A Stable Calcium Alumanyl

A seven‐membered N,N′‐heterocyclic potassium alumanyl nucleophile is introduced and utilised in the metathetical synthesis of Mg−Al and Ca−Al bonded derivatives. Both species have been characterised by experimental and theoretical means, allowing a rationalisation of the greater reactivity of the heavier group 2 species implied by an initial assay of their reactivity. AlCan Wrap: The Reaction of a seven‐membered cyclic alumanyl anion with a β‐diketiminato calcium tetraphenylborate provides facile access to a stable, but highly reactive, calcium alumanyl.