Organoselenium‐Catalyzed Oxidative Ring Expansion of Methylenecyclopropanes with Hydrogen Peroxide

Abstract Catalyst screening and optimization of reaction conditions allowed control of the organoselenium‐catalyzed oxidative ring expansion of highly active methylenecyclopropanes to give substituted cyclobutanones selectively. This protocol employs H 2 O 2 as a clean oxidant and generates no waste and, therefore, provides green access to useful, but not readily available, substituted cyclobutanones under mild conditions.