N-Amidopyridinium Salts as N-Radical Precursors for the Visible-Light-Promoted Radical Cascade Cyclization: Access to Amidated Phenanthridines

An effective photochemical protocol has been disclosed for the construction of amidated phenanthridines by using N-amidopyridinium salts as a source of the amidyl radical. The radical tandem cyclization proceeds under mild reaction conditions and exhibits broad functional group compatibility. This methodology facilitates the construction of the phenanthridine framework while simultaneously introducing the amidyl groups in a single synthetic step.