Synthesis of gem‐Difluorinated Isoxazoles via Palladium‐Catalyzed Oxylallylation of Alkynone Oxime Ethers

Abstract A novel and reliable palladium‐catalyzed oxylallylation of alkynone oxime ethers with fluorine‐containing alkenes was accomplished. Using the bulk industrial chemical 3‐bromo‐3,3‐difluoroprop‐1‐ene as the coupling partner, this synthetic methodology offers the first example for the assembly of structurally diverse gem ‐difluorinated isoxazole derivatives in moderate to good yields with high atom‐ and step‐economy and excellent functional group compatibility. More importantly, this strategy allows for the direct combination of the isoxazole motifs and gem ‐difluoroalkene unit, which is not easy to obtain through a general synthetic strategy.