Dynamic kinetic resolution of racemic α-sulfonylaldehydes via asymmetric transfer hydrogenation
摘要:
Hydrogen transfer reduction of alpha-sulfonylaldehydes using HCOOH-Et3N system as hydrogen source and (S,S)-TsDPEN-based Ru(II) as catalyst proceeds with dynamic kinetic resolution, providing optically active p-sulfonyl primary alcohols in moderate-to-good yields and up to 90% ee. (c) 2008 Elsevier Ltd. All rights reserved.
Enantioselective S−H Insertion Reactions of α‐Carbonyl Sulfoxonium Ylides
作者:Patrícia B. Momo、Alexandria N. Leveille、Elliot H. E. Farrar、Matthew N. Grayson、Anita E. Mattson、Antonio C. B. Burtoloso
DOI:10.1002/anie.202005563
日期:2020.9
The first example of enantioselectiveS−Hinsertionreactions of sulfoxoniumylides is reported. Under the influence of thiourea catalysis, excellent levels of enantiocontrol (up to 95 % ee) and yields (up to 97 %) are achieved for 31 examples in S−Hinsertionreactions of aryl thiols and α‐carbonylsulfoxoniumylides.
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。
Asymmetric Carbon-Carbon Bond Formations by the Reaction of “Chiral Episulfonium Ions” with Enol Silyl Ethers
Carbonyl compounds having asymmetric carbon center at β position and phenylthio group on γ carbon were produced by the reaction of optically active 2-hydroxyalkyl phenyl sulfides with enolsilylethers in the presence of Lewis acid through “chiral episulfonium ions”.
Ritter-type substitution reaction of optically active β-hydroxyalkyl phenyl sulfides was found to proceed with retention fo configuration through the participation of phenylthio group to afford optically active amides.
Retention of configuration in the ritter-type substitution reaction of chiral β-arylthio alcohols through the anchimeric assistance of the arylthio group
作者:Akio Toshimitsu、Chitaru Hirosawa、Kohei Tamao
DOI:10.1016/s0040-4020(01)85367-9
日期:1994.1
In chiral alcohols bearing a phenylthio group at the β carbon atom. the hydroxy group is replaced by nitriles through the anchimericassistance of the phenylthio group to afford chiral amides with retention of configuration. This stereospecific Ritter-type reaction has been utilized in the conversion of chiral glycidol derivatives to chiral cyclic imino ethers such as oxazolines bearing an arylthio