Aluminyl derived ethene functionalization with heteroallenes, leading to an intramolecular ligand rearrangement

The aluminacyclopropane K[Al(NON)(eta-C2H4)] ([NON]2- = [O(SiMe2NDipp)2]2-, Dipp = 2,6-iPr2C6H3) reacts with CO2 and iPrN00000000000000000000000000000000111111110000000011111111000000000000000000000000CNiPr to afford ring-expanded products of C-C bond formation. The latter system undergoes a 1,3-silyl retro-Brook rearrangement of the NON-group, to afford the [NNO]2- ligand ([NNO]2- = [N(Dipp)SiMe2N(Dipp)SiMe2O]2-). The mechanism of transformation was examined by density functional theory (DFT). Functionalization of ethene as a component of an aluminacyclopropane has been achieved using heteroallenes (CO2, carbodiimide). A spontaneous 'at metal' ligand rearrangement occurs which alleviates steric congestion at the Al centre.