Catalytic Asymmetric Epoxidation of Aldehydes with Two VANOL-Derived Chiral Borate Catalysts
作者:Anil K. Gupta、Xiaopeng Yin、Munmun Mukherjee、Aman A. Desai、Aliakbar Mohammadlou、Kelsee Jurewicz、William D. Wulff
DOI:10.1002/anie.201809511
日期:2019.3.11
A highly diastereo‐ and enantioselective method for the epoxidation of aldehydes with α‐diazoacetamides has been developed with two different borate ester catalysts of VANOL. Both catalytic systems are general for aromatic, aliphatic, and acetylenic aldehydes, giving high yields and inductions for nearly all cases. One borate ester catalyst has two molecules of VANOL and the other only one VANOL. Catalysts
Storable and Air-Stable Zirconium Complex-Catalyzed Highly Enantioselective Darzens Reaction of Diazoacetamide with Aldehydes
作者:Long He、Wei-Jun Liu、Lei Ren、Tao Lei、Liu-Zhu Gong
DOI:10.1002/adsc.200900845
日期:——
An asymmetric Darzensreaction of aldehydes with diazo‐N,N‐dimethylacetamide (3) catalyzd by an air‐stable and storable chiral zirconium Lewis acid catalyst, which is formed from 3,3′‐diiodobinaphthol and tetrabutoxyzirconium, gives solely the cis‐glycidic amides in high yields with excellent enantioselectivity (up to 97% yield, >99% ee).