The Regiocontrollable Enantioselective Synthesis of Chiral Trifluoromethyl-Containing Spiro-Pyrrolidine-Pyrazolone Compounds via Amino-Regulated 1,3-Proton Migration Reaction
Yabo Deng, Zhenghao Dong, Fengyun Gao, Yifei Guo, Mengmeng Sun, Yongzhen Li, Yalan Wang, Qushuo Chen, Kairong Wang, Wenjin Yan
Abstract
-containing spiro-pyrrolidine-pyrazolone compounds is described. With alkaloid-derived squaramide as catalyst, the 1,3-dipolar cycloaddition of α,β-unsaturated pyrazolone with diethyl 2-((2,2,2-trifluoroethyl)imino) malonate offered adducts in excellent yields, dr, and ee. While the cyclohexanediamine-derived squaramide was employed, the reaction afforded a series of structure isomers through a switched umpolung reaction.
Topics & Concepts
ChemistrySquaramideEnantioselective synthesisPyrrolidineDiethyl malonateStereocenterPyrazoloneAldol reactionCycloadditionMichael reactionTrifluoromethylMalonateOrganocatalysisMedicinal chemistryOrganic chemistryCatalysisStereochemistryAlkylFluorine in Organic ChemistryAsymmetric Synthesis and CatalysisSynthesis and Catalytic Reactions