Expanding the Reactivity of Bifunctional Reagents: Photoinduced Access to Imino Carbonyl Compounds and Tetrahydrofurans

Abstract Alkoxy radicals are versatile intermediates capable of engaging in diverse reaction pathways; however, the selective exploitation of their reactivity under mild conditions remains a significant challenge. Herein, we expand the synthetic utility of N-oxime-derived bifunctional radical reagents by exploiting two complementary alkoxy radical pathways, β-scission and intramolecular alkene cyclization, in combination with the metal-free radical 1,2-carboimination of activated alkenes. Under visible-light irradiation using 5CzBN as an organic photocatalyst, the bifunctional precursors generate alkoxy radicals that undergo substrate-controlled β-scission or cyclization to produce carbon-centered radicals, which are regioselectively trapped by activated alkenes and subsequently coupled with iminyl radicals. This modular strategy provides direct access to remotely imino-functionalized carbonyl compounds and tetrahydrofurans with broad substrate scope and excellent chemoselectivity, including in the late-stage functionalization of complex biomolecules and pharmaceuticals. Mechanistic studies support an energy-transfer-initiated radical-chain mechanism.