- High Regio- and Stereoselective Multi-enzymatic Synthesis of All Phenylpropanolamine Stereoisomers from β-Methylstyrene
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We present a one-pot cascade for the synthesis of phenylpropanolamines (PPAs) in high optical purities (er and dr up to >99.5 %) and analytical yields (up to 95 %) by using 1-phenylpropane-1,2-diols as key intermediates. This bioamination entails the combination of an alcohol dehydrogenase (ADH), an ω-transaminase (ωTA) and an alanine dehydrogenase to create a redox-neutral network, which harnesses the exquisite and complementary regio- and stereo-selectivities of the selected ADHs and ωTAs. The requisite 1-phenylpropane-1,2-diol intermediates were obtained from trans- or cis-β-methylstyrene by combining a styrene monooxygenase with epoxide hydrolases. Furthermore, in selected cases, the envisioned cascade enabled to obtain the structural isomer (1S,2R)-1-amino-1-phenylpropan-2-ol in high optical purity (er and dr >99.5 %). This is the first report on an enzymatic method that enables to obtain all of the four possible PPA stereoisomers in great enantio- and diastereo-selectivity.
- Corrado, Maria L.,Knaus, Tanja,Mutti, Francesco G.
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p. 2345 - 2350
(2021/05/17)
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- Regio- and stereoselective multi-enzymatic aminohydroxylation of β-methylstyrene using dioxygen, ammonia and formate
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We report an enzymatic route for the formal regio- and stereoselective aminohydroxylation of β-methylstyrene that consumes only dioxygen, ammonia and formate; carbonate is the by-product. The biocascade entails highly selective epoxidation, hydrolysis and hydrogen-borrowing alcohol amination. Thus, β-methylstyrene was converted into 1R,2R and 1S,2R-phenylpropanolamine in 59-63% isolated yields, and up to >99.5 : 0.5 dr and er.
- Corrado, Maria L.,Knaus, Tanja,Mutti, Francesco G.
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supporting information
p. 6246 - 6251
(2019/12/03)
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- Examining the origin of selectivity in the reaction of racemic alcohols with chiral N-phosphoryl oxazolidinones
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A range of known and novel N-phosphoryl oxazolidinones and imidazolidinones were prepared and screened in the kinetic resolution of a range of racemic magnesium chloroalkoxides. Models are proposed to account for the enantioselectivity achieved based on a combination of chiral relay effects, generation of transient stereochemistry and the structure of the intermediate magnesium alkoxide.
- Crook, Samuel,Parr, Nigel J.,Simmons, Jonathan,Jones, Simon
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p. 1298 - 1308
(2015/01/09)
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- Enantioselective synthesis of cyclic sulfamidates by using chiral rhodium-catalyzed asymmetric transfer hydrogenation
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Asymmetric transfer hydrogenation (ATH) of cyclic sulfamidate imines 4 and 9, using a HCO2H/Et3N mixture as the hydrogen source and well-defined chiral Rh catalysts (S,S)- or (R,R)-2, CpRhCl(TsDPEN), effectively produces the corresponding cyclic sulfamidates with excellent yields and enantioselectivities at room temperature within 0.5 h. ATH of 4,5-disubstituted imines 9, having preexisting stereogenic centers, is shown to take place with dynamic kinetic resolution.
- Kang, Soyeong,Han, Juae,Lee, Eun Sil,Choi, Eun Bok,Lee, Hyeon-Kyu
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supporting information; experimental part
p. 4184 - 4187
(2010/11/19)
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- Platinum-Catalyzed Intramolecular Hydrosilation of Allylamines: Formation of 1-Aza-2-silacyclobutanes and Application to Stereoselective Synthesis of 2-Amino Alcohols
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N,N-Bis(dimethylsilyl)allylamines undergo intramolecular hydrosilation in the presence of Pt2O>2 (0.2 mol percent) to form four-membered cyclic compounds, 1-aza-2-silacyclobutane derivatives, which can be transformed into 2-amino alcohols by oxidation with 30percent H2O2 in the presence of KF and KHCO3.
- Tamao, Kohei,Nakagawa, Yoshiki,Ito, Yoshihiko
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p. 3438 - 3439
(2007/10/02)
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- DIASTEREOSELECTIVE PREPARATION OF ANTI-β-AMINO ALCOHOLS VIA MICHAEL ADDITION OF ALKOXIDE ANIONS TO NITROOLEFINS AND SUBSEQUENT HYDROGENATION REACTION
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Diastereoselective conjugate addition of benzylalkoxide anion to nitroolefins and subsequent hydrogenation reaction provide a new convenient method for the preparation of anti-β-amino alcohols.
- Kamimura, Akio,Ono, Noboru
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p. 731 - 734
(2007/10/02)
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- STEREOSELECTIVE CATALYTIC HYDROGENERATION OF alpha -HYDROXY KETOXIMES.
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Two isomers (E and Z) of benzoin oxime and 2-hydroxy-1-phenyl-1-propanone oxime were catalytically hydrogenated by using palladium on charcoal and erythro amino alcohols were obtained in about 80% diastereomeric excess. The syn-anti isomerization of these oximes in the presence of palladium on charcoal was also studied in connection with the stereoselectivity of the catalytic hydrogenation of the oximes.
- Harada,Shiono
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p. 1040 - 1045
(2007/10/02)
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