Online article for Non-subscribers

Pay per view

Heterocycles has a pay-per-view service for Non-subscribers.
You will be able to directly purchase the full text article through PayPal.
Your purchased Paper can be downloaded after the payment is completed.
An e-mail will be sent the URL to download the paper.
If you have any questions, please contact: purchase@heterocycles.com

Price: ¥ 4,400 (Yen only)
Period: This Article can be accessed for 7 days.

Review | Special issue | Vol 103, No. 2, 2021, pp.592-608
Published online, 12th March, 2021
DOI: 10.3987/REV-20-SR(K)6
Combined Brønsted-Base-Mediated Direct C-H Carboxylation of Heteroarenes with CO2

Masanori Shigeno,* Keita Sasaki, Kazuya Hanasaka, Itsuki Tohara, Kanako Nozawa-Kumada, and Yoshinori Kondo*

*Graduate School of Pharmaceutical Science, Tohoku University, 6-3 Aobayama, Sendai 980-8578, Japan

Abstract

This review article summarizes that the combined Brønsted-base system comprising LiO-t-Bu, CsF, and 18-crown-6 efficiently proceeds the direct carboxylation of electron-rich heteroarenes, such as benzothiophene and benzofuran, with CO2. Good functional group compatibility is displayed, allowing the use of Me, MeO, halogen, CN, ketone, and amide moieties. 3-Substituted indoles are also used for C-2 carboxylation, while double-carboxylation of 2-alkylheteroarenes is achieved by LiO-t-Bu and CsF.