Transition Metal‐Free Radical α‐Oxy C−H Cyclobutylation via Photoinduced Hydrogen Atom Transfer

Abstract A transition‐metal‐free photoinduced radical‐mediated α‐oxy C−H cyclobutylation reaction of bicyclo[1.1.0]butane (BCB) compounds was described. In this protocol, α‐oxy C( sp 3 )−H motifs including ethers and alcohols were activated via photocatalytic conditions, releasing the ring strain of BCBs and generating 1,3‐disubstituted cyclobutanes in 40–80% yields. Control experiments and Stern‐Volmer quenching experiments indicated that the reaction proceeded through the generation of α‐oxy carbon‐centered radical intermediates by photoinduced hydrogen atom transfer (HAT) process. magnified image