anti-Selective catalytic asymmetric nitroaldol reaction via a heterobimetallic heterogeneous catalyst

J Am Chem Soc. 2009 Sep 30;131(38):13860-9. doi: 10.1021/ja905885z.

Abstract

Full details of an anti-selective catalytic asymmetric nitroaldol reaction promoted by a heterobimetallic catalyst comprised of Nd(5)O(O(i)Pr)(13), an amide-based ligand, and NaHMDS (sodium hexamethyldisilazide) are described. A systematic synthesis and evaluation of amide-based ligands led to the identification of optimum ligand 1m, which provided a suitable platform for the Nd/Na heterobimetallic complex. During the catalyst preparation in THF, a heterogeneous mixture developed and centrifugation of the suspension allowed for separation of the precipitate, which contained the active catalyst and which could be stored for at least 1 month without any loss of catalytic performance. The precipitate promoted a nitroaldol (Henry) reaction for a broad range of nitroalkanes and aldehydes under heterogeneous conditions, affording the corresponding 1,2-nitroalkanol in a highly anti-selective (up to anti/syn = >40/1) and enantioselective manner (up to 98% ee). Inductively coupled plasma (ICP) and X-ray fluorescence (XRF) analyses revealed that the precipitate indeed included both neodymium and sodium, which was further supported by high-resolution ESI TOF MS spectrometry.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aldehydes / chemical synthesis*
  • Alkanes / chemical synthesis*
  • Catalysis
  • Organosilicon Compounds / chemistry*
  • Spectrometry, Mass, Electrospray Ionization

Substances

  • Aldehydes
  • Alkanes
  • Organosilicon Compounds
  • 3-hydroxybutanal
  • hexamethylsilazane