Copper(I)-Catalyzed Three Component Reaction of Sulfonyl Azide, Alkyne, and Nitrone Cycloaddition/Rearrangement Cascades: A Novel One-Step Synthesis of Imidazolidin-4-ones

A novel one-pot azide-alkyne/ketenimine-nitrone cycloaddition sequence that is induced by copper(I) and allows the transformation of sulfonyl azides, alkynes, and nitrones to highly substituted imidazolidin-4-ones is described. The corresponding heterogeneous version utilizing Cu(I)-modified zeolites as recyclable heterogeneous catalysts shows marginally improved yield and diastereoselectivity.