A quinine-derived thiourea organocatalyst promoted the highly enantioselective addition of naphthols and activated phenols to ketimines derived from isatins. The reaction afforded chiral 3-amino-2-oxindoles with a quaternary stereocenter in high yields (up to 99%) with excellent enantioselectivity (up to 99%ee). To the best of our knowledge, this transformation is the first highly enantioselective addition of naphthols to ketimines.
Montesinos-Magraner, M., Vila, C., Cantõn, R., Blay, G., Fernández, I., Muñoz, M. C., & Pedro, J. R. (2015). Organocatalytic asymmetric addition of naphthols and electron-rich phenols to isatin-derived ketimines: Highly enantioselective construction of tetrasubstituted stereocenters. Angewandte Chemie - International Edition, 54(21), 6320–6324. https://doi.org/10.1002/anie.201501273