Chiral PhosphoricAcid Catalyzed Asymmetric MannichReaction of 2‑Aryl‑3<i>H</i>‑indol-3-oneswith α‑H Diazoacetates

An asymmetric Mannich reaction between 2-aryl-3<i>H</i>-indol-3-ones and α-H diazoacetates catalyzed by chiral phosphoric acid was developed. This strategy achieves the effective synthesis of chiral 2,2-disubstituted indolin-3-ones bearing a quaternary stereocenter and containing a diazo group in the C2 substituent (up to >99% ee and 82% yield). To demonstrate the importance of the synthesized 2,2-disubstituted indolin-3-ones and the diversity of their diazo group reactions, we successfully achieved the relevant transformation reactions with a diazo group (such as hydroxylation, hydrogenation, intramolecular cyclization, etc.) in the C2 substituent.