Highly enantioselective aldol reactions using a tropos dibenz[c,e]azepine organocatalyst

详细信息    查看全文

• 作者：Barry Lygo^a ;   ; ^{b.lygo@nottingham.ac.uk} ; Christopher Davison^a ; Timothy Evans^a ; James A.R. Gilks^a ; John Leonard^b ; Claude-Eric Roy^a
• 关键词：Asymmetric catalysis ; Aldol ; Organocatalysis ; Diamine ; Stereoselective
• 刊名：Tetrahedron
• 出版年：2011
• 出版时间：30 December 2011
• 年：2011
• 卷：67
• 期：52
• 页码：10164-10170
• 全文大小：569 K

文摘

The four-step synthesis of a chiral primary tertiary diamine salt, possessing a tropos dibenz[c,e]azepine ring is described. It is shown that 3.5??mol? % of this salt is capable of promoting highly enantioselective crossed-aldol reactions between cyclohexanone and a series of aromatic aldehydes. In all cases, the aldol reactions proceed with high diastereoselectivity for the anti-aldol product. The outcome of crossed-aldol reactions involving other cyclic ketones and acyclic ketones are also described. All examples involving cyclic ketones result in selectivity for the anti-aldol products, whereas acyclic ketones were found to favour the syn-aldol products. A discussion on the role of the chiral primary tertiary diamine salt in the catalysis of the aldol reactions is also presented.