CuII /TEMPO-Catalyzed Enantioselective C(sp3 )-H Alkynylation of Tertiary Cyclic Amines through Shono-Type Oxidation.

Pei-Sen GaoXin-Jun WengZhen-Hua WangChao ZhengBing SunZhi-Hao ChenShu-Li YouTian-Sheng Mei
Published in: Angewandte Chemie (International ed. in English) (2020)
A novel strategy for asymmetric Shono-type oxidative cross-coupling has been developed by merging copper catalysis and electrochemistry, affording C1-alkynylated tetrahydroisoquinolines with good to excellent enantioselectivity. The use of TEMPO as a co-catalytic redox mediator is crucial not only for oxidizing a tetrahydroisoquinoline to an iminium ion species but also for decreasing the oxidation potential of the reaction. A novel bisoxazoline ligand is also reported.