Preparation of Indolin-3-one-Containing 1,4-Naphthoquinone Derivatives via Organocatalytic Asymmetric Michael Addition Reaction

This article explores the asymmetric Michael addition reaction of 2-hydroxy-1,4-naphthoquinone and indole-3-ones catalyzed by cinchona alkaloids. This strategy utilizes 2-hydroxy-1,4-naphthoquinone and easily prepared indole-3-one as substrates, resulting in the synthesis of 23 unprecedented indolin-3-ones bearing a 1,4-naphthoquinone unit at the C2 position of indole under simple and mild reaction conditions, with up to 88% yield, 98%