanoic acid is complementary, in absolute and relative terms, to that observed in the hydrolysis of the corresponding cyclodextrin esters.
Amphiphilic polymer supports for the asymmetric hydrogenation of amino acid precursors in water
Zarka, M. Tobias,Nuyken, Oskar,Weberskirch, Ralf
, p. 3228 - 3234 (2003)
This paper describes the synthesis and characterization of a new class of amphiphilic, water-soluble diblock copolymers based on 2-oxazoline derivatives with pendent (2S,4S)-4-diphenylphosphino-2-(diphenylphosphinomethyl)pyrrolidine (PPM) units in the hydrophobic block. The synthetic strategy involves the preparation of a diblock copolymer precursor with ester functionalities in the side chain; which were converted into carboxylic acids in a polymer-analogous step and finally reacted with the PPM ligand. The structures of the copolymers were characterized by 1H and 31P NMR spectroscopy and GPC measurements. Subsequently, these polymers were successfully utilized as a polymeric support for the asymmetric hydrogenation of 1) (Z)-α-acetamido cinnamic acid and 2) methyl (Z)-α-acetamido cinnamate in water, showing 90% substrate conversion at 25 °C within 20 minutes at atmospheric H2 pressure (1 bar) for methyl (Z)-α-acetamido cinnamate.
Bipnor: A new, efficient bisphosphine having two chiral, nonracemizable, bridgehead phosphorus centers for use in asymmetric catalysis
Robin, Frederic,Mercier, Francois,Ricard, Louis,Mathey, Francois,Spagnol, Michel
, p. 1365 - 1369 (1997)
Optically active phosphorus ligands are widely used in homogeneous asymmetric catalysis. However, among the numerous available structures of this type, the subclass of optically active bisphosphines with at least one chiral phosphorus atom is rather underdeveloped. A bisphosphine with two chiral, nonracemizable bridgehead phosphorus centers, (meso,d/l)-2,2',3,3'-tetraphenyl-4,4',5,5'-tetramethyl-6,6'-bis-1-phosphanorb orna-2,5-dienyl (BIPNOR), can be obtained by thermolysis of 1,1'-bisphospholyl with diphenylacetylene. Here, we report the resolution of the d/l isomer by means of a chiral palladium complex to give the two optically active forms of BIPNOR. We then investigate the catalytic properties of BIPNOR, incorporated in Rh(I) and Ru(II) catalysts for the hydrogenation of olefins and ketones and in a Pd(II) catalyst for asymmetric alkylation reactions. BIP-NOR is shown to give good results in these catalytic reactions.
Synthesis of Binol-based diphosphinites bearing chiral phospholane units and their application in asymmetric catalysis
Hammerer, Tim,Weisgerber, Laurent,Schenk, Stefan,Stelzer, Othmar,Englert, Ulli,Leitner, Walter,Franci, Giancarlo
, p. 53 - 59 (2012)
New diphosphinite ligands based on atropoisomeric diol backbones and (R,R)-2,5-dimethylphospholane moieties have been prepared and fully characterised. For each ligand structure, both diastereomers have been synthesised. These ligands are available through a straightforward procedure in good yields. The solid state structures of two diastereomeric ligands are reported. These ligands have been applied to Rh-catalysed asymmetric hydrogenations and hydroformylations of CC bonds as well as in Ir-catalysed asymmetric hydrogenations of CN bonds. Turnover frequencies in the range of 10,000 h-1 and enantioselectivities of up to 98% ee have been achieved. The different chirality elements within the ligands led to marked cooperative effect in catalysis. Interestingly, there is no general privileged diastereomeric structure but rather a matched diastereomer for each application.
Highly Enantioselective Pd-Catalyzed Synthesis of P-Stereogenic Supramolecular Phosphines, Self-Assembly, and Implication
Koshti, Vijay S.,Mote, Nilesh R.,Gonnade, Rajesh G.,Chikkali, Samir H.
, p. 4802 - 4805 (2015)
Metal-catalyzed asymmetric addition of a secondary phosphine to an aryl halide is one of the most efficient and reliable approaches for the construction of enantiopure carbon-phosphorus bonds. An isolated Pd(II) complex (5) catalyzes the carbon-phosphorus coupling reaction between tolylphenylphosphine (1a) and 3-iodophenylurea (2b), which proceeds with an unprecedented enantiomeric excess (ee) of 97%. The generality of the strategy has been demonstrated by preparing a small library of a new class of P-stereogenic phosphines with an in-built hydrogen bonding motif for the first time. The P-stereogenic phosphines self-assemble on a metal template via deliberately installed hydrogen-bonding motifs and mimic the bidentate ligand coordination. Interestingly, when it was employed in asymmetric hydrogenation, the supramolecular phosphine {1-(3-(phenyl(o-tolyl)phosphanyl)phenyl)urea} (6b) produced the corresponding hydrogenated product with the highest enantiomeric excess of 99% along with excellent conversion, demonstrating the potential of these enantioenriched P-chirogenic supramolecular phosphines in asymmetric catalysis.
A novel chiral water-soluble phosphine ligand based on a water-soluble acrylic acid salt
Malmstroem, Torsten,Andersson, Carlaxel
, p. 1135 - 1136 (1996)
(2S,4S)-4-diphenylphosphino-2-diphenylphosphinomethylpyrrolidine reacts with poly(acrylic acid) to form a macro-ligand useful in biphasic chiral reductions.
Modification of (S)-N,N-Dimethyl-1-ethylamine (BPPFA) as a Ligand for Asymmetric Hydrogenation of Olefins Catalyzed by a Chiral Rhodium (I) Complex
Yamamoto, Keiji,Wakatsuki, Junya,Sugimoto, Ryuichi
, p. 1132 - 1137 (1980)
Asymmetric homogeneous hydrogenation of prochiral olefins catalyzed by chiral rhodium (I) complexes was carried out by using several ferrocenylphosphines as ligands which play a key role of the chiral recognition.Modifications of BPPFA were made in order to examine a steric effect of the given substituent at the asymmetric center on the efficiency of the chiral ligands, indicating the parent BPPFA to be superior to the others examined for the asymmetric hydrogenation of highly functionalized olefins.
Selectivity in Carbonic Anhydrase Catalyzed Hydrolysis of Standard N-Acetyl-DL-amino Acid Methyl Esters
Chenevert, Robert,Rhlid, Rachid Bel,Letourneau, Martin,Gagnon, Rene,D'Astous, Linda
, p. 1137 - 1140 (1993)
Carbonic anhydrase-catalyzed hydrolysis of some standard N-acetyl-DL-amino acid methyl esters proceeds with high enantioselectivity.This enzyme hydrolyses selectively D amino acid derivatives in contrast to proteases which have a L stereoselectivity. Key Words: carbonic anhydrase, hydrolysis, N-acetyl-DL-amino acid methyl esters, enantioselectivity.
Structure-activity relationship studies of dipeptide-based hepsin inhibitors with Arg bioisosteres
Kwon, Hongmok,Ha, Hyunsoo,Jeon, Hayoung,Jang, Jaebong,Son, Sang-Hyun,Lee, Kiho,Park, Song-Kyu,Byun, Youngjoo
supporting information, (2020/12/25)
Hepsin is a type II transmembrane serine protease (TTSP) associated with cell proliferation and overexpressed in several types of cancer including prostate cancer (PCa). Because of its significant role in cancer progression and metastasis, hepsin is an attractive protein as a potential therapeutic and diagnostic biomarker for PCa. Based on the reported Leu-Arg dipeptide-based hepsin inhibitors, we performed structural modification and determined in vitro hepsin- and matriptase-inhibitory activities. Comprehensive structure-activity relationship studies identified that the p-guanidinophenylalanine-based dipeptide analog 22a exhibited a strong hepsin-inhibitory activity (Ki = 50.5 nM) and 22-fold hepsin selectivity over matriptase. Compound 22a could be a prototype molecule for structural optimization of dipeptide-based hepsin inhibitors.
Batch versus flow stereoselective hydrogenation of Α-acetamido-cinnamic acid catalyzed by an Au(I) complex
Negoi, Alina,Cojocaru, Bogdan,Parvulescu, Vasile I.,Imlyhen, Nora,Gouygou, Maryse
, (2019/05/28)
A chiral gold (I) (2S,4S)-1-tert-butoxycarbonyl-4-diphenylphosphino-2-(diphenylphosphino- methyl) pyrrolidine (BPPM) complex has been prepared using [Au(SMe2)Cl] as precursor. The heterogenization of the Au-BPPM catalyst onto the CNT support followed two routes, ie (i) the non-covalent immobilization of the gold(I)complex by dry-impregnation, and (b) covalent immobilization of the gold(I)complex on a pre-functionalized CNT. These catalysts afford the stereoselective hydrogenation of α-acetamidocinnamic acid to the (R)-N-acetyl-phenylalanine enantiomer. The nature of the solvent affected both the enantioselectivity and TOFs. Among MeOH, EtOH, and TFE, methanol appeared to be the most efficient one (at 80 °C a TOF of 0.37 h?1 for a total enantioselectivity to the R-isomer). Transferring the reaction in the flow reactor, under similar conditions (methanol, room temperature) led to a 10 time increase of the TOF with no change in the stereoselectivity. The decrease of the TOF in time for both the reference Rh and the Au catalysts was assigned to their partial modification under the reaction conditions. The heterogenization of the Au-BPPM catalyst onto the CNT support, for the same content of Au-complex, led to a very important increase of the conversion with no change in the selectivity. However, the covalent bonding was more efficient affording a very high increase of the conversion even at room temperature (95% after 24 h), thus demonstrating that the anchoring a support increases the dispersion, and in consequence the efficiency. These CNT-Au-BPPM catalysts preserved the catalytic performances during recycling as also confirmed by the characterization results.
