The palladium-catalyzed direct arylation of 3-(indol-3-yl)propionic acids with aryl bromides proceeds through C H bond cleavages to give C2-arylated product in good yields. The C2-alkenylation of the substrates can also be performed smoothly under appropriate oxidative conditions.
Harley-Mason, Journal of the Chemical Society, 1952, p. 2433