Synthesis of dibenzopyranones and pyrazolobenzopyranones through copper(0)/Selectfluor system-catalyzed double CH activation/oxygen insertion of 2-arylbenzaldehydes and 5-arylpyrazole-4-carbaldehydes
A mild and efficient protocol for the synthesis of dibenzopyranones and pyrazolobenzopyranones was developed involving a copper(0)/Selectfluor system-catalyzed double CH activation/oxygen insertion of 2-arylbenzaldehydes and 5-arylpyrazole-4-carbaldehydes. Preliminary mechanistic studies suggest that both water and dioxygen act as the oxygen source in the formation of pyranone scaffolds.