Asymmetric direct aldol reaction catalyzed by an L-prolinamide derivative: considerable improvement of the catalytic efficiency in the ionic liquid.
The asymmetric direct aldol reactions of a wide scope of aldehydes with unmodified ketones in the presence of 20 mol%(S,S,S)-pyrrolidine-2-carboxylic acid (2'-hydroxyl-1',2'-diphenyl-ethyl)-amine (1) were performed in ionic liquids; aldol products with 91 to >99% ees for aromatic aldehydes and 99% ees for alphatic aldehydes were offered by the present procedure.
Guo
Hai-Ming
HM
Key Laboratory for Asymmetric Synthesis and Chirotechnology of Sichuan Province and Union Laboratory of Asymmetric Synthesis, Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, 610041, China.
Cun
Lin-Feng
LF
Gong
Liu-Zhu
LZ
Mi
Ai-Qiao
AQ
Jiang
Yao-Zhong
YZ