Photocatalytic Carboxylation of C−N Bonds in Cyclic Amines with CO2 by Consecutive Visible‐Light‐Induced Electron Transfer

• Published in: Angewandte Chemie International Edition Vol. 62; no. 11; pp. e202217918 - n/a
• Main Authors: Chen, Lin, Qu, Quan, Ran, Chuan‐Kun, Wang, Wei, Zhang, Wei, He, Yi, Liao, Li‐Li, Ye, Jian‐Heng, Yu, Da‐Gang
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 06-03-2023
• Edition: International ed. in English
• Subjects: Amines; Amino acids; Carbon Dioxide; Carboxylation; Cyclic Amines; Electron Transfer; Intermediates; Photocatalysis; Photoredox Catalysis; Selectivity; Substrates
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202217918

Visible‐light photocatalytic carboxylation with CO2 is highly important. However, it still remains challenging for reluctant substrates with low reduction potentials. Herein, we report a novel photocatalytic carboxylation of C−N bonds in cyclic amines with CO2 via consecutive photo‐induced electron transfer (ConPET). It is also the first photocatalytic reductive ring‐opening reaction of azetidines, pyrrolidines and piperidines. This strategy is practical to transform a variety of easily available cyclic amines to valuable β‐, γ‐, δ‐ and ϵ‐amino acids in moderate‐to‐excellent yields. Moreover, the method also features mild and transition‐metal‐free conditions, high selectivity, good functional‐group tolerance, facile scalability and product derivations. Mechanistic studies indicate that the ConPET might be the key to generating highly reactive photocatalysts, which enable the reductive activation of cyclic amines to generate carbon radicals and carbanions as the key intermediates.
A photocatalytic carboxylation of C−N bonds in cyclic amines with CO2 is realized by consecutive photo‐induced electron transfer (ConPET). This mild and transition‐metal‐free protocol provides a general and practical route to valuable β‐, γ‐, δ‐ and ϵ‐amino acids.