Volume 64, Issue 24 e202506465
Research Article

Modification of [2.2]Paracyclophanes via Cobalt/Salox-Catalyzed Enantioselective Electrooxidative or Photoredox C─H Acyloxylation and Alkoxylation

Fan-Rui Huang

Fan-Rui Huang

Department of Chemistry, Zhejiang University, Hangzhou, 310027 China

Both authors contributed equally to this work.

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Ming-Ya Teng

Ming-Ya Teng

Department of Chemistry, Zhejiang University, Hangzhou, 310027 China

Both authors contributed equally to this work.

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Hui Qiu

Hui Qiu

Department of Chemistry, Zhejiang University, Hangzhou, 310027 China

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Qi-Jun Yao

Corresponding Author

Qi-Jun Yao

Department of Chemistry, Zhejiang University, Hangzhou, 310027 China

E-mail: [email protected]; [email protected]

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Bing-Feng Shi

Corresponding Author

Bing-Feng Shi

Department of Chemistry, Zhejiang University, Hangzhou, 310027 China

School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, 453007 China

College of Material Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou, 311121 China

E-mail: [email protected]; [email protected]

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First published: 07 April 2025
Citations: 3

Graphical Abstract

An efficient protocol with an excellent s-factor for the preparation of chiral [2.2]paracyclophanes through cobalt-catalyzed enantioselective C─H oxygenation was developed. This approach leverages traceless electrons or oxygen to replace traditional stoichiometric metal oxidants, facilitating the reaction under mild conditions with broad scope.

Abstract

Chiral [2.2]paracyclophanes (PCPs) have widespread application in asymmetric catalysis and materials science. However, enantioselective C─H activation of PCPs remains elusive and challenging due to steric hindrance, which differs significantly from conventional aryl C─H bonds. Herein, we present a cobalt/Salox-catalyzed enantioselective dehydrogenative C─H acyloxylation and alkoxylation of racemic PCPs with carboxylic acids and alcohols under electrooxidative or photoredox conditions. This innovative approach leverages traceless electrons or oxygen to replace traditional stoichiometric metal oxidants, allowing the reaction to proceed under mild conditions. The method enables the efficient synthesis of oxygenated optically enriched PCPs, achieving yields of up to 50% with 99% ee, as well as up to 49% yields and 99% ee for the recovered starting materials, resulting in exceptional s-factors of up to 1057. The reaction exhibits a broad scope, accommodating a diverse array of carboxylic acids, including complicated natural products and pharmaceutical molecules. This strategy not only provides an efficient route for synthesizing optically enriched PCP compounds but also highlights the potential of electrooxidative and photoredox methodologies in asymmetric C─H activation reactions.

Conflict of Interests

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available in the Supporting Information of this article.

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