Adition of 2-oxazolidinones to arylidenecyclopropanes: A highly efficient method for the preparation of GEM-aryl disubstituted homoallylic oxazolidinones

The copper-catalyzed reaction of arylidenecyclopropanes (1) with 2-oxazolidinone (2) gave the corresponding homoallylic oxazolidinones (3) in good to high yields. For example, the reaction of diphenylmethylenecyclopropane (1a), {bis(p-tolyl)methylenecyclopropane (1b), and {bis(p-anisyl)methylene}-cyclopropane (1d) in the presence of 10 mol% of Cu(OTf)₂ without solvent proceeded at 120°C, giving the corresponding homoallylic oxazolidinones (3a, 3b, and 3d) in 89, 80, and 58% yields, respectively.