Accessing Stable Magnesium Acyl Compounds: Reductive Cleavage of Esters by Magnesium(I) Dimers

Aaron J. Boutland, Carlos A. Lamsfus, Brant Maitland, Laurent Maron, Andreas Stasch, Cameron Jones

Research output: Contribution to journalArticleResearchpeer-review

4 Citations (Scopus)

Abstract

The first examples of magnesium acyls, [(Nacnac)Mg{μ-C(Ph)O}(μ-OR)Mg(Nacnac)] (R=Me, tBu or Ph; Nacnac=[HC(MeCNAr)2]; Ar=C6H2Me3-2,4,6 (MesNacnac), C6H3Et2-2,6 (DepNacnac), C6H3iPr2-2,6 (DipNacnac)), have been prepared by reductive cleavage of a series of esters using dimeric magnesium(I) reducing agents, [{(Nacnac)Mg}2]. Crystallographic studies reveal the complexes to be dimeric, being bridged by both phenyl-acyl and alkoxide/aryloxide fragments. The crystal structures, combined with results of spectroscopic and computational studies suggest that the nature of the acyl ligands within these complexes should be viewed as lying somewhere between anionic umpolung acyl and oxo-carbene. However, reactions of the acyl complexes with a variety of organic electrophiles did not provide evidence of umpolung acyl reactivity. A number of attempts to prepare alkoxide free magnesium acyls were carried out, and while these were unsuccessful, they did lead to unusual products, the crystallographic and spectroscopic details of which are discussed.

Original languageEnglish
Pages (from-to)14049-14055
Number of pages7
JournalChemistry - A European Journal
Volume23
Issue number56
DOIs
Publication statusPublished - 9 Oct 2017

Keywords

  • ester cleavage
  • magnesium acyl
  • magnesium(I)
  • reduction
  • umpolung

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