Mechanistic Switch via Subtle Ligand Modulation: Palladium-Catalyzed Synthesis of α,β-Substituted Styrenes via C-H Bond Functionalization

A new catalyst system able to efficiently perform the synthesis of styrenes via C-H bond functionalization and a subtle ligand modification are described. The high level of activity achieved allows for the synthesis of highly functionalized alpha,beta-substituted styrenes, even the elusive E-configured trisubstituted olefins, in a regio- and stereoselective manner. Mechanistic experiments allowed for the identification of the corresponding synthetic intermediates.