β,β-Difluoro Peroxides as Fluorinated C2-Building Blocks for the Construction of Functionalized Indolizines

An effective method for the construction of functionalized indolizines has been developed in which β,β-difluoro peroxides act as novel C2-building blocks to implement [3+2] annulation with pyridinium ylides under base-mediated conditions. With this protocol, a broad range of multisubstituted indolizines were prepared in moderate to good yields under mild conditions, and many useful functional groups were tolerated.