Secondary Alkyl Halides in Transition‐Metal‐Catalyzed Cross‐Coupling Reactions

Secondary, but second to none : The use of secondary alkyl halides in transition‐metal‐catalyzed cross‐coupling reactions (see scheme) has advanced significantly over the last five years. Selected examples of these transformations are examined, including mechanistic and stereochemical aspects. magnified image Enormous effort has gone into the development of metal‐catalyzed cross‐coupling reactions with alkyl halides as electrophilic coupling partners. Whereas a wide array of primary alkyl halides can now be used effectively in cross‐coupling reactions, the synthetic potential of secondary alkyl halides is just beginning to be revealed. This Minireview summarizes selected examples of the use of secondary alkyl halides as electrophiles in cross‐coupling reactions. Emphasis is placed on the transition metals employed, the mechanistic pathways involved, and implications in terms of the stereochemical outcome of reactions.