general, and functional group tolerant intramolecular hydroalkoxylation and hydroacyloxylation of unactivated olefins using a Co(salen) complex, an N-fluoropyridinium salt, and a disiloxane reagent is described. This reaction was carried out at room temperature and afforded five- and six-membered oxygen heterocyclic compounds, such as cyclic ethers and lactones. The Co complex was optimized for previously
描述了使用 Co(salen) 配合物、N-氟吡啶鎓盐和二硅氧烷试剂对未活化烯烃进行温和、通用和官能团耐受的分子内加氢烷氧基化和加氢酰氧基化。该反应在室温下进行,得到五元和六元氧杂环化合物,如环醚和内酯。通过未活化烯烃的加氢官能化,Co 配合物针对先前稀有介质环的形成进行了优化。强大的 Co 催化剂体系还可以使 O-保护的链烯醇脱保护加氢烷氧基化和链烯基酯加氢酰氧基化,直接得到环醚和内酯。研究了脱保护的底物范围和机理证明。
Stereoselective Construction of Substituted Chromans by Palladium-Catalyzed Cyclization of Propargylic Carbonates with 2-(2-Hydroxyphenyl)acetates
作者:Masahiro Yoshida、Mariko Higuchi、Kozo Shishido
DOI:10.1021/ol901964z
日期:2009.10.15
Highly substituted chromans have been constructed in a highly stereoselective manner by a palladium-catalyzed reaction of propargylic carbonates with 2-(2-hydroxyphenyl)acetates. Enantioselective reactions also successfully proceeded to give the optically active chromans with high enantioselectivity.