The regioselectivity observed in the intramolecular palladium-catalyzed arylation of substituted bromobenzyldiarylmethanes as well as theoretical results demonstrate that the Pd-catalyzed arylation proceeds by a mechanism involving a proton abstraction by the carbonate, or a related basic ligand. The reaction is facilitated by electron-withdrawing substituents on the aromatic ring, which is inconsistent with an electrophilic aromatic-substitution mechanism. The more important directing effect is exerted by electron-withdrawing substituents ortho to the reacting site. © 2007 American Chemical Society.
García-Cuadrado, D., De Mendoza, P., Braga, A. A. C., Maseras, F., & Echavarren, A. M. (2007). Proton-abstraction mechanism in the palladium-catalyzed intramolecular arylation: Substituent effects. Journal of the American Chemical Society, 129(21), 6880-6886. https://doi.org/10.1021/ja071034a