Asymmetric direct aldol reaction of functionalized ketones catalyzed by amine organocatalysts based on bispidine.
Organocatalysts containing primary-secondary amine based on bispidine and amino acid have been designed to catalyze the asymmetric direct aldol reaction of functionalized ketones including alpha-keto phosphonates, alpha-keto esters, as well as alpha,alpha-dialkoxy ketones as aldol reaction acceptors. The corresponding products with chiral tertiary alcohols were obtained in moderate to high yields (up to 97%) and high enantioselectivities (up to 98% ee). A theoretical study of transition structures demonstrated that protonated piperidine was important for the reactivity and enantioselectivity of this reaction.
Liu
Jie
J
Key Laboratory of Green Chemistry & Technology, College of Chemistry, Sichuan University, Chengdu 610064, PR China.
Yang
Zhigang
Z
Wang
Zhen
Z
Wang
Fei
F
Chen
Xiaohong
X
Liu
Xiaohua
X
Feng
Xiaoming
X
Su
Zhishan
Z
Hu
Changwei
C