SYNTHESIS OF CHIRAL 1,3-DISUBSTITUTED TETRAHYDROISOQUINOLINES AND THEIR USE IN THE ASYMMETRIC ADDITION OF DIETHYLZINC TO ALDEHYDES

摘要

The effects of modifications on three sites of 1-(1,2,3,4-tetrahydro-isoquinolin-1-yl)-naphthalen-2-ol (THIQNOL) chiral ligands the asymmetric diethylzinc additions were examined. The studies showed that modifications at the nitrogen only reduce the efficiency of these types of ligands, whereas modifications at the 3-position of the 1,2,3,4-tetrahydroisoquinoline ring and the 3-position of the naphthol ring can lead to chiral ligands which provide better enantioselectivities. In general, the use of a simple phenyl group on the 1,2,3,4-tetrahydroisoquinoline ring and either a phenyl or methoxyphenyl on the naphthol ring generates more effective chiral ligands for the asymmetric addition of diethylzinc to aldehydes.