Enantioselective Michael Addition of Malononitrile to Unsaturated Ketones Catalyzed by Rare-Earth Metal Amides RE[N(SiMe 3 ) 2 ] 3 with Phenoxy-Functionalized TsDPEN Ligands.

The catalytic enantioselective Michael addition of α,β-unsaturated ketones with malononitrile was well established using rare-earth metal amides RE[N(SiMe 3 ) 2 ] 3 (RE = Y, Eu, Sm, Nd, La) with chiral phenoxy-functionalized TsDPEN ligands. The combination of lanthanum amide La[N(SiMe 3 ) 2 ] 3 and chiral TsDPEN ligand H 3 L 1 [H 3 L 1 = N -((1 R ,2 R )-2-((3,5-di- tert -butyl-2-hydroxybenzyl)amino)-1,2-diphenylethyl)-4-methylbenzenesulfonamide] in a 1:1.5 molar ratio was proved to be the optimal partner in THF, which provided the desired β-carbonyl dinitriles in excellent yields and good to high enantioselectivities after 12 h at -15 °C.