Intramolecular radical non-reductive alkylation of ketones via transient enamines

Abstract

Radical cyclization of dichloroacetamide-tethered ketones using pyrrolidine, AIBN and TTMSS under microwave activation gave 2-azabicyclo[3.3.1]nonan-3,6-diones. In a five-minute one-pot process, after the generation of an enamine, intramolecular addition of a carbamoylchloromethyl radical, and oxidation of the α-aminoalkyl radical intermediate, the resulting iminium salt evolved to the corresponding enamine and, after a workup, to the alkylated ketone.