Reversible, Room-Temperature CC Bond Activation of Benzene by an Isolable Metal Complex

The
activation of CC bonds is of fundamental interest in
the construction of complex molecules from petrochemical feedstocks.
In the case of the archetypal aromatic hydrocarbon benzene, CC
cleavage is thermodynamically disfavored, and is brought about only
by transient highly reactive species generated in situ. Here we show that the oxidative addition of the CC bond
in benzene by an isolated metal complex is not only possible, but
occurs at room temperature and reversibly at a single aluminium center
in [(NON)­Al]− (where NON = 4,5-bis­(2,6-diisopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene). Selectivity over CH
bond activation is achieved kinetically and allows for the generation
of functionalized acyclic products from benzene.