Enhancing the Nucleophilicity of Aluminyl Anions: Targeting Selective C–H Activation

Anionic aluminium(I) complexes, or aluminyl anions, are a recently discovered class of main group compounds that can C–H activate simple aromatic molecules. However, functional group tolerance remains an issue, with the activation of functionalised arenes often favouring more kinetically accessible side reactions (e.g. C–O/C–F activation) over the desired C–H activation. Here, we report a new, electron-rich potassium aluminyl complex, which by DFT has been calculated to be the most nucleophilic diamido aluminyl anion reported to date. The anion shows unprecedented rates of reaction towards the C–H activation of arenes, achieving the C–H activation of stoichiometric benzene in seconds at room temperature. Furthermore, the C–H activation is selective even in a range of functionalised arenes, including those with C–O and C–F bonds.