Convenient asymmetric synthesis of both enantiomers of 3,4-disubstituted 3,4-dihydro-1,4-benzoxazin-2-ones
作者:Eunjee Youk、Wongi Park、Yong Sun Park
DOI:10.1080/00397911.2018.1444769
日期:2018.6.3
ABSTRACT Bothenantiomers of N-substituted 3-arylated 3,4-dihydro-1,4-benzoxazin-2-ones were conveniently synthesized up to 93:7 er based on the dynamic kinetic resolution of either (R)-pantolactone- or l-mandelate-derived α-bromo arylacetates in nucleophilic substitution with N-alkylated 2-aminophenols. GRAPHICAL ABSTRACT
摘要 基于 (R)-泛内酯-或 l 的动态动力学分辨率,N-取代的 3-芳基化 3,4-二氢-1,4-苯并恶嗪-2-酮的两种对映异构体均可方便地合成至 93:7 er。 -扁桃酸衍生的α-溴芳基乙酸酯与N-烷基化2-氨基苯酚亲核取代。图形概要
Dynamic resolution of α-halo chiral esters for the synthesis of 3-substituted piperazin-2-ones
作者:Jung In Jang、Seock Yong Kang、Kyoung Hee Kang、Yong Sun Park
DOI:10.1016/j.tet.2011.06.055
日期:2011.8
Dynamicresolution of α-halo esters derived from five chiral alcohols has been investigated in nucleophilicsubstitution with ethylenediamine nucleophiles. Stereoselective substitution of α-halo esters and following spontaneous cyclization provide a practical protocol for asymmetricsyntheses of 3-substituted piperazin-2-ones up to 94:6 er.
Facile Preparation of Highly Enantioenriched 1,4-Benzothiazin-3-ones by the Substitution of α-Bromoacetate with 2-Aminothiophenol
作者:Yong Sun Park、Ji Su Lee、So Jeong Lee、Gun Hee Han
DOI:10.1055/a-2004-1529
日期:——
A simple and convenient approach for highly enantioenriched 2-substituted 1,4-benzothiazin-3-ones was developed via the nucleophilic substitution of α-bromoacetates derived from either l-threonate or l-serinate using 2-aminothiophenol and a subsequent facile lactamization.
Diacetone-D-glucose-Mediated Asymmetric Syntheses of Dihydroquinoxalinones
作者:Yong Sun Park、Yongtae Kim、Min Hee Lee、Eui Ta Choi、Eun Sun No
DOI:10.3987/com-06-10910
日期:——
Asymmetric syntheses of N-substituted α-amino esters via dynamic kinetic resolution of α-haloacyl diacetone-d-glucose
作者:Hyun Jung Kim、Yongtae Kim、Eui Ta Choi、Min Hee Lee、Eun Sun No、Yong Sun Park
DOI:10.1016/j.tet.2006.04.045
日期:2006.6
Diacetone-d-glucose or d-allose mediated dynamic kinetic resolution of α-halo esters in nucleophilic substitution reaction has been investigated. Reactions with various amine nucleophiles in the presence of TBAI and DIEA can provide the N-substituted α-amino esters up to 99:1 dr. Stereochemical models of transition states, taking into account a hydrogen bonding, are proposed on the basis of the observed results. Also