C–H Metalation Reaction of Diarylamine and Carbazole by Alkylaluminum Complexes at the Heteroatom-Bridged Dimeric Aluminum Core



Direct metalation reactions of diphenylamine and carbazole by using an amido-bridged dinuclear Al2 complex proceeded across two aluminum atoms while maintaining the dinuclear structure. In contrast, an aryloxido-bridged dinuclear aluminium complex was inert to the C–H metalation reaction. Such different reactivity of the alkylaluminum complexes with an [Al2O2] or [Al2N2] core was attributed to the space available for the secondary amine substrates to approach the Al–Me moiety: the flexibility provided by the bridging amido ligand forms an Al2N2 core with both a planar and butterfly shape, which creates enough space for the Al–Me moiety to activate the amines.