External chiral ligand-induced enantioselective lithiation/SE2 reactions of isochroman and phthalan

Treatment of isochroman and phthalan with a t-BuLi/chiral bis(oxazoline) complex followed by reaction with carbon-electrophiles such as benzaldehyde and CO2 is shown to afford the α-substituted derivatives in moderate-to-high enantioselectivities (up to 97% ee and 83% ee, respectively). The asymmetric induction is proved to occur at the post-lithiation step.