Enantioselective synthesis of beta-(3-hydroxypyrazol-1-yl) ketones using an organocatalyzed Michael addition reaction.
Beta-(3-hydroxypyrazol-1-yl) ketones have been prepared in high yields and excellent enantioselectivities (94-98% ee) via a Michael addition reaction between 2-pyrazolin-5-ones and aliphatic acyclic alpha,beta-unsaturated ketones using 9-epi-9-amino-9-deoxyquinine as the catalyst. These results account for the first example of an aza-Michael addition of the ambident 2-pyrazolin-5-one anion to a Michael acceptor.
Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249-0698, USA.
Sanjib
S
Gogoi
Cong-Gui
CG
Zhao
Derong
D
Ding
D019817:Benzoic Acid / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D007659:Ketones / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D047069:Pyrazolones / Q000737:chemistry*; D013237:Stereoisomerism
D007659:Ketones; D047069:Pyrazolones; D019817:Benzoic Acid