Novel bifunctional thiourea-ammonium salt catalysts derived from?amino acids: application to highly enantio- and diastereoselective aza-Henry reaction

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• 作者：Hong-Yu Wang^a ; Zhuo Chai^b ; Gang Zhao^a ; ^b ; ^{zhaog@mail.sioc.ac.cn}
• 关键词：Asymmetric catalysis ; Phase-transfer catalyst ; Amino acid ; Aza-Henry reaction ; Thiourea&ndash ; ammonium
• 刊名：Tetrahedron
• 出版年：2013
• 出版时间：24 June, 2013
• 年：2013
• 卷：69
• 期：25
• 页码：5104-5111
• 全文大小：736 K

文摘

The development of new efficient and easily accessible catalysts has been one of the focuses in asymmetric phase-transfer catalysis. In this paper, a novel class of chiral bifunctional thiourea-ammonium phase-transfer catalysts were synthesized from commercially available ¦Á-amino acids. The structural modularity of these catalysts permits facile tunings to achieve optimum results, which was demonstrated in catalyzing the aza-Henry reaction with excellent enantioselectivities (up to 99.5 % ee) and diastereoselectivities (up to >25:1 dr).