Asymmetric catalysis with substitutionally labile yet stereochemically stable chiral-at-metal iridium(III) complex.

摘要: A metal-coordination-based high performance asymmetric catalyst utilizing metal centrochirality as the sole element of chirality is reported. The introduced substitutionally labile chiral-at-metal octahedral iridium(III) complex exclusively bears achiral ligands and effectively catalyzes enantioselective Friedel–Crafts addition indoles to α,β-unsaturated 2-acyl imidazoles (19 examples) with yields (75%–99%) enantioselectivities (90–98% ee) at low loadings (0.25–2 mol %). Counterintuitively, despite its substitutional lability, which mechanistically required for coordination imidazole substrate, metal-centered maintained throughout catalysis. This novel class reactive complexes will likely be value a large variety transformations.