Nucleophilic Isomerization of Epoxides by Pincer‐Rhodium Catalysts: Activity Increase and Mechanistic Insights

Herein, we present the efficient isomerization of epoxides into methyl ketones with a novel pincer‐rhodium complex under very mild conditions. The catalyst system has an excellent functional group tolerance and a wide array of epoxides was tested. The corresponding methyl ketones were obtained in very high yields with excellent chemo‐ and regioselectivity. In addition, we investigated mechanistic details like the isomerization of the catalyst, and we obtained evidence that the catalytic cycle follows a β‐hydride elimination‐reductive elimination pathway after the nucleophilic ring opening of the epoxide. Finding the path: The efficient isomerization of a wide range of epoxides into methyl ketones is achieved using a novel pincer‐rhodium complex under very mild conditions with excellent chemo‐ and regioselectivity. Investigations on the mechanism reveal the concomitant isomerization of the catalyst and provide evidence for a β‐hydride elimination‐reductive elimination step in the catalytic cycle.