Lewis acid-catalyzed enantioselective Friedel-Crafts reaction of pyrazole-4,5-diones with β-naphthol

A series of pyrazolone derivatives bearing a tetrasubstituted chiral center were prepared by virtue of a Lewis acid-catalyzed Friedel-Crafts reaction, in which a chiral copper complex was employed as the catalyst. This reaction can be carried out smoothly under mild condition to afford the pyrazolone derivatives with high yields (up to 85%) and excellent enantioselectivities (up to 99%). In addition, the gram scale synthesis proved the practicality of this reaction. (C) 2021 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Automated summary

A series of pyrazolone derivatives bearing a tetrasubstituted chiral center were successfully synthesized via a Lewis acid-catalyzed reaction using a chiral copper complex as the catalyst. The reaction proceeded smoothly under mild conditions, giving high yields (up to 85%) and excellent enantioselectivities (up to 99%). The gram scale synthesis also demonstrated the practicality of this reaction.