The metal-hydrogen exchange reaction (metallation) is one of the most fundamental synthetic tools. Traditionally, bases such as lithium alkyls have been used for the deprotonative metallation of aromatic rings; however, their high nucleophilicity restrict their use with certain sensitive functional groups.
Professor Mulvey's group have shown that special synergic effects can be induced by mixing an alkali metal base with certain magnesium or zinc reagents, leading to revolutionary new mixed-metal reagents that can perform reactions impossible with traditional single metal reagents; introducing the new concepts of alkali-metal-mediated magnesiation (AMMM) and alkali-metal-mediated zincation (AMMZ). For example, toluene can be regioselectively twofold deprotonated at the 2,5-ring positions in a reaction with a mixed-metal Na/Mg compound, that is outside the scope of conventional organometallic bases, which generally attack the more acidic Me group. Recently, this novel chemistry has been extended to a transition metal (manganese) thus pioneering the idea of alkali-metal-mediated manganation (AMMMn).