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[摘要]:A series of chiral organocatalysts and Lewis acids have been evaluated in the Lewis acid/organocatalysts-based cooperative catalytic Biginelli reaction, which resulted in the determination of a novel cooperative Lewis acid/primary amine catalyst system, NbCl5/QN-NH2. The synergistic effect of NbCl5 and the quinine-derived primary amine is pronounced and gave dihydropyrimidiones (DHPMs) in moderate to good enantioselectivities (up to 84% ee) and good to excellent yields (up to 99% yield) under mild conditions. |
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