Rhodium(III)‐Catalyzed Enantioselective Coupling of Indoles and 7‐Azabenzonorbornadienes by C−H Activation/Desymmetrization. Issue 1 (7th December 2018)

• Record Type: Journal Article
• Authors: Yang, Xifa; Zheng, Guangfan; Li, Xingwei
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 1(2018)
• Page Start: 322
• Page End: 326
• Publication Date: 2018-12-07
• Subjects: C−H activation -- desymmetrization -- heterocycles -- rhodium -- synthetic methods; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201811998
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Chiral rhodium(III) cyclopentadienyl catalysts (Cp X Rh III ) play significant roles in asymmetric arene C−H activation. Rh/Ir‐catalyzed couplings of arenes and strained rings have been well‐studied, but they have been limited to racemic systems. Reported in this work is the Cp x Rh III /AgSbF6 ‐catalyzed enantioselective desymmetrizative C−C coupling of N ‐pyrimidylindoles and 7‐azabenzonorbornadienes with high efficiency and enantioselectivity. The role of AgSbF6 has been established by mechanistic studies. AgSbF6 enhances the catalytic activity by suppressing the C3−H activation of the indoles, activation which would otherwise lead to catalytically inactive species. Abstract : Silver screen : Cp x Rh III /AgSbF6 ‐catalyzed enantioselective desymmetrizative ring‐opening coupling of N ‐pyrimidylindoles and 7‐azabenzonorbornadienes has been realized. AgSbF6 enhances the catalytic activity by suppressing C3−H activation of the indole, which would otherwise lead to catalytically inactive species. The procedure features good functional‐group tolerance, good to excellent yields, and diastereospecificity.