1. b-Hydroxysalicylhydrazones: Chiral, non-racemic tridentate catalysts for asymmetric synthesis
Shawn R. Hitchcock, Department of Chemistry, Illinois State University, Normal, IL
My research program has been focused on the design, synthesis, and application of chiral hydrazones as tools for conducting asymmetric synthesis via the 1,2-addition of diethylzinc to aldehydes. We have been able to create a variety of derivatives based on the b-hydroxysalicylhydrazone motif that was developed by my group. These hydrazones afforded enantioselectivities in the asymmetric addition reaction that ranged from 13 to 68%ee.
The salicylhydrazone chemistry led to our research with ligands that were easier to prepare and offered and an opportunities to study factors contributing to obtaining improved enantioselectivities.
We learned that these easily prepared Ephedra derivatives could indeed serve as effective ligands in the asymmetric addition reaction and this has inspired our current work with the palladium catalyzed asymmetric allylic alkylation of dimethyl malonate . Our current efforts are now directed towards using the Ephedra alkaloids and other chiral, non-racemic b-amino alcohols.