Palladium-Catalyzed Asymmetric (4 + 2) Annulation of γ-Methylidene-δ-valerolactones with Alkenes: Enantioselective Synthesis of Functionalized Chiral Cyclohexyl Spirooxindoles
作者:Zhi-Long Jia、Xian-Tao An、Yu-Hua Deng、Lin-Han Pang、Chun-Fang Liu、Le-Le Meng、Jia-Kun Xue、Xian-He Zhao、Chun-An Fan
DOI:10.1021/acs.orglett.0c03963
日期:2021.2.5
(S,S,S)-(−)-Xyl-SKP, offering a new approach for the diastereo- and enantioselective synthesis of chiral cyclohexadienone-fused cyclohexyl spirooxindoles. Significantly, three highly congested contiguous tetrasubstituted carbon atoms embedded in bispirocyclic skeleton, of which two are vicinal quaternary stereogenic centers, are forged in an effective and selective manner (up to 99% yield, up to 95%
前所未有的不对称催化(4 + 2)环芳基取代的γ亚甲基δ戊内酯(GMDVs)与靛红衍生的反应段-quinone甲基化物(p -QMs)已被钯(0)的催化下开发和(S,S,S)-(-)-Xyl-SKP,为手性环己二烯酮稠合的环己基spirooxindoles的非对映和对映选择性合成提供了新方法。显着地,以有效和选择性的方式锻造了嵌入双螺环骨架中的三个高度拥挤的连续四取代碳原子,其中两个是邻近的季位立体中心(最高产率为99%,ee高达95%,> 20/1 dr) 。当前的反应代表了在GMDV和p -QM的化学反应中形成六元碳环的对映选择性催化(4 + 2)环空的首次探索。