Lewis Acid-Promoted Three-Component Cyclization for the Construction of Functionalized Oxazoles

A simple and efficient synthetic strategy from amides, ynals, and sodium sulfinates via a Lewis acid-promoted three-component reaction has been reported. Thus, a broad range of various aryl (not alkyl)-substituted oxazoles could be synthesized via the formation of C–N, C–O, and C–S bonds in a one-pot process. In addition, this reaction possesses other unique advantages, such as transition metal-free catalysis, high step economy, good functional group tolerance, and good regioselectivity.