B(CF)-Catalyzed Decarboxylative Formation of Benzofurans via Intermolecular (3 + 2) Cyclization from Phenols.

We herein report unprecedented B(CF) catalyzed intermolecular (3 + 2) cyclizations enabling versatile construction of benzofurans from readily available methylene cyclic carbonates and phenols. Such an organocatalytic process tolerated well different functional groups and only generated water and CO as byproducts. The reactions proved to be scalable, and the corresponding products could be transformed into value-added benzofuran derivatives via simple experimental operations.