Enantioselective Friedel–Crafts Reaction of Acylpyrroles with Glyoxylates Catalyzed by BINOL–Ti(IV) Complexes
作者:Jakub Majer、Piotr Kwiatkowski、Janusz Jurczak
DOI:10.1021/ol202244u
日期:2011.11.18
We report the first efficient enantioselective Friedel-Crafts hydroxyalkylation of pyrroles having one electron-withdrawing group at the alpha, beta or N-positions with alkyl glyoxylates catalyzed by readily available chiral BINOL-Ti(IV) complexes (1-5 mol %). The reaction regioselectively led to the desired pyrrole-hydroxyacetic acid derivatives with good yields (70-96%) and enantiomeric excesses up to 96%, and is applicable in multigram scale with low loading of the catalyst (1 mol %).