Diastereoselective Intramolecular Ester Transfer Reaction of<i>N</i>-Alkenylcarbamate Derivatives Mediated by Zirconocene-Butene Complex: Preparation of α,γ-Disubstituted γ-Aminobutyric Acid (GABA) Derivatives and 2,4-Disubstituted Pyrrolidine Derivatives
作者:Takeo Taguchi、Yasushi Takigawa、Hisanaka Ito、Katsunori Omodera、Minoru Koura、Yasuyuki Kai、Emi Yoshida
DOI:10.1055/s-2005-870027
日期:——
Zirconium-mediated diastereoselective alkene-carbonyl coupling reactions of N-alkenylcarbamate derivatives are reported. The present alkene-carbonyl coupling reactions using chiral tert-butyl 3-butenylcarbamates having a substituent at the homoallylic position proceeded in a highly diastereoselective manner to give α-methyl-γ-substituted γ-aminobutyric acid (GABA) derivatives. Iodination of the intermediary zirconium species gave the α-iodomethylated γ-aminobutyrates, which were, in turn, converted to the 5-substituted pyrrolidine-3-carboxylate having cis stereochemistry.
本文报道了N-烯基氨基甲酸酯衍生物的锆介导的不对映选择性烯烃-羰基偶联反应。目前,使用在均烯丙基位置具有取代基的手性叔丁基-3-丁烯基氨基甲酸酯的烯烃-羰基偶联反应以高度的不对映选择性进行,得到β-甲基-γ-取代的γ-氨基丁酸(GABA)衍生物。中间锆物种的碘化反应得到β-碘甲基化的γ-