Amine‐Catalyzed Tandem Reactions of Morita–Baylis–Hillman Acetates with Isatins: Facile Synthesis of 3‐Hydroxyoxindoles
An amine-catalyzed reaction between Morita–Baylis–Hillman (MBH) acetates and isatins to provide facile access to structurally interesting 3-hydroxyoxindoles in moderate to good yields with diastereomeric ratios of 1:1 has been developed. A wide variety of isatin derivatives were tolerated under the conditions of this tandem reaction. Notably, the inert homoallylic methyl group of MBH acetate 1 was directly involved in the bond formation step, which was followed by a [4+2] annulation under mild conditions to lead to the desired products.