Cross-dehydrogenative coupling enables enantioselective access to CF₃-substituted all-carbon quaternary stereocenters

A cross-dehydrogenative coupling strategy for enantioselective access to acyclic CF₃-substituted all-carbon quaternary stereocenters has been established. By using catalytic DDQ with MnO₂ as an inexpensive terminal oxidant, asymmetric cross coupling of racemic δ-CF₃-substituted phenols with indoles proceeded smoothly, providing CF₃-bearing all-carbon quaternary stereocenters with excellent chemo- and enantioselectivities. The generality of the strategy is further demonstrated by efficient construction of all-carbon quaternary stereocenters bearing other polyfluoroalkyl and perfluoroalkyl groups such as CF₂Cl, C₂F₅, and C₃F₇.