Catalytic Asymmetric Electrophilic Cyanation of 3-Substituted Oxindoles.

The first example of catalytic asymmetric electrophilic cyanation of 3-substituted oxindoles has been achieved using readily accessible 4-acetylphenyl cyanate as the cyano source. Thus, a series of all-carbon quaternary center 3-aryl-3-cyano oxindoles were prepared using a zinc complex of a chiral pincer ligand as the catalyst in high yields (up to 95%) and excellent enantioselectivities (up to >99% ee) in the presence of 4 Å MS and 2,6-lutidine in THF at 0 °C.