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Enantioselective Intermolecular C-H Amination Directed by a Chiral Cation.

Accepted version
Peer-reviewed

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Article

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Authors

Fanourakis, Alexander 
Williams, Benjamin D 
Paterson, Kieran J 

Abstract

The enantioselective amination of C(sp3)-H bonds is a powerful synthetic transformation yet highly challenging to achieve in an intermolecular sense. We have developed a family of anionic variants of the best-in-class catalyst for Rh-catalyzed C-H amination, Rh2(esp)2, with which we have associated chiral cations derived from quaternized cinchona alkaloids. These ion-paired catalysts enable high levels of enantioselectivity to be achieved in the benzylic C-H amination of substrates bearing pendant hydroxyl groups. Additionally, the quinoline of the chiral cation appears to engage in axial ligation to the rhodium complex, providing improved yields of product versus Rh2(esp)2 and highlighting the dual role that the cation is playing. These results underline the potential of using chiral cations to control enantioselectivity in challenging transition-metal-catalyzed transformations.

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Keywords

3402 Inorganic Chemistry, 3405 Organic Chemistry, 34 Chemical Sciences

Journal Title

J Am Chem Soc

Conference Name

Journal ISSN

0002-7863
1520-5126

Volume Title

143

Publisher

American Chemical Society (ACS)

Rights

All rights reserved
Sponsorship
Engineering and Physical Sciences Research Council (EP/N005422/1)
European Research Council (757381)
Royal Society (URF\R\191003)
EPSRC, European Research Council, Royal Society, Cambridge Trust