Radical Heterocyclization and Heterocyclization Cascades Triggered by Electron Transfer to Amide-Type Carbonyl Compounds.

Radical heterocyclizations triggered by electron transfer to amide-type carbonyls, using SmI -H O, provide straightforward access to bicyclic heterocyclic scaffolds containing bridgehead nitrogen centers. Furthermore, the first radical heterocyclization cascade triggered by reduction of amide-type carbonyls delivers novel, complex tetracyclic architectures containing five contiguous stereocenters with excellent diastereocontrol.