Wasserstoff/Deuterium-Isotopeneffekte bei Europium-Verschiebungsexperimenten and Allencarbonsäureestern
作者:Robert W. Lang、Hans-Jürgen Hansen
DOI:10.1002/hlca.19800630513
日期:1980.7.9
Hydrogen/Deuterium Isotope Effects on Europium Induced Chemical Shifts of Allenic Esters
氢/氘同位素对Euro诱导的烯丙基酯化学位移的影响
Asymmetric Olefin Isomerization of Butenolides via Proton Transfer Catalysis by an Organic Molecule
作者:Yongwei Wu、Ravi P. Singh、Li Deng
DOI:10.1021/ja205674x
日期:2011.8.17
general olefin isomerization was realized via biomimetic protontransfer catalysis with a new chiral organic catalyst. A broad range of mono- and disubstituted β,γ-unsaturated butenolides were transformed into the corresponding chiral α,β-unsaturated butenolides in high enantioselectivity and yield in the presence of as low as 0.5 mol % catalyst. Mechanistic studies have revealed the protonation as the