Asymmetric [2 + 2] cycloaddition reaction catalyzed by a chiral titanium reagent
摘要:
In the presence of certain Lewis acids, alkenes containing an alkylthio group (for example, ketene dithioacetals, alkenyl sulfides, alkynyl sulfides, and allenyl sulfides) react with electron deficient olefins to give the corresponding cyclobutane, cyclobutene, or methylene cyclobutane derivatives. By employing a chiral titanium catalyst generated in situ from dichlorodiisopropoxytitanium and a tartrate-derived chiral diol, the [2 + 2] cycloaddition reaction proceeds with high enantioselectivity.
Asymmetric [2+2] Cycloaddition Reaction between α,β-Unsaturated Acid Derivatives and Alkynyl or Alkenyl Sulfides Catalyzed by a Chiral Titanium Reagent
作者:Yujiro Hayashi、Koichi Narasaka
DOI:10.1246/cl.1990.1295
日期:1990.8
Asymmetric [2+2] cycloaddition reaction between 3-(acryloyl)-1,3-oxazolidin-2-one derivatives and alkynyl or alkenyl sulfides proceeds by the use of a chiral titanium reagent to give the corresponding cyclobutene or cyclobutane derivatives in high enantioselectivity.