Chiral NHC Ligands Bearing a Pyridine Moiety in Copper-Catalyzed 1,2-Addition of Dialkylzinc Reagents to β-Aryl-α,β-unsaturated <i>N</i>-Tosylaldimines
作者:Takahiro Soeta、Tomohiro Ishizaka、Yutaka Ukaji
DOI:10.1021/acs.joc.6b00093
日期:2016.4.1
Asymmetric 1,2-addition of dialkylzincreagents to α,β-unsaturated N-tosylaldimines was catalyzed by copper salt in the presence of chiral imidazolium salts having a pyridine ring, which were derived from amino acid, to afford the corresponding chiral allylic amines with up to 91% ee in reasonably high yields. The chiralN-heterocycliccarbene (NHC) ligand played an important role in controlling chemoselectivity