Jump to main content
Jump to site search

Issue 29, 2012
Previous Article Next Article

Stereospecific synthesis and catalytic activity of L-histidylidene metal complexes

Author affiliations

Abstract

We report on the synthesis, metal coordination, and catalytic impact of histidylidene, a histidine-derived N-heterocyclic carbene (NHC) ligand. The histidinium salt 3, comprising methyl substituents at both heterocyclic nitrogens and protected at the C- and N-terminus of the amino acid, was rhodated and iridated by a transmetallation protocol using Ag2O. Ambient temperature and short reaction times were pivotal for full retention of configuration at the α-carbon. The stereospecificity of the reaction was conveniently probed by 31P NMR spectroscopy after transmetallation with rhodium(I) and coordination of enantiopure (S)-Ph-binepine. The histidylidene rhodium complexes are highly efficient catalysts for the mild hydrosilylation of ketones. For the cationic complexes [Rh(cod)(histidylidene)(phosphine)]+, lowering the temperature shifted the rate-limiting step of the catalytic reaction to an earlier stage that is not enantioselective. Hence the asymmetric induction—which is governed by the chiral phosphine—did not improve at low temperature.

Graphical abstract: Stereospecific synthesis and catalytic activity of l-histidylidene metal complexes

Back to tab navigation

Supplementary files

Publication details

The article was received on 13 Apr 2012, accepted on 16 May 2012 and first published on 16 May 2012


Article type: Paper
DOI: 10.1039/C2DT30799E
Citation: Dalton Trans., 2012,41, 8813-8821
  •   Request permissions

    Stereospecific synthesis and catalytic activity of L-histidylidene metal complexes

    A. Monney, E. Alberico, Y. Ortin, H. Müller-Bunz, S. Gladiali and M. Albrecht, Dalton Trans., 2012, 41, 8813
    DOI: 10.1039/C2DT30799E

Search articles by author

Spotlight

Advertisements