1447-87-6Relevant academic research and scientific papers
Access to both enantiomers of substituted 2-tetralol analogs by a highly enantioselective reductase
Koesoema, Afifa Ayu,Matsuda, Tomoko,Standley, Daron M.,T. sriwong, Kotchakorn,Tamura, Mayumi
supporting information, (2020/02/11)
Both (S) and (R) forms of enantiomerically pure 2-tetralols, and their substituted analogs, are fundamental pharmaceutical intermediates. Here, we utilized the wild type and an engineered form of a highly enantioselective acetophenone reductase from Geotrichum candidum NBRC 4597 (GcAPRD) to produce (S)- and (R)-2-tetralols, and their substituted analogs. All mutations targeted residue Trp288, which has been shown to restrict substrate binding, but not play a direct role in catalysis. The wild type produced (S)-alcohols with excellent enantioselectivity, while the engineered forms produced either (S)- or (R)- alcohols, depending on the substituent on the aromatic ring of the substrate, indicating that enantioselectivity can be rationally controlled. As a result, we were able to produce 6-hydroxy-2-tetralol, a potential antifungal drug intermediate, with 98% ee (S) and 81% ee (R) by wild type and Trp288Ser GcAPRD, respectively. To our knowledge, this is the first report of generating chiral 6-hydroxy-2-tetralol by rational enzyme design.
Selective Catalytic Hydrogenation of Arenols by a Well-Defined Complex of Ruthenium and Phosphorus-Nitrogen PN3-Pincer Ligand Containing a Phenanthroline Backbone
Li, Huaifeng,Wang, Yuan,Lai, Zhiping,Huang, Kuo-Wei
, p. 4446 - 4450 (2017/07/24)
Selective catalytic hydrogenation of aromatic compounds is extremely challenging using transition-metal catalysts. Hydrogenation of arenols to substituted tetrahydronaphthols or cyclohexanols has been reported only with heterogeneous catalysts. Herein, we demonstrate the selective hydrogenation of arenols to the corresponding tetrahydronaphthols or cyclohexanols catalyzed by a phenanthroline-based PN3-ruthenium pincer catalyst.
Artificial multi-enzyme networks for the asymmetric amination of sec-alcohols
Tauber, Katharina,Fuchs, Michael,Sattler, Johann H.,Pitzer, Julia,Pressnitz, Desiree,Koszelewski, Dominik,Faber, Kurt,Pfeffer, Jan,Haas, Thomas,Kroutil, Wolfgang
supporting information, p. 4030 - 4035 (2013/04/10)
Various artificial network designs that involve biocatalysts were tested for the asymmetric amination of sec-alcohols to the corresponding α-chiral primary amines. The artificial systems tested involved three to five redox enzymes and were exemplary of a range of different sec-alcohol substrates. Alcohols were oxidised to the corresponding ketone by an alcohol dehydrogenase. The ketones were subsequently aminated by employing a ω-transaminase. Of special interest were redox-neutral designs in which the hydride abstracted in the oxidation step was reused in the amination step of the cascade. Under optimised conditions up to 91 % conversion of an alcohol to the amine was achieved. Trickle-down effect: The asymmetric amination of sec-alcohols to the corresponding α-chiral primary amines was performed with a biocatalytic cascade whereby the various steps were interconnected through the cofactors/cosubstrates. In a redox-neutral cascade and under optimised conditions, up to 91 % conversion of an alcohol to the amine was achieved. Copyright
Tetrahydroxynaphthalene reductase: Catalytic properties of an enzyme involved in reductive asymmetric naphthol dearomatization
Schaetzle, Michael A.,Flemming, Stephan,Husain, Syed Masood,Richter, Michael,Guenther, Stefan,Mueller, Michael
supporting information; experimental part, p. 2643 - 2646 (2012/05/04)
In reduced circumstances: Tetrahydroxynaphthalene reductase shows a broad substrate range including alternate phenolic compounds and cyclic ketones. Structural modeling reveals major enzyme-substrate interactions; C-terminal truncation of the enzyme causes an altered substrate preference, in accordance with stabilization of the substrate by the C-terminal carboxylate (see picture). This effect allows the identification of a homologous enzyme. Copyright
Regio- and stereoselective biohydroxylations with a recombinant escherichia coli expressing P450pyr monooxygenase of sphingomonas Sp. HXN-200
Zhang, Wei,Tang, Weng Lin,Wang, Zunsheng,Li, Zhi
experimental part, p. 3380 - 3390 (2011/02/23)
A recombinant Escherichia coli expressing P450pyr monooxygenase of Sphingomonas sp. HXN-200 was developed as a useful biocatalyst for regio- and stereoselective hydroxylations, with no side reaction and easy cell growth. The resting E. coli cells showed an activity of 4.1 U/g cdw and 9.9 U/g cdw for the hydroxylation of N-benzylpyrrolidin-2-one 1 and N-benzyloxycarbonylpyrrolidine 3, respectively, being as active as the wide-type strain. Biohydroxylation of N-benzylpyrrolidin-2-one 1 with the resting cells gave (S)-N-benzyl-4- hydroxypyrrolidin-2-one 2 in >99% ee and 10.8 mM, a 2.6 times increase of product concentration in comparison with the wild-type strain. Biohydroxylation of N-tert-butoxycarbonylpiperidin-2-one 5, N-benzylpiperidine 7 and N-tert-butoxycarbonylazetidine 9 with the E. coli cells afforded the corresponding 4-hydroxypiperidin-2-one 6, 4-hydroxypiperidine 8, and 3-hydroxyazetidine 10 in 14 mM, 17 mM, and 21 mM, respectively. Moreover, hydroxylation of (-)-β-pinene 11 with the recombinant E. coli cells showed excellent regio- and stereoselectivity and gave (1R)-trans-pinocarveol 12 in 82% yield and 4.1 mM, which is over 200 times higher than that obtained with the best biocatalytic system known thus far. The recombinant strain was also able to hydroxylate other types of substrates with unique selectivity: biohydroxylation of norbornane 13 gave exo-norbornaeol 14, with exo/endo selectivity of 95%; tetralin 15 and 6-methoxytetralin 17 were hydroxylated at the non-activated 2-position, for the first time, with regioselectivities of 83-84%. Copyright
Intramolecular photoarylation of alkenes by phenyl cations
Dichiarante, Valentina,Fagnoni, Maurizio,Mella, Mariella,Albini, Angelo
, p. 3905 - 3915 (2008/02/06)
Acetone-sensitized irradiation of various o-chlorophenyl allyl ethers in polar solvents led to either (dihydro)benzofurans or chromanes. The reaction appeared to involve photoheterolysis of the aryl-Cl bond followed by phenyl cation addition onto the tethered double bond either in 5-exo or 6-endo modes. The adduct cation gave the end products by deprotonation: addition of chloride anion or of the solvent, depending on the struc ture: and the conditions used. Preference for the 5-exo mode increased in passing from medium polarity (methylene chloride, ethyl acetate) to high polarity solvents (aqueous acetonitrile, methanol, 2,2,2-trifluoroethanol), for which this was often the exclusive path. The same compounds underwent photohomolysis when irradiated in cyclohexane, and radical cyclization was one of the process occurring. Substitution of a methylene group for the ether oxygen atom made 6-endo cyclization by far the main path in a related o-chlorophenylbutene. Again, the selectivity was higher in polar protic solvents. The results are discussed in terms of in cage ion pair versus free phenyl cation reactions.
Cyclialkylation of arylalkyl epoxides with solid acid catalysts
Elings, Jacob A.,Downing, Roger S.,Sheldon, Roger A.
, p. 837 - 846 (2007/10/03)
Solid acids, such as zeolites and clays, catalyse the intramolecular hydroxyalkylation (cyclialkylation) of several arylalkyl epoxides in moderate to excellent conversions and selectivities. The use of solid acids in these cyclialkylations provides a cleaner, better alternative to conventional Lewis and Bronsted acids, enabling a more facile workup of reaction mixtures and, in several cases, better selectivities.
Friedel-Crafts Cyclialkylations of Some Epoxides
Taylor, Stephen K.,Hockerman, Gregory H.,Karrick, Gregory L.,Lyle, Stephen B.,Schramm, Scott B.
, p. 2449 - 2452 (2007/10/02)
Several arylalkyl epoxides (1-9) were investigated for cyclialkylation reactions.Cyclialkylation to form six-membered rings was observed (up to 91 percent isolated yields) at secondary but not at primary epoxide positions.Cyclialkylation was not observed with 4-phenyl-1,2-epoxybutane, but a m-methoxy substituent did promote ring closure to the primary position in moderate yield.Cyclialkylation to seven-membered rings occurred at a secondary position in reasonable yields; less rearrangement occured with the epoxide system than with analogous alkylating agents such as phenylalk yl alcohols.Reduced skeletal rearrangement is characteristic of cyclization reactions that occur with epoxides and suggests that the epoxide serves to moderate electrophilic reactivity.Cyclialkylation to form five-membered rings was not observed with epoxides that were capable of ring-opening at primary or secondary positions.
Derivatives of 2-amino-(1,2,3,4-tetrahydronaphthalene), the preparation and use thereof
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, (2008/06/13)
This invention relates to new derivatives of 2-amino-(1,2,3,4-tetrahydronaphthalene), namely 2-[N-phenyl-N-(R1,R2 -aminoalkyl or alkanoyl)]-amino-(1,2,3,4-tetrahydronaphthalenes), in which R1 and R2 represent a
