Wang Xin-Wei, Huang Wen-Jun, Wang Han, Wu Bo, Zhou Yong-Gui
State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023, P. R. China.
Zhang Dayu School of Chemistry, Dalian University of Technology, Dalian 116024, P. R. China.
Org Lett. 2022 Mar 4;24(8):1727-1731. doi: 10.1021/acs.orglett.2c00368. Epub 2022 Feb 24.
Compared with the well-established asymmetric Pictet-Spengler reactions on the pyrrole ring of indoles, the catalytic asymmetric Pictet-Spengler reaction on the benzene ring of indoles has been rarely studied. Herein the C6-selective Pictet-Spengler reactions of indoles have been realized by employing 2-(1-indol-7-yl)anilines and isatins in the presence of chiral phosphoric acid, affording novel polycyclic indole derivatives bearing spiro quaternary stereocenters in excellent yields with excellent enantioselectivities. This reaction could be conducted on the gram scale without any loss of activity or enantioselectivity.
与在吲哚吡咯环上已成熟的不对称Pictet-Spengler反应相比，在吲哚苯环上的催化不对称Pictet-Spengler反应很少被研究。在此，通过在手性磷酸存在下使用2-(1-吲哚-7-基)苯胺和异吲哚酮，实现了吲哚的C6选择性Pictet-Spengler反应，以优异的产率和对映选择性得到了带有螺环季碳立体中心的新型多环吲哚衍生物。该反应可以在克级规模上进行，而不会损失任何活性或对映选择性。
