Highly Enantioselective Reactions of Configurationally Labile α-Thioorganolithiums Using Chiral Bis(oxazoline)s via Two Different Enantiodetermining Steps
that the reaction of α-lithio benzyl phenyl sulfide proceeds through a dynamic kinetic resolutionpathway. The enantioselectivereactions of α-lithio benzyl 2-pyridyl sulfide gave the products with stereochemistry reverse to that obtained in the reaction of benzyl phenyl sulfide. We confirmed that this reaction proceeds through a dynamic thermodynamicresolutionpathway in which the reaction with an
α-甲锡烷基苯硫醚的异丙苯溶液在 -78 °C 下用 n-BuLi 和双(恶唑啉)-iPr 处理,随后用二苯甲酮处理,得到 99% ee 的产物。我们证实α-锂硫苄基苯硫醚的反应通过动态动力学拆分途径进行。α-锂硫苄基2-吡啶基硫醚的对映选择性反应得到的产物与苄基苯基硫醚反应得到的产物立体化学相反。我们证实该反应通过动态热力学拆分途径进行,在该途径中,与亲电子试剂的反应比非对映体复合物之间的相互转化进行得更快。
Ligand coupling through σ-sulfurane — complete retention of configuration of 1-phenylethyl group in the reaction of 1-phenylethyl 2-pyridyl sulfoxide with grignard reagent1
作者:Shigeru Oae、Tsutomu Kawai、Naomichi Furukawa
DOI:10.1016/s0040-4039(01)91150-5
日期:1984.1
The reaction of benzyl or 1-phenylethyl 2-pyridyl sulfoxide with Grignard reagent proceeds via a σ-sulfurane as an intermediate to give the coupling product, 2-benzylpyridine or 2-(1-phenylethyl)pyridine in quantitative yield. Stereochemistry for this reaction is complete retention at the benzylic carbon atom.