Radical Ring-Opening of Oxetanes Enabled by Co-Catalysis

Abstract

Oxetanes are valuable building blocks due to their well-explored propensity to undergo ring-opening reactions with diverse nucleophiles. However, their application as precursors of radical species remains unexplored. Herein, we present a cobalt catalysis-based strategy to access various modes of radical reactivity via oxetane ring opening. The developed method involves formation of an alkylated Co-complex intermediate from vitamin B12 and oxetane. Homolytic cleavage of the Co-C bond generates nucleophilic radicals that engage in reactions with SOMOphiles and low-valent transition metals. The scope of the developed reactions is broad with various functional groups being well tolerated. Importantly, the regioselectivity of these processes complements known methodologies.

Recent Progress on Transition-Metal-Mediated Reductive C(sp3)–O Bond Radical Addition and Coupling Reactions

“…These radicals then underwent conjugate addition and coupling with aryl halides under Ni-reductive conditions to generate C(sp 3 )–C bonds. 13…”