Potassium Aluminyl Promoted Carbonylation of Ethene.

The potassium aluminyl [K{Al(NON Dipp )}] 2 ([NON Dipp ] 2- =[O{SiMe 2 NDipp} 2 ] 2- , Dipp=2,6-iPr 2 C 6 H 3 ) activates ethene towards carbonylation with CO under mild conditions. An isolated bis-aluminacyclopropane compound reacted with CO via carbonylation of an Al-C bond, followed by an intramolecular hydrogen shift to form K 2 [Al(NON Dipp )(μ-CH 2 CH=CO-1κ 2 C 1,3 -2κO)Al(NON Dipp )Et]. Restricting the chemistry to a mono-aluminium system allowed isolation of [Al(NON Dipp )(CH 2 CH 2 CO-κ 2 C 1,3 )] - , which undergoes thermal isomerisation to form the [Al(NON Dipp )(CH 2 CH=CHO-κ 2 C,O)] - anion. DFT calculations highlight the stabilising influence of incorporated benzene at multiple steps in the reaction pathways.