Highly enantioselective routes to darzens and acetate aldol products from achiral aldehydes and t-butyl bromoacetate
摘要:
New methodology is described for the enantioselective coupling of t-butyl bromoacetate with aldehydes to give anti-alpha-bromo beta-hydroxy esters (1), useful precursors of chiral glycidic esters (2), acetate aldols (3), beta-amino acid esters (4) and alpha-amino acid esters (5).
[2.2]Paracyclophane-based carbene–copper catalyst tuned by transannular electronic effects for asymmetric boration
作者:Jianqiang Chen、Wenzeng Duan、Zhen Chen、Manyuan Ma、Chun Song、Yudao Ma
DOI:10.1039/c6ra14404g
日期:——
of planar chiral carbene–copper complexes based on the [2.2]paracyclophane backbone with a pseudo-ortho substitution pattern have been synthesized and applied to asymmetric β-boration of α,β-unsaturatedesters. As a result, transannular electronic effects of the substituent of the chiralcatalyst have significant influence on the catalytic performance. A variety of chiral β-hydroxyl esters were obtained