%0 Journal Article
%T Primary amine-catalyzed enantioselective 1,4-Michael addition reaction of pyrazolin-5-ones to α,β-unsaturated ketones.
%A Goyal P
%A Dubey AK
%A Chowdhury R
%A Wadawale A
%J Beilstein J Org Chem
%V 20
%N 0
%D 2024
%M 39015621
%F 2.544
%R 10.3762/bjoc.20.136
%X The enantioselective 1,4-addition reaction of pyrazolin-5-ones to α,β-unsaturated ketones catalyzed by a cinchona alkaloid-derived primary amine-Brønsted acid composite is reported. Both enantiomers of the anticipated pyrazole derivatives were obtained in good to excellent yields (up to 97%) and high enantioselectivities (up to 98.5% ee) under mild reaction conditions. In addition, this protocol was further expanded to synthesize highly enantioenriched hybrid molecules bearing biologically relevant heterocycles.