text: Reaction systems that are less efficient or entirely inactive in the absence of carboxylate acids and bases are likely to occur through a concerted metalation protonation reaction pathway. An example of such a reaction with an sp C–H bond that was reported in 2007 by Keith Fagnou and coworkers is an intramolecular cyclization that uses a palladium catalyst.
  A notable example of a reaction that is catalyzed by ruthenium in which directed metalation occurs through CMD was reported by Igor Larossa and coworkers in 2018. The ruthenium catalyst is functional group tolerant and enables the late stage synthesis of pharmaceutically relevant biaryls.