A highly efficient α-hydroxylation of β-ketoesters catalyzed by cupreidine in the presence of cumyl hydroperoxide (CHP) was achieved. The reaction was applied to a wide variety of β-ketoesters to give products in high yields (up to 95%) with excellent enantioselectivities (up to 97% ee). The reaction had been successfully scaled up to a gram quantity and (S)-5-chloro-2-hydroxy-1-oxo-2,3-dihydro-
asymmetric α‐hydroxylation of β‐indanone esters and β‐indanone amides using peroxide as the oxidant was realized with a new C‐2′ substituted Cinchona alkaloid derivatives. The two enantiomers of α‐hydroxy‐β‐indanone esters could be obtained by simply changing the oxidant. This protocol allows a convenient access to the corresponding α‐hydroxy‐β‐indanone esters and α‐hydroxy‐β‐indanone amides with up to
Scheme 1. Diterpenoidalkaloidlappaconine and preparation of lappaconinederivatives.[a] State Key Laboratory of Fine ChemicalsSchool of Pharmaceutical Science and TechnologyDalian University of TechnologyNo. 2 Linggong Road, Ganjingzi District, Dalian, LiaoningProvince 116012, P. R. ChinaE-mail: mengqw@dlut.edu.cnhttp://ceb.dlut.edu.cn/index.html[b] Department of Pharmaceutics, Daqing CampusHarbin
Zirconium‐Salan Catalyzed Enantioselective
<i>α</i>
‐Hydroxylation of
<i>β</i>
‐Keto Esters
作者:Jie Chen、Haiyang Gu、Xueying Zhu、Wonwoo Nam、Bin Wang
DOI:10.1002/adsc.202000290
日期:2020.7.29
C2‐symmetric salan ligands and cumene hydroperoxide as an oxidant, affording synthetically valuable hydroxylation products in high yields (up to 99%) with excellent enantioselectivities (up to 99% ee) under mild reaction conditions. In mechanistic studies, we have shown that (1) a Zr(IV)‐salan complex was generated in situ as the active catalyst responsible for the chiralinduction, (2) the transfer