Iodine-Catalyzed Construction of Dihydrooxepines via 3-Methyl-5-Pyrazolones C−H Oxidation/Functionalization of Quinolines Cascade

An efficient iodine-catalyzed [3+3+1] annulation for the construction of dihydrooxepine scaffolds with quinoline units was developed. This strategy involves a seven-membered dihydrooxepine with a broad substrate scope through a formal three-component tandem reaction. Further derivation of the target product produced a trioxabicycle scaffold, which formed the basic core of natural products and pharmaceutical molecules.