Li Ke, Li Changkun
Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
Org Lett. 2020 Dec 18;22(24):9456-9461. doi: 10.1021/acs.orglett.0c03383. Epub 2020 Dec 2.
The first highly regio- and enantioselective synthesis of 3-allylindolizines has been developed by the sequential Rh-catalyzed asymmetric allylation and Tschitschibabin reaction. Above the 20:1 branch/linear ratio, up to a 96% yield and 99% could be obtained with the help of -butyl-substituted chiral bisoxazolinephosphine ligand. In situ generated highly nucleophilic 2-alkylpyridinium ylides are utilized to undergo the asymmetric alkylation reaction before cyclization.
通过连续的铑催化不对称烯丙基化反应和契奇巴宾反应,首次实现了3-烯丙基中氮茚的高度区域和对映选择性合成。在20:1的支链/线性比例以上,借助叔丁基取代的手性双恶唑啉膦配体,可获得高达96%的产率和99%的对映体过量值。原位生成的高亲核性2-烷基吡啶叶立德在环化之前用于进行不对称烷基化反应。