Ba black sheep: We have developed novel barium/binol catalysts prepared from alkaline earth metal amides and chiral binaphthol ligands. These catalysts effectively promoted the asymmetric Friedel–Crafts–typealkylationreactions of indoles with chalconederivatives. This is the first example of asymmetric Friedel–Crafts–typealkylationreactionsusingchiral Brønsted bases.
Chiral Brønsted acid catalyzed asymmetric Friedel–Crafts alkylation reaction of indoles with α,β-unsaturated ketones: short access to optically active 2- and 3-substituted indole derivatives
The asymmetric Friedel–Crafts alkylation reaction of indoles with α,β-unsaturated ketones catalyzed by chiral phosphoric acid is reported. A wide range of indoles and 4,7-dihydroindoles were allowed to react with α,β-unsaturated ketones to give the corresponding 1,4-adducts in good to high chemical yields and with excellent enantioselectivities.