Cooperative and Enantioselective NbCl5/Primary Amine Catalyzed Biginelli Reaction

✍ Scribed by Yong-Feng Cai; Hua-Meng Yang; Li Li; Ke-Zhi Jiang; Guo-Qiao Lai; Jian-Xiong Jiang; Li-Wen Xu

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 375 KB
• Volume: 2010
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/ejoc.201000894

✦ Synopsis

Abstract

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, NbCl~5~/QN‐NH~2~. The synergistic effect of NbCl~5~ 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.