Modular Access to Eight‐Membered N‐Heterocycles by Directed Carbonylative C−C Bond Activation of Aminocyclopropanes

Aminocyclopropanes equipped with pendant nucleophiles undergo carbonylative heterocyclization triggered by C−C bond activation to generate eight‐membered N‐heterocycles. In these processes, intramolecular “capture” of a rhodacyclopentanone intermediate by an aryl or N‐based nucleophile is followed by C−C or C−N bond‐forming “collapse” to the targets. These studies demonstrate how the combination of cyclopropane strain release and the templating effect of catalytically generated metallacycles can be harnessed to enable otherwise challenging medium ring closures. Striking a happy medium: “Capture‐collapse” heterocyclizations of aminocyclopropanes equipped with pendant nucleophiles have been used to generate eight‐membered rings. The strategy relies on intramolecular “capture” of a rhodacyclopentanone intermediate by an aryl or N‐based nucleophile followed by C−C or C−N bond‐forming “collapse” to the targets.