Harnessing Diazo Compounds as Alkoxycarbonyl Methylene Radical Linchpins: Truce–Smiles Rearrangement toward Amido Esters and Isoquinolinedione Scaffolds

The radical reactivity of acceptor-type diazo compounds is harnessed in the photochemical Truce–Smiles rearrangement of N-aryl-N-arylsulfonyl acrylamides to access β,β′-disubstituted amido esters. The rational design of starting materials and the cascade technique can be extended to yield isoquinolinediones to display atropisomerism. Mechanistic investigations support a radical-mediated proton-coupled electron transfer (PCET) process involving intramolecular migration of an aryl radical via a spiro intermediate. This protocol shows the untapped potential of diazo chemistry for radical-based transformations beyond traditional carbene pathways.