Concise methods for the synthesis of chiral polyoxazolines and their application in asymmetric hydrosilylation.
Seven polyoxazoline ligands were synthesized in high yield in a one-pot reaction by heating polycarboxylic acids or their esters and chiral β-amino alcohols under reflux with concomitant removal of water or the alcohol produced in the reaction. The method is much simpler and more efficient in comparison to those methods reported in the literature.The compounds were used as chiral ligands in the rhodium-catalyzed asymmetric hydrosilylation of aromatic ketones, and the effects of the linkers and the substituents present on the oxazoline rings on the yield and enantioselectivity investigated. Compound 2 was identified as the best ligand of this family for the hydrosilylation of aromatic ketones.
Li
Wei Jie
WJ
Program for Natural Product Chemical Biology & Drug Discovery, South China Botanical Garden, Chinese Academy of Sciences, 723 Xingke Road, Tianhe District, Guangzhou 510650, China. weijieli1688@yahoo.com.cn
Xu
Zun Le
ZL
Qiu
Sheng Xiang
SX