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Paper | Regular issue | Vol 78, No. 9, 2009, pp.2233-2244
Published online, 11th May, 2009
DOI: 10.3987/COM-09-11700
(S)-Mandelate-Mediated Dynamic Kinetic Resolution of α-Bromo Esters for Asymmetric Syntheses of Aminoflavones, Dihydroquinoxalinones and Dihydrobenzoxazinones

Yoon Min Lee and Yong Sun Park*

*Department of Chemistry, Bio/Molecular Informatics Center, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701, Korea

Abstract

(S)-Mandelate-mediated dynamic kinetic resolution of α-bromo esters in nucleophilic substitution reaction has been investigated. Reactions of various aryl amine nucleophiles in the presence of TBAI and DIEA can provide the substitution products 2 and 7-19 up to 95% yield and 96:4 dr. Also, the simple procedure with spontaneous removal of the chiral auxiliary provides a practical protocol for asymmetric syntheses of dihydroquinoxalinones 20-26 and dihydrobenzoxazinones 27-30 up to 97:3 er.