Abstract
Mn(III)-based oxidative free-radical tandem cyclizations and annulations can be terminated by addition to nitriles. Cyclopentanones 20a (51%), 24a (57%), and 32a (54%) are formed in good yield. Annulation to give cyclohexanone 32b (41%) proceeds in moderate yield, although 20b (8%) and 24b (13%) are formed in poor yield in tandem cyclizations. Pyridine 39 (15%) is formed in ethanol by condensation of the enamine tautomer 37 of imine 31a with the oxidation byproduct 33a produced from radical 29a.