10531-50-7Relevant articles and documents
NAD(P)+-NAD(P)H. 39. Asymmetric Reduction by 1,4-Dihydronicotinamide Derivative Bound to Protein
Ohno, Atsuyoshi,Ushida, Satoshi,Oka, Shinzaburo
, p. 564 - 567 (1983)
1,4-Dihydronicotinamide derivatives covalently bound to NH2 or SH group of proteins such as reduced keratin (RK), egg white albumin (EWA), and bovine serum albumin (BSA) have been synthesized and subjected to the reductions of α,α,α-trifluoroacetophenone
Monitoring surface processes during heterogeneous asymmetric hydrogenation of ketones on a chirally modified platinum catalyst by operando spectroscopy
Meemken, Fabian,Hungerbuehler, Konrad,Baiker, Alfons
, p. 8640 - 8644 (2014)
Surface processes occurring at the catalytic chiral surface of a cinchona-modified Pt catalyst during the asymmetric hydrogenation of activated ketones have been monitored for the first time using operando ATR-IR spectroscopy. Fundamental information about this catalytic system could be gained, including the chiral modification process of the catalyst, the surface interaction of reactant ketone with preadsorbed chiral modifier, the role of hydrogen as well as the influence of the product enantiomers in the catalytic cycle. The formation of a diastereomeric transient surface complex between ketone and chiral modifier was found to be related to the ketone consumption. Among the studied activated ketones, a correlation between stereoselection and the strength of the intermolecular hydrogen bond was identified. Dissociated hydrogen from the catalytic surface is found to play a crucial role in the formation of the diastereomeric surface complex.
Enantioselective reduction of trifluoromethyl ketones using an oxazaborolidine catalyst generated in situ from a chiral lactam alcohol
Kawanami, Yasuhiro,Hoshino, Katsuhiro,Tsunoi, Wataru
, p. 1464 - 1466 (2011)
The oxazaborolidine catalyst prepared in situ from the chiral lactam alcohol 2 and borane was found to catalyze the enantioselective reduction of highly reactive trifluoromethyl ketones at room temperature with high enantioselectivities of up to 86% ee.
Electrochemically Promoted Asymmetric Transfer Hydrogenation of 2,2,2-Trifluoroacetophenone
Wang, Huan,Yue, Ying-Na,Xiong, Rui,Liu, Yu-Ting,Yang, Li-Rong,Wang, Ying,Lu, Jia-Xing
, p. 16158 - 16161 (2021)
The study reported an electrochemically promoted asymmetric hydrogen transfer reaction of 2,2,2-trifluoroacetophenone with a chiral Ru complex. (R)-α-(Trifluoromethyl) benzyl alcohol with a 96% yield and 94% ee could be obtained with only a 0.5 F mol-1charge amount at room temperature and normal pressure.
Enantioselective hydrogenation of ketones by iridium nanoparticles ligated with chiral secondary phosphine oxides
Cano, Israel,Tschan, Mathieu J.-L.,Martínez-Prieto, Luis M.,Philippot, Karine,Chaudret, Bruno,Van Leeuwen, Piet W.N.M.
, p. 3758 - 3766 (2016)
Chiral iridium nanoparticles (IrNPs) were synthesized by H2 reduction of (1,5-cyclooctadiene)(methoxy)iridium(i) dimer ([Ir(OMe)(COD)]2) in the presence of an asymmetric secondary phosphine oxide (4,5-dihydro-3H-dinaphtho[2,1-c:1′,2′
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Knollmueller,M.,Noe,C.R.,Oberhauser,B.
, p. 407 (1986)
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Genetically programmed chiral organoborane synthesis
Jennifer Kan,Huang, Xiongyi,Gumulya, Yosephine,Chen, Kai,Arnold, Frances H.
, p. 132 - 136 (2017)
Recent advances in enzyme engineering and design have expanded nature's catalytic repertoire to functions that are new to biology1-3. However, only a subset of these engineered enzymes can function in living systems4-7. Finding enzymatic pathways that form chemical bonds that are not found in biology is particularly difficult in the cellular environment, as this depends on the discovery not only of new enzyme activities, but also of reagents that are both sufficiently reactive for the desired transformation and stable in vivo. Here we report the discovery, evolution and generalization of a fully genetically encoded platform for producing chiral organoboranes in bacteria. Escherichia coli cells harbouring wild-type cytochrome c from Rhodothermus marinus8 (Rma cyt c) were found to form carbon-boron bonds in the presence of borane-Lewis base complexes, through carbene insertion into boron-hydrogen bonds. Directed evolution of Rma cyt c in the bacterial catalyst provided access to 16 novel chiral organoboranes. The catalyst is suitable for gram-scale biosynthesis, providing up to 15,300 turnovers, a turnover frequency of 6,100 h-1, a 99:1 enantiomeric ratio and 100% chemoselectivity. The enantiopreference of the biocatalyst could also be tuned to provide either enantiomer of the organoborane products. Evolved in the context of whole-cell catalysts, the proteins were more active in the whole-cell system than in purified forms. This study establishes a DNA-encoded and readily engineered bacterial platform for borylation; engineering can be accomplished at a pace that rivals the development of chemical synthetic methods, with the ability to achieve turnovers that are two orders of magnitude (over 400-fold) greater than those of known chiral catalysts for the same class of transformation9-11. This tunable method for manipulating boron in cells could expand the scope of boron chemistry in living systems.
β-Hydroxyamide-based ligands and their use in the enantioselective borane reduction of prochiral ketones
Azizoglu, Murat,Erdogan, Asli,Arslan, Nevin,Turgut, Yilmaz
, p. 21 - 26 (2014)
Hydroxyamide-based ligands have occupied a considerable place in asymmetric synthesis. Here we report the synthesis of seven β-hydroxyamide-based ligands from the reaction of 2-hydroxynicotinic acid with chiral amino alcohols and test their effect on the enantioselective reduction of aromatic prochiral ketones with borane in tetrahydofuran (THF). They produce the corresponding secondary alcohols with up to 76% enantiomeric excess (ee) and good to excellent yields (86-99%). Chirality 26:21-26, 2013. 2013 Wiley Periodicals, Inc.
Fundamental insights into the enantioselectivity of hydrogenations on cinchona-modified platinum and palladium
Schmidt, Erik,Bucher, Christoph,Santarossa, Gianluca,Mallat, Tamas,Gilmour, Ryan,Baiker, Alfons
, p. 238 - 248 (2012)
The influence of the configuration at the C8 and C9 positions of cinchona alkaloids was investigated by comparing the efficiency of cinchonidine, cinchonine, and 9-epi-cinchonidine as chiral modifiers. In the hydrogenation of ketones (methyl benzoylformate, ketopantolactone, methylglyoxal dimethylacetal, 2,2,2-trifluoroacetophenone) on Pt, a change in the configuration at C9 did not affect the absolute configuration of the main products; however, the ees and rates dropped significantly. In the hydrogenation of α-functionalized olefins (E-2-methyl-2-hexenoic acid, 2-phenylcinnamic acid, and 4-methoxy-6-methyl-2H-pyran-2-one) on Pd, replacement of cinchonidine or cinchonine by epi-cinchonidine diminished the rates and almost eliminated the enantioselection, indicating that a subtle combination of C8 and C9 configurations is required on Pd. DFT calculations of the adsorption of the modifiers and the nonlinear behavior of modifier mixtures revealed that the lower reaction rates observed for 9-epi-cinchonidine-modified surfaces cannot be related to different adsorption strength of this modifier. Additionally, substrate-modifier docking interactions are presented.
A mechanistic and structural analysis of the basis for high enantioselectivity in the oxazaborolidine-catalyzed reduction of trihalomethyl ketones by catecholborane
Corey,Link, John O.,Bakshi, Raman K.
, p. 7107 - 7110 (1992)
The rates and enantioselectivities of the reduction of a series of trihalomethyl ketones under catalysis by oxazaborolidine 2 can be explained in terms of structural and mechanistic analyses which are detailed herein and which have predictive value.
Bioreductive synthesis of perfluorinated chiral alcohols
Rosen, Thomas C.,Feldmann, Ralf,Dünkelmann, Pascal,Dau?mann, Thomas
, p. 4803 - 4806 (2006)
Perfluorinated chiral alcohols are interesting building blocks for pharmaceuticals and agrochemicals. Different chiral (R)- and (S)-configured perfluorinated alcohols were produced by asymmetric reduction of the corresponding ketones. Commercially available alcohol dehydrogenases were used as catalyst in combination with different cofactor regenerating systems. High selectivities of >99% were observed in most cases. The results also demonstrate the influence of the CF3 group on reactivity and enantioselectivity of alcohol dehydrogenases.
Catalytic asymmetric β-hydrogen transfer reduction of α-trifluoromethyl aromatic ketones with diethylzinc
Huang, Huayin,Zong, Hua,Bian, Guangling,Song, Ling
, p. 835 - 839 (2015)
Abstract The catalytic asymmetric β-hydrogen transfer reduction of α-trifluoromethyl ketones using diethylzinc as the β-hydrogen donor was developed with the use of phosphinamide chiral ligand. The corresponding alcohol products were afforded in good yields with up to 73% ee. This method was successfully applied to the chemo- and enantioselective reduction of α-methyl/trifluoromethyl diketone, affording 88% yield and 70% ee of the fluorinated hydroxylketone product.
Multiple cycle reaction mechanism in the enantioselective hydrogenation of α,α,α-trifluoromethyl ketones
Cakl,Reimann,Schmidt,Moreno,Mallat,Baiker
, p. 104 - 115 (2011)
The enantioselective hydrogenation of 2,2,2-trifluoroacetophenone (1) on cinchona-modified Pt, combined with the diastereoselective hydrogenation of cinchonidine and NMR analysis of the modifier-substrate-product interactions, revealed the key role of the
Asymmetric Ketone Reduction by Imine Reductases
Lenz, Maike,Meisner, Jan,Quertinmont, Leann,Lutz, Stefan,K?stner, Johannes,Nestl, Bettina M.
, p. 253 - 256 (2017)
The rapidly growing area of asymmetric imine reduction by imine reductases (IREDs) has provided alternative routes to chiral amines. Here we report the expansion of the reaction scope of IREDs by showing the stereoselective reduction of 2,2,2-trifluoroacetophenone. Assisted by an in silico analysis of energy barriers, we evaluated asymmetric hydrogenations of carbonyls and imines while considering the influence of substrate reactivity on the chemoselectivity of this novel class of reductases. We report the asymmetric reduction of C=N as well as C=O bonds catalysed by members of the IRED enzyme family.
Alkaloid-induced asymmetric hydrogenation on bimetallic Pt@Cu cathodes under electrochemical conditions
Yue, Ying-Na,Wu, Di,Zeng, Sheng,Yang, Man-Ping,Wang, Huan,Lu, Jia-Xing
, p. 7853 - 7856 (2017)
Bimetallic Pt@Cu nanoparticles (NPs) with low Pt loading obtained by reducing platinum precursors on Cu NPs were coated on carbon paper and used as a cathode for asymmetric hydrogenation by the electrochemical method. The Pt@Cu NPs exhibited enhanced cata
Artificial metalloenzymes derived from bovine β-lactoglobulin for the asymmetric transfer hydrogenation of an aryl ketone-synthesis, characterization and catalytic activity
Chevalley, Alice,Cherrier, Mickael V.,Fontecilla-Camps, Juan C.,Ghasemi, Mahsa,Salmain, Michele
, p. 5482 - 5489 (2014)
A series of diimines derived from saturated and unsaturated fatty acids and including a dipyridylamine (dpa) or a bispyridylmethane (bpm) scaffold as a chelating moiety were synthesized and characterized spectroscopically. Complexation by [LM(μ-Cl)Cl]sub
Light-mediated regulation of asymmetric reduction of ketones by a cyanobacterium
Nakamura, Kaoru,Yamanaka, Rio
, p. 2529 - 2533 (2002)
The stereochemical course of the asymmetric reduction of ketones by a photosynthetic microbe is largely regulated by light. Thus, we find that the enantioselectivity of the reduction of α,α-difluoroacetophenone with Synechococcus elongatus PCC 7942 increa
Effect of carbon dioxide concentrations on asymmetric reduction of ketones with plant-cultured cells
Kojima, Hideo,Okada, Akiko,Takeda, Satomi,Nakamura, Kaoru
, p. 7079 - 7081 (2009)
Enantioselectivities in asymmetric reduction of ketones were controlled by atmospheric carbon dioxide concentrations: the reaction in high carbon dioxide concentrations under illumination of fluorescent light afforded the corresponding l-alcohol while tha
Preparation and lipase-catalyzed optical resolution of 2,2,2-trifluoro-1-(naphthyl)ethanols
Kato,Katayama,Gautam,Fujii,Kimoto
, p. 271 - 276 (1995)
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First Enantioselective Hydrogenation of a Trifluoro-β-ketoester with Cinchona-Modified Platinum
Von Arx,Mallat,Baiker
, p. 161 - 164 (2000)
A series of trifluoromethyl ketones possessing different functional groups were hydrogenated over Pt/Al2O3 modified by cinchonidine and O-methylcinchonidine. The highest enantiomeric epcess of 90% was achieved in the hydrogenation of
Asymmetric Reduction of Trifluoromethyl and Methyl Ketones by Yeast; An Improved Method
Bucciarelli, Maria,Forni. Arrigo,Moretti, Irene,Torre, Giovanni
, p. 897 - 899 (1983)
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Magnetically separable Pt catalyst for asymmetric hydrogenation
Panella, Barbara,Vargas, Angelo,Baiker, Alfons
, p. 88 - 93 (2009)
A magnetic Pt/SiO2/Fe3O4 catalyst consisting of chirally modified platinum supported on silica coated magnetite nanoparticles was prepared using an easy synthetic route and successfully applied for the enantioselective hydrogenation of various activated ketones. The magnetic catalyst modified with cinchonidine showed a catalytic performance (activity, enantioselectivity) in the asymmetric hydrogenation of various activated ketones in toluene comparable to the best known Pt/alumina catalyst used for these reactions. The novel catalyst can be easily separated from the reaction solution by applying an external magnetic field and recycled several times with almost complete retention of activity and enantioselectivity.
Novel evidence on the role of the nucleophilic intermediate complex in the orito-reaction: Unexpected inversion in the enantioselective hydrogenation of 2,2,2-trifluoroacetophenone on Pt-Cinchona chiral catalyst using continuous-flow fixed-bed reactor
Sz?ll?si, Gyo?rgy,Cserényi, Szabolcs,Bartók, Mihály
, p. 264 - 269 (2010)
The enantioselective hydrogenation of 2,2,2,- trifluoroacetophenone over Pt/Al2O3 catalysts modified by cinchona alkaloids was investigated for the first time using continuous-flow fixed-bed reactor system in toluene/AcOH 9/1 solvent
Asymmetric transfer hydrogenation of ketones promoted by manganese(I) pre-catalysts supported by bidentate aminophosphines
Azouzi, Karim,Bruneau-Voisine, Antoine,Vendier, Laure,Sortais, Jean-Baptiste,Bastin, Stéphanie
, (2020/05/19)
A series of commercially available chiral amino-phosphines, in combination with Mn(CO)5Br, has been evaluated for the asymmetric reduction of ketones, using isopropanol as hydrogen source. With the most selective ligand, the corresponding manga
