Burnett S, Bourne C, Slawin AMZ, van Mourik T, Stasch A. Umpolung of an Aliphatic Ketone to a Magnesium Ketone‐1,2‐diide Complex with Vicinal Dianionic Charge.
Angew Chem Int Ed Engl 2022;
61:e202204472. [PMID:
35762819 PMCID:
PMC9541192 DOI:
10.1002/anie.202204472]
[Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Indexed: 12/05/2022]
Abstract
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 the ketone‐1,2‐diide complex [{(iPrDipnacnac)Mg}2(μ‐OAd)]. The complex contains the first stable dianion of an aliphatic ketone with an electropositive metal and shows an OAd2− unit with long C−O bond and pyramidal carbon centre. DFT studies reveal an anionic charge on both neighbouring C and O atoms. Reductions of aliphatic ketones with magnesium(I) complexes show that these likely proceed via highly reactive dianions and afforded a 1 : 1 mixture of an alkoxide and an enolate when an enolisable ketone was used, and rapid CH activations reactions, e.g., of stabilising ligand moieties, when non‐enolisable ketones were employed.
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