External chiral ligand-induced enantioselective lithiation/SE2 reactions of isochroman and phthalan
作者:Katsuhiko Tomooka、Lan-Fang Wang、Fumiaki Okazaki、Takeshi Nakai
DOI:10.1016/s0040-4039(00)01028-5
日期:2000.8
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 a-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. (C) 2000 Elsevier Science Ltd. All rights reserved.