Volume 136, Issue 6 e202318268
Forschungsartikel

Friedel–Crafts Acylation for Accessing Multi-Bridge-Functionalized Large Pillar[n]arenes

Dr. Tan-Hao Shi

Dr. Tan-Hao Shi

Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, 615-8510 Kyoto, Japan

Search for more papers by this author
Prof. Dr. Shigehisa Akine

Prof. Dr. Shigehisa Akine

WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, 920-1192 Kanazawa, Ishikawa, Japan

Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, 920-1192 Kanazawa, Ishikawa, Japan

Search for more papers by this author
Dr. Shunsuke Ohtani

Dr. Shunsuke Ohtani

Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, 615-8510 Kyoto, Japan

Search for more papers by this author
Dr. Kenichi Kato

Dr. Kenichi Kato

Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, 615-8510 Kyoto, Japan

Search for more papers by this author
Prof. Dr. Tomoki Ogoshi

Corresponding Author

Prof. Dr. Tomoki Ogoshi

Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, 615-8510 Kyoto, Japan

WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, 920-1192 Kanazawa, Ishikawa, Japan

Search for more papers by this author
First published: 18 December 2023
Citations: 1

Abstract

Pillar[n]arenes can be constructed using a Friedel–Crafts alkylation process. However, due to the reversible nature of the alkylation, mixture of large pillar[n]arenes (n≥7) are obtained as minor products, and thus laborious purification are necessary to isolate the larger pillar[n]arenes. Moreover, inert methylene bridges are introduced during the alkylation process, and the multi-functionalization of the bridges has never been investigated. Herein, an irreversible Friedel–Crafts acylation is used to prepare pillar[n]arenes. Due to the irreversible nature of the acylation, the reaction of precursors bearing carboxylic acids and electron-rich arene rings results in a size-exclusive formation of pillar[n]arenes, in which the ring-size is determined by the precursor length. Because of this size-selective formation, laborious separation of undesired macrocycles is not necessary. Moreover, the bridges of pillar[n]arenes are selectively installed with reactive carbonyl groups using the acylation method, whose positions are determined by the precursor used. The carbonyl bridges can be easily converted into versatile functional groups, leading to various laterally modified pillar[n]arenes, which cannot be accessed by the alkylation strategy.

Conflict of interest

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

The full text of this article hosted at iucr.org is unavailable due to technical difficulties.