Biological activity, especially that related to the pathogenesis of Parkinson's disease, has recently renewed interest in tetrahydroisoquinolines (TIQs) and related natural isoquinoline alkaloids. 1. and 2. Since the enantiomers were observed to vary in activity, 3 the synthesis of chiral 1-substituted TIQ is the current focus in medicinal organic chemistry. 4 We have previously reported an approach to asymmetric synthesis of chiral 1-methyl and 1-phenyl TIQs ...