Synfacts 2008(6): 0642-0642  
DOI: 10.1055/s-2007-1072758
Organo- and Biocatalysis
© Georg Thieme Verlag Stuttgart · New York

Catalytic Asymmetric Phase-Transfer Hydroxylation of Oxindoles

Contributor(s): Benjamin List, Kristina Zumbansen
D. Sano, K. Nagata, T. Itoh*
Showa University, Tokyo, Japan
Further Information

Publication History

Publication Date:
21 May 2008 (online)

Significance

An asymmetric hydroxylation of oxindoles catalyzed by a phase-transfer catalyst is presented. Several different phase-transfer catalysts were tested. High chemical yields and good enantioselectivities were obtained using the cinchonidine-derived PTC-1. It was found that alkyl-, alkenyl- and alkynyl-substituted oxindoles gave high yields and high enantioselectivities. Remarkably, ester groups do not undergo hydrolysis under these conditions and are suitable compounds for this method.