Catalytic Asymmetric Dearomatization of Indolyl Dihydropyridines through an Enamine
Zi-Lei Xia1, Chao Zheng1, Shou-Guo Wang1
1State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai, 200032, China.
Abstract:
A highly efficient synthesis of enantioenriched spiroindolines by catalytic asymmetric dearomatization of indolyl dihydropyridines through a chiral phosphoric acid catalyzed enamine isomerization/spirocyclization/transfer hydrogenation sequence has been developed. This reaction proceeds under mild reaction conditions, affording novel spiroindolines in good yields (up to 88 %) with excellent enantioselectivity (up to 97 % ee). DFT calculations provide insights into the reaction mechanism as well as the origin of stereochemistry.
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