Organoselenium-Catalyzed Oxidative Ring Expansion of Methylenecyclopropanes with Hydrogen Peroxide

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 H2O2 as a clean oxidant and generates no waste and, therefore, provides green access to useful, but not readily available, substituted cyclobutanones under mild conditions.