Details

Autor(en) / Beteiligte

• Song, Lei
• Fu, Dong‐Min
• Chen, Liang
• Jiang, Yuan‐Xu
• Ye, Jian‐Heng
• Zhu, Lei
• Lan, Yu
• Fu, Qiang
• Yu, Da‐Gang

Titel

Visible‐Light Photoredox‐Catalyzed Remote Difunctionalizing Carboxylation of Unactivated Alkenes with CO2

Ist Teil von

• Angewandte Chemie International Edition, 2020-11, Vol.59 (47), p.21121-21128

Auflage

International ed. in English

Ort / Verlag

Weinheim: Wiley Subscription Services, Inc

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Remote difunctionalization of unactivated alkenes is challenging but a highly attractive tactic to install two functional groups across long distances. Reported herein is the first remote difunctionalization of alkenes with CO2. This visible‐light photoredox catalysis strategy provides a facile method to synthesize a series of carboxylic acids bearing valuable fluorine‐ or phosphorus‐containing functional groups. Moreover, this versatile protocol shows mild reaction conditions, broad substrate scope, and good functional‐group tolerance. Based on DFT calculations, a radical adds to an unactivated alkene to smoothly form a new carbon radical, followed by a 1,5‐hydrogen atom‐transfer process, the rate‐limiting step, generating a more stable benzylic radical. The reduction of the benzylic radicals by an IrII species generates the corresponding benzylic carbanions as the key intermediates, which further undergo nucleophilic attack with CO2 to generate carboxylates. Reported is the first remote difunctionalization of unactivated alkenes with CO2 by visible‐light photoredox catalysis. Mechanistic studies indicate that a 1,5‐hydrogen atom‐transfer process is the rate‐limiting step and reduction of radical intermediates generates the corresponding carbanions. Other electrophiles, including aldehydes, ketones, and benzylic bromides, are also applicable in this process, demonstrating a general strategy for redox‐neutral remote difunctionalization of unactivated alkenes.