Volume 64, Issue 30 e202507804
Research Article

Organocatalytic Asymmetric Cycloaddition for the Construction of Chiral Indole-Fused Medium- and Large-Sized Rings

Bo-Wen Lai

Bo-Wen Lai

Research Center of Chiral Functional Heterocycles, School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou, 221116 P.R. China

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Hao-Hui Zhang

Hao-Hui Zhang

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

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Bo-Xuan Yao

Bo-Xuan Yao

Department of Chemistry, Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province, Shantou University, and Chemistry and Chemical Engineering Guangdong Laboratory, Shantou, 515063 P.R. China

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Rui Li

Rui Li

Research Center of Chiral Functional Heterocycles, School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou, 221116 P.R. China

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Dr. Shao-Fei Ni

Corresponding Author

Dr. Shao-Fei Ni

Department of Chemistry, Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province, Shantou University, and Chemistry and Chemical Engineering Guangdong Laboratory, Shantou, 515063 P.R. China

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

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Prof. Dr. Kuiyong Dong

Corresponding Author

Prof. Dr. Kuiyong Dong

Research Center of Chiral Functional Heterocycles, School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou, 221116 P.R. China

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

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Prof. Dr. Feng Shi

Corresponding Author

Prof. Dr. Feng Shi

Research Center of Chiral Functional Heterocycles, School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou, 221116 P.R. China

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

Institute of Functional Heterocycles, School of Petrochemical Engineering, Changzhou University, Changzhou, 213164 P.R. China

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

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First published: 20 May 2025

Graphical Abstract

The first catalytic asymmetric (4 + 4) and (4 + 4 + m) cycloadditions of 2-indolylacetates have been established via asymmetric organocatalysis, providing a useful protocol for constructing enantioenriched indole-fused medium- and large-sized rings. The biological evaluation of selected chiral indole products discovered several compounds with some extent of antitumor activity, indicating their potential applications in medicinal chemistry.

Abstract

Catalytic asymmetric construction of chiral indole-fused medium- and large-sized rings represents an important issue in synthetic chemistry but with significant challenges. To overcome these challenges, herein, we report highly enantioselective synthesis of chiral indole-fused medium- and large-sized rings via organocatalytic asymmetric (4 + 4) and (4 + 4 + m) cycloadditions of 2-indolylacetates with benzofuranyl azadienes, providing an efficient strategy for accessing these enantioenriched frameworks. By designing 2-indolylacetates as a new class of four-carbon platform molecules for higher-order cycloadditions and modulating the nucleophilicity of benzofuranyl azadienes, we achieved the catalytic asymmetric synthesis of chiral indole-fused eight-membered rings and eleven- to fourteen-membered macrocycles in high yields with good enantioselectivity. This work not only demonstrates the first application of 2-indolylacetates as four-carbon platform molecules in cycloaddition reactions, but also represents the first catalytic asymmetric (4 + 4) and (4 + 4 + m) cycloadditions of 2-indolylacetates. Furthermore, biological evaluation revealed that several chiral indole derivatives exhibit some extent of antitumor activity, indicating their potential applications in medicinal chemistry.

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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