Amine‐Catalyzed Tandem Reactions of Morita–Baylis–Hillman Acetates with Isatins: Facile Synthesis of 3‐Hydroxyoxindoles

Abstract

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.

Engineering the simply asymmetric Morita–Baylis–Hillman reactions in a sodium phosphate buffer system: from enzyme‐ to proline‐catalyzed transformation

“…The MBH reaction catalyzed by organic catalysts is a straightforward method for the synthesis of functionalized allylic alcohols from simple aldehydes and electron‐deficient alkenes 5 . The traditional catalysts for synthetic use are Lewis bases such as chiral amine and phosphine catalysts, Lewis acids and Brønsted acid catalysts such as chiral thioureas, proline derivatives and thiols 6‐12 . The main drawback of the synthetic reaction is the long reaction time (usually days).…”