Highly diastereo- and enantioselective direct aldol reaction under solvent-free conditions

作者：Zhang Furen; Li Chunmei; Qi Chenze^*

来源：Tetrahedron: Asymmetry , 2013, 24(7): 380-388.

DOI：10.1016/j.tetasy.2013.02.013

An efficient, solvent-free protocol for the asymmetric aldol reaction between aldehydes and ketones using prolinamides 1-4 as organocatalysts is reported. Catalysts 2-4, in the presence of TFA (the ratio of catalyst and TFA = 1/1.5), proved to be excellent catalysts, giving the aldol products between aromatic aldehydes and ketones with nearly perfect diastereo- and enantioselectivities (up to >99:1 dr and >99% ee). This catalytic system can also be applied in the cross-aldol reaction of isatin with ketones and the Michael reaction between cyclohexane and nitroalkenes. A mechanism is proposed to account for the formation of the major enantiomer in this reaction.

• 出版日期2013-4-15
• 单位绍兴文理学院