N. J. O'reilly, W. S. Derwin, Henry C. Lin
1990
Citations
0
Influential Citations
18
Citations
Journal
Synthesis
Abstract
(S)-Dimethoxy-1,2,3,4-tetrahydro-3-isoquinolinecarboxylic acid has been prepared in optically pure form as its hydrochloride. Pictet-Spengler ring closure of the optically pure (S)-2-amino-3-(3,4-dimethoxyphenyl)propanoic acid hydrochloride salt (L-3,4-dimethoxyphenylalanine hydrochloride) proceeded without significant racemization. A simple and safe, asymmetric hydrogenation catalyst system has been developed which allows the rapid screening of various chiral phosphine ligands via an in situ ionic complex. A protocol was demonstrated which uses a statistical approach to consider the effects of changes in solvent, nitrogen substituent, oxygen substituent, and ligand in the asymmetric hydrogenation of alkyl or aryl (Z)-2-acylamino-3-(3,4-dimethoxyphenyl)-2-propenoate derivatives. This method was used to successfully determine the optimal substrate and conditions for the preparation of enantiomerically pure (S)-2-amino-3-(3,4-dimethoxyphenyl)propanoic acid hydrochloride salt