Access to Enantioenriched Molecules with Diverse Fluorinated Tetrasubstituted Stereocenters Using Hydroxy as Kinetic Resolution Auxiliary Group

2022 ◽  
Author(s):  
Xinqiang Fang ◽  
Syeda Tazeen Zehra ◽  
Shouang Lan ◽  
Hao Zhang ◽  
Jinggong Liu ◽  
...  
Keyword(s):  
Kinetic Resolution ◽  
Carbon Molecules ◽  
Optically Pure ◽  
General Method

Developing a general method affording optically pure fully-substituted carbon molecules bearing various fluorinated groups is highly important but very challenging. Here we show that using secondary OH as the kinetic...

scholarly journals ω-Amino Acid:Pyruvate Transaminase from Alcaligenes denitrificans Y2k-2: a New Catalyst for Kinetic Resolution of β-Amino Acids and Amines

2004 ◽  
Vol 70 (4) ◽  
pp. 2529-2534 ◽  
Author(s):  
Hyungdon Yun ◽  
Seongyop Lim ◽  
Byung-Kwan Cho ◽  
Byung-Gee Kim
Keyword(s):  
Amino Acids ◽  
Kinetic Resolution ◽  
Specific Activity ◽  
Expression System ◽  
Enantiomeric Excess ◽  
Selective Enrichment ◽  
Alcaligenes Denitrificans ◽  
Keto Acids ◽  
Optically Pure ◽  
High Stereoselectivity

ABSTRACT Alcaligenes denitrificans Y2k-2 was obtained by selective enrichment followed by screening from soil samples, which showed ω-amino acid:pyruvate transaminase activity, to kinetically resolve aliphatic β-amino acid, and the corresponding structural gene (aptA) was cloned. The gene was functionally expressed in Escherichia coli BL21 by using an isopropyl-β-d-thiogalactopyranoside (IPTG)-inducible pET expression system (9.6 U/mg), and the recombinant AptA was purified to show a specific activity of 77.2 U/mg for l-β-amino-n-butyric acid (l-β-ABA). The enzyme converts various β-amino acids and amines to the corresponding β-keto acids and ketones by using pyruvate as an amine acceptor. The apparent Km and V max for l-β-ABA were 56 mM and 500 U/mg, respectively, in the presence of 10 mM pyruvate. In the presence of 10 mM l-β-ABA, the apparent Km and V max for pyruvate were 11 mM and 370 U/mg, respectively. The enzyme exhibits high stereoselectivity (E > 80) in the kinetic resolution of 50 mM d,l-β-ABA, producing optically pure d-β-ABA (99% enantiomeric excess) with 53% conversion.

One-pot kinetic resolution–Mitsunobu reaction to access optically pure compounds, using silver salts in the substitution protocol

2020 ◽  
Vol 44 (48) ◽  
pp. 21238-21243
Author(s):  
Hiten B. Raval ◽  
Ashutosh V. Bedekar
Keyword(s):  
Kinetic Resolution ◽  
Mitsunobu Reaction ◽  
One Pot ◽  
Silver Salts ◽  
Pure Compounds ◽  
Optically Pure

Racemic carbinols were converted to chirally pure acetates by a combination of one-pot, enzyme mediated KR and Mitsunobu reaction with metal acetates. Use of AoNO3 or mixture with NaOAc gave excellent results. The protocol is further extended to introduce azide in place of acetate.

Esters of arylpropionic acids with 1,2:5,6-di-O-isopropylidene- and 1,2-O-isopropylidene-α-D-glucofuranose

1987 ◽  
Vol 52 (3) ◽  
pp. 766-774 ◽  
Author(s):  
Jiří Svoboda ◽  
Karel Čapek ◽  
Jaroslav Paleček
Keyword(s):  
Fractional Crystallization ◽  
Kinetic Resolution ◽  
Methyl Esters ◽  
Optically Pure ◽  
Derivatives Of

On fractional crystallization of 3-O-(2-(2-fluoro-4-biphenylyl)propionyl)-, 3-O-(2-(4-isobutylphenyl)propionyl)- and 3-O-(2-(6-methoxy-2-naphthyl)propionyl)-1,2 :5,6-di-O-isopropylidene-α-D-glucofuranoses V-VII optically pure R-diastereoisomers were isolated. The derivatives of 1,2-O-isopropylidene-α-D-glucofuranose obtained on partial deacetylation of esters V-VII were separated chromatographically to R and S-diastereoisomers. Their hydrolysis or transesterification afforded optically pure arylpropionic acids or their methyl esters, respectively. Kinetic resolution of the acids gives rise to esters V-VII enriched in R-diastereoisomer.

scholarly journals Conversion of racemic alcohols to optically pure amine precursors enabled by catalyst dynamic kinetic resolution: experiment and computation

2020 ◽  
Vol 56 (64) ◽  
pp. 9094-9097
Author(s):  
Luis Miguel Azofra ◽  
Mai Anh Tran ◽  
Viktoriia Zubar ◽  
Luigi Cavallo ◽  
Magnus Rueping ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Base Metal ◽  
Kinetic Resolution ◽  
Dynamic Kinetic Resolution ◽  
Chiral Amine ◽  
Optically Pure

An unprecedented base metal catalysed asymmetric synthesis of α-chiral amine precursors from racemic alcohols is reported.

Application of the Bimodal Meso/Macroporous Composite Synthesized from MCM-41 Sol

2007 ◽  
Vol 7 (11) ◽  
pp. 3876-3879 ◽  
Author(s):  
Chang-Kyo Shin ◽  
Rahul B. Kawthekar ◽  
Geon-Joong Kim
Keyword(s):  
Mesoporous Silica ◽  
Kinetic Resolution ◽  
Three Dimensional ◽  
Porous Silica ◽  
Pore System ◽  
Silica Monoliths ◽  
Micrometer Size ◽  
Silica Wall ◽  
Optically Pure ◽  
Mcm 41

A route to synthesize porous materials with a bimodal macro/mesoscopic pore system has been investigated in this work. Polystyrene with sub-micrometer size was used as a template in the synthesis. The resulting mesoporous silica wall replicated inversely the morphology of polystyrene template and had highly ordered three-dimensional arrays of macro pores. Large and moldable meso/macro porous silica monoliths could be obtained in centimeter scale by using monodispersed polystyrene beads and MCM-41 sol solutions. These bimodal structured porous silicates have been used as supports for asymmetric kinetic resolution of racemic epoxides to synthesize optically pure epoxide.

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