Details

Autor(en) / Beteiligte

• Wang, Hua‐Hua
• Shao, Hui
• Huang, Guanglong
• Fan, Jianqiang
• To, Wai‐Pong
• Dang, Li
• Liu, Yungen
• Che, Chi‐Ming

Titel

Chiral Iron Porphyrins Catalyze Enantioselective Intramolecular C(sp3)−H Bond Amination Upon Visible‐Light Irradiation

Ist Teil von

• Angewandte Chemie International Edition, 2023-05, Vol.62 (19), p.e202218577-n/a

Auflage

International ed. in English

Ort / Verlag

Germany: Wiley Subscription Services, Inc

Erscheinungsjahr

2023

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Iron‐catalyzed asymmetric amination of C(sp3)−H bonds is appealing for synthetic applications due to the biocompatibility and high earth abundance of iron, but examples of such reactions are sparse. Herein we describe chiral iron complexes of meso‐ and β‐substituted‐porphyrins that can catalyze asymmetric intramolecular C(sp3)−H amination of aryl and arylsulfonyl azides to afford chiral indolines (29 examples) and benzofused cyclic sulfonamides (17 examples), respectively, with up to 93 % ee (yield: up to 99 %) using 410 nm light under mild conditions. Mechanistic studies, including DFT calculations, for the reactions of arylsulfonyl azides reveal that the Fe(NSO2Ar) intermediate generated in situ under photochemical conditions reacts with the C(sp3)−H bond through a stepwise hydrogen atom transfer/radical rebound mechanism, with enantioselectivity arising from cooperative noncovalent interactions between the Fe(NSO2Ar) unit and the peripheral substituents of the chiral porphyrin scaffold. An efficient method has been developed for the chiral iron porphyrin catalyzed transformation of aryl and arylsulfonyl azides into chiral indolines and sultams, respectively. The reaction proceeds upon visible light irradiation and with high yields and excellent enantioselectivities.