Visible-Light-Mediated Enantioselective Photoreactions of 3-Alkylquinolones with 4-O-Tethered Alkenes and Allenes
Visible-Light-Mediated Enantioselective Photoreactions of 3-Alkylquinolones with 4-O-Tethered Alkenes and Allenes
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DOI：
10.1021/acs.orglett.0c01065
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发表时间：
2020-05-01
期刊：
影响因子：
5.2
通讯作者：
Bach, Thorsten
中科院分区：
文献类型：
--
作者：
Li, Xinyao;Jandl, Christian;Bach, Thorsten
标题化合物在手性增敏剂存在的情况下，在可见光照射下发生分子内[2+2]光环加成反应。在催化剂负载量低至0.5mol%的情况下，在一步中形成多达四个确定的立体中心(14个具有系链的烯烃，6个具有烯，72-99%的产率，81-99%的ee)。3-位上的烷基对反应的成功至关重要，因为它会导致三重态能量的显著降低。
The title compounds undergo intramolecular [2 + 2] photocycloaddition reactions when irradiated with visible light in the presence of a chiral sensitizer. Up to four defined stereogenic centers are formed in a single step (14 examples with a tethered alkene, 6 examples with an allene, 72-99% yield, 81-99% ee) at catalyst loadings as low as 0.5 mol %. The alkyl group in the 3-position is crucial for the success of the reaction as it leads to a significant decrease of the triplet energy.