Enantioselective addition of organometallic compounds to 3,4-dihydroisoquinoline in the presence of oxazoline derivatives: synthesis of (R)-(+)- and (S)-(−)-salsolidine

The (R)- and (S)-enantiomers of salsolidine, 2, were prepared in good yield and moderate enantioselectivity (33 and 27% e.e., respectively) by the addition of methyllithium to 6,7-dimethoxy-3,4-dihydroisoqiunoline 1 in the presence of the chiral oxazoline ligands 4 and 10.