Ruthenium-catalyzed room-temperature coupling of α-keto sulfoxonium ylides and cyclopropanols for δ-diketone synthesis

Previous transition metal-catalyzed synthesis processes of delta-diketones are plagued by the high cost of the rhodium catalyst and harsh reaction conditions. Herein a low-cost, room temperature ruthenium catalytic method is developed based on the coupling of alpha-keto sulfoxonium ylides with cyclopropanols. The mild protocol features a broad substrate scope (47 examples) and a high product yield (up to 99%). Mechanistic studies argue against a radical pathway and support a cyclopropanol ring opening, sulfoxonium ylide-derived carbenoid formation, migratory insertion C-C bond formation pathway.

Automated summary

A low-cost, room temperature ruthenium catalytic method was developed for the synthesis of delta-diketones by coupling alpha-keto sulfoxonium ylides with cyclopropanols. The mild protocol showed a broad substrate scope (47 examples) and high product yield (up to 99%), with mechanistic studies supporting a cyclopropanol ring opening, sulfoxonium ylide-derived carbenoid formation, migratory insertion C-C bond formation pathway.