I₂–DMSO‐Mediated Multicomponent [2+1+1+1] Annulation Reaction via Ethyl Nitroacetate C—NO₂ Bond Cleavage as a C1 Synthon: A Route to Multisubstituted β‐Pyrrolidinones Derivatives with a Quaternary Center

Comprehensive SummaryA [2 + 1 + 1 + 1] cyclization reaction has been developed for the synthesis of multisubstituted β‐pyrrolidinones from commercially available aryl methyl ketones, primary amines, and ethyl nitroacetate. In this I2–DMSO‐meditated process, the C—NO2 bond of ethyl nitroacetate is cleaved, affording a C1 synthon, and the formation of two C—C and two C—N bonds and a quaternary carbon center are constructed in one pot. This method has good substrate compatibility and permits the late‐stage modification of pharmaceutical compounds.