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

作者：Lygo Barry^*; Davison Christopher; Evans Timothy; Gilks James A R; Leonard John; Roy Claude Eric

来源：Tetrahedron, 2011, 67(52): 10164-10170.

DOI：10.1016/j.tet.2011.09.101

• Asymmetric catalysis
• Aldol
• Organocatalysis
• Diamine
• Stereoselective

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 3.5-5 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.

• 出版日期2011-12-30