Stepwise reduction of a base-stabilised ferrocenyl aluminium(iii) dihalide for the synthesis of structurally-diverse dialane species.

We report the reduction of bulky ferrocenyl-based NHC-stabilised aluminium(iii) diiodide [Fc*(NHC)AlI 2 ] (Fc* = 2,5-bis(3,5-di- tert -butylphenyl)-1-ferrocenyl) in different hydrocarbon solvents (hexane, benzene, toluene, and p -xylene), which results in different outcomes. Reduction in hexane with an equivalent amount of KC 8 generates the diiododialane [(Fc*(NHC)AlI) 2 ], whereas complete reduction in hexane leads to an unusual C-H activation at an N-Me group of one NHC unit. In contrast, reaction in aromatic solvents result in hitherto unknown Birch-type reductions of the corresponding solvent molecules by transient aluminium radicals of the type [LAlR 2 ]˙, which is ultimately bound to two aluminium centers.