已开发出可回收的氟双功能金鸡纳生物碱/硫脲催化的四重氟化/ Michael / Michael / aldol序列,用于一锅合成带有六个连续立体中心(包括氟化叔碳)的环己醇。通过使用容易获得的原料,包括β-酮酸酯,β-硝基苯乙烯和α,β-不饱和醛,可以以52-80%的产率合成全功能化的环己醇,ee高达99%,dr > 20:1。氟固相萃取可以很容易地回收含氟催化剂,产率为94-97%,纯度> 98%。除了通过罐式经济反应实现高合成效率外,还采用了其他绿色技术,例如无过渡金属催化和催化剂回收。
Organocatalytic synthesis of quaternary stereocenter bearing a fluorine atom: enantioselective conjugate addition of α-fluoro-β-ketoesters to nitroalkenes
作者:Yeonock Oh、Sun Mi Kim、Dae Young Kim
DOI:10.1016/j.tetlet.2009.06.003
日期:2009.8
The catalytic enantioselective conjugateaddition reaction of α-fluoro-β-ketoesters to nitroalkenespromoted by chiral bifunctional organocatalysts is described. The treatment of α-fluoro-β-ketoesters with nitroalkenes under mild reaction conditions afforded the corresponding Michael adducts containing a fluorinated quaternary stereogenic center with excellent enantioselectivity (up to >99% ee).
Organocatalytic asymmetric synthesis of chiral fluorinated quaternary carbon containing β-ketoesters
作者:Hao Li、Shilei Zhang、Chenguang Yu、Xixi Song、Wei Wang
DOI:10.1039/b900777f
日期:——
of alpha-fluoroketoesters to nitroolefins efficiently catalyzed by a cinchona alkaloid-derivative affords versatile non-enolizable ketoesters by forming two consecutive fluorinated quaternary and tertiary chiralcarbon centers with excellent enantioselectivity.