Abstract
Enantioselective organocatalytic Michael additions serve as the key step in syntheses of chiral drugs based on γ-aminobutyric acid. The applicability of various squaramide catalysts for these Michael-type reactions has been assessed. Very good results in terms both activity and enantioselectivity were obtained in the Michael addition of dimethyl malonate to β-nitrostyrenes. On the other hand, a complementary approach, the addition of nitromethane to cinnamaldehydes, worked well with a squaramide catalyst possessing an adjacent pyrrolidine moiety. The corresponding Michael adducts obtained in the best conditions are suitable chiral intermediates for the synthesis of therapeutically useful GABA derivatives. Polymer-immobilized squaramides afforded the Michael adduct in high enantiomeric purity, but yield deterioration was observed between runs. Two different formal total syntheses of baclofen have also been accomplished.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.