Synthesis of γ-Carbonyl Aliphatic Sulfoxonium Salts via Site-Selective Ring Opening of In Situ Formed 2-Sulfoxonium Cyclobutanone

We report herein a Rh-catalyzed tandem reaction between a pivaloyl-substituted sulfoxonium-iodonium ylide and diverse nucleophiles, enabling the efficient synthesis of γ-sulfoxonium carbonyl compounds, which were previously inaccessible. This transformation proceeds through a novel site-selective ring-opening of in situ-generated 2-sulfoxonium cyclobutanone by N-, O-, S-, and Se-centered nucleophiles. The reaction exhibits mild conditions, a broad substrate scope, and excellent scalability. Additionally, the resulting γ-sulfoxonium amides can undergo base-promoted intramolecular cyclization to afford γ-lactams, which are valuable scaffolds in medicinal chemistry.