Enantioselective Construction of Tetrasubstituted Carbon Stereocenters via Chiral Phosphoric Acid-Catalyzed Friedel–Craft Alkylation of Indoles with 5-Substituted Hydroxybutyrolactams
Résumé
The first intermolecular organocatalytic enantioselective addition of indoles to prochiral 5-membered cyclic N-acyliminium ions, generated from 5-hydroxy-,-unsaturated pyrrolidin-2-ones is reported hereinafter. The reaction proceeds smoothly with a range of 5-hydroxy-5-substituted-,-unsaturated pyrrolidin-2-ones and indoles using BINOL-derived phosphoric acid catalyst to afford ,-unsaturated lactams embedding a tetrasubstituted stereogenic center in high yields and enantioselectivities