Asymmetric Friedel–Crafts alkylation of indoles with β-nitrostyrenes catalyzed by a chiral NiII complex based on (S)-(2-aminomethyl)pyrrolidine and 3,5-di-tert-butylsalicylaldehyde
Abstract:
μ-(Acetato)nickel(II) complex with Schiff base of (S)-(2-aminomethyl)pyrrolidine and 3,5-di-tert-butyl-2-hydroxybenzaldehyde as the chiral ligand was tested in the asymmetric Friedel–Crafts alkylation of indoles with β-nitrostyrenes. The reactions catalyzed by 5 mol% of the complex provided the corresponding 3-(1-aryl-2-nitroethyl)indoles with up to 98% yields and up to 69% ee values.
Keywords:asymmetric Friedel–Crafts alkylation, indoles, β-nitrostyrenes, chiral nickel(II) complex, Lewis acids.