DOI: 10.1055/a-2307-0645 ISSN: 0936-5214
Tripeptide-Catalyzed Asymmetric Michael Addition Reaction of β-Nitrostyrenes with Cyclohexanone
Kippei Maeda, Mitsuki Takeyama, Yoshihito Kohari, Miki Murata- Organic Chemistry
A tripeptide catalyst derived from natural L-amino acids was employed in the reaction of β-nitrostyrenes with cyclohexanone, serving as a model for the asymmetric Michael addition reaction. The reaction was conducted in the presence of H-Pro-Tle-Gly-OH and 2-Fluoro-4-ChloroBenzoic acid as co-catalysts (each at 20 mol%) in DMF-H2O (5:1) at 0℃ for 3 days. This process yielded the desired Michael adducts with excellent efficiency and good stereoselectivity (up to 98% yield, up to 92%ee).