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Short Paper | Special issue | Vol 99, No. 2, 2019, pp.1398-1411
Published online, 13th February, 2019
DOI: 10.3987/COM-18-S(F)87
Asymmetric Synthesis of t-Butyl 3-Alkyl-oxindole-3-carboxylates via Chiral Phosphoric Acid-Catalyzed Desymmetrization of Di-t-butyl 2-Alkyl-2-(2-aminophenyl)malonates

Kyoji Ishida, Masahiro Shimizu, Yu-suke Yamai, Itaru Natsutani, Shinichi Uesato, Yasuo Nagaoka, and Takaaki Sumiyoshi*

*Department of Life Science and Biotechnology, Faculty of Chemistry, Materials and Bioengineering, Kansai University, Yamate-cho 3-3-35, Suita, Osaka, 564-8680, Japan

Abstract

We describe the asymmetric desymmetrization of di-t-butyl 2-alkyl-2-(2-aminophenyl)malonates to prepare enantioenriched t-butyl 3-alkyl-oxindole-3-carboxylates using (S)-TRIP, a chiral phosphoric acid. Optimization study increased the enantioselectivity up to 66% ee.