Facile Reagent-Free Synthesis of Furo[3,2-c]pyridinones and Their Polynuclear Analogues with DDQ as Precursor

A variety of furo[3,2-c]pyridinones and their polynuclear analogues were achieved via a one-step oxidative cyclization using 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) as both the oxidant and the building block without auxiliary reagents under very mild conditions. The 4-hydroxylpyridinones, pyranones, and pyrimidinones are applicable in such transformations, demonstrating the astonishing generality of this furan assembly. This powerful protocol enables ready access to furan-fused heterocycles.