Unexpected cyclization of ortho -nitrochalcones into 2-alkylideneindolin-3-ones.
Nicolai A AksenovDmitrii A AksenovNikolai A ArutiunovDaria S AksenovaAlexander V AksenovMichael RubinPublished in: RSC advances (2020)
An original, facile, and highly efficient method for the preparation of 2-(3-oxoindolin-2-ylidene)acetonitriles from ortho -nitrochalcones is described. The featured transformation is a triggered Michael addition of the cyanide anion to the chalcone followed by a cascade cyclization mechanistically related to the Baeyer-Drewson reaction.