1. Metal-Organic Network Materials for Asymmetric Catalysis
Joseph M. Tanski, Department of Chemistry, Vassar College,
Poughkeepsie, NY 12604, USA
Matched pair asymmetric activation phenomena are a powerful approach to enhance enantioselectivity in existing catalytic systems. We have discovered that resolved titanium sec-butoxide, combined with resolved BINOL (BINOL = 1,1'-bi-2-naphthol) of the opposite configuration
designation, yields a dichiral matched pair that mediates the addition of dimethyl zinc to benzaldehyde with higher enantioselectivity than resolved BINOL with achiral Ti(OiPr)4 (40% ee) or the mismatched dichiral pair (40% ee).
Metal-Organic Network Materials prepared from titanium alkoxides and bis(hydroxyaryl) functionalized organic spacer ligands have been structurally characterized by X-ray crystallography, revealing that solvent donor ability influences the dimensionality of the materials obtained.
We are working on incorporating a chiral bidentate ligand inside of a porous network such that, when combined with resolved titanium sec-butoxide, the material will serve as an insoluble, recyclable, heterogeneous version of our dichiral catalyst.