Key points are not available for this paper at this time.
2-Aryl-3H-indol-3-ones reacted with aldehydes or ketones in the presence of L-proline as a catalyst to give the corresponding aza-quaternary carbon addition product in good yield with moderate to excellent regioselectivity and enantioselectivity. The system was applied to the reaction of 2-(2-bromo-phenyl)-3H-indol-3-one and acetaldehyde to give 2-2-(2-bromophenyl)-3-oxoindolin-2-yl acetaldehyde, which is a precursor for the synthesis of some alkaloids such as hinckdentine A.
Xie et al. (Tue,) studied this question.