Synthesis of Substituted Chiral Pyrrolidine and Its Catalytic Michael Reaction
Two chiral pyrrolidine organic catalysts with multiple hydrogen bonds and active centers were designed and synthesized,(S)-2-hy-droxy-N-(pyrrolidine-2-methylene)benzamide(1a)and(S)-3-hydroxy-N-(pyrrolidine-2-methylene)-2-naphthamide(1b),for the Michael addition reaction of pyrazolone and nitroene.Research has shown that pyrazole-5-ol derivatives synthesized using di-chloromethane as a solvent and 20 mol%1a as a catalyst at room temperature(25 ℃)exhibit good yields(90%)and high enantioselectivity(97%).This method provides an important pathway for constructing intermediates with biological pharmacological activity for carbon carbon bond synthesis.