Stereocontrolled metalloenamine alkylations: application to the asymmetric synthesis of 4-alkyl-1,2,3,4-tetrahydroisoquinolines

摘要

A procedure for the asymmetric synthesis of 4-alkyl-1,2,3,4-tetrahydroisoquinolines is described. The key step in the synthetic route is a stereocontrolled metalloenamine alkylation using (R)-(+)-phenyl-glycinol methyl ether as the chiral auxiliary. Subsequent N-methylation, hydrogenolysis and cyclization afforded the target heterocycles with enantiomeric excesses higher than 99%. (C) 2000 Elsevier Science Ltd. All rights reserved. [References: 60]