Umpolung of an Aliphatic Ketone to a Magnesium Ketone‐1,2‐diide Complex with Vicinal Dianionic Charge

The new β-diketimine iPrDipnacnacH, HC(iPrCNDip)2H, Dip=2,6-iPr2-C6H3, was converted to the magnesium(I) complex [{(iPrDipnacnac)Mg}2] and reaction with 2-adamantanone (OAd) afforded ketone-1,2-diide [{(iPrDipnacnac)Mg}2(μ-OAd)]. contains first stable dianion of an aliphatic ketone electropositive metal shows OAd2− unit long C−O bond pyramidal carbon centre. DFT studies reveal anionic charge on both neighbouring C O atoms. Reductions ketones complexes show that these likely proceed via highly reactive dianions a 1 : mixture alkoxide enolate when enolisable used, rapid CH activations reactions, e.g., stabilising ligand moieties, non-enolisable were employed.