Synthesis 2003(11): 1705-1706
DOI: 10.1055/s-2003-40886
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Enantioselective Synthesis of Protoberberine Alkaloids via (-)-Sparteine-mediated Asymmetric Condensation-Cyclisation of o-Toluamide Anions with 3,4-Dihydroisoquinolines

Ligong Liu*
Department of Research and Development, Progen Industries Ltd, PO Box 28, Richlands BC, Qld 4077, Australia
Fax: +61(7)3375 6746; e-Mail: ligong.liu@progen.com.au;
Further Information

Publication History

Received 30 June 2003
Publication Date:
25 July 2003 (online)

Abstract

The first asymmetric synthesis of protoberberine alkaloids based upon the (-)-sparteine-mediated lateral metalation of o-toluamides and subsequent addition-cyclisation with 3,4-dihydroisoquinolines is described (up to 77% ee).