Chiral Iron Porphyrins Catalyze Enantioselective Intramolecular C(sp 3 )-H Bond Amination Upon Visible-Light Irradiation.
Hua-Hua WangHui ShaoGuanglong HuangJianqiang FanWai-Pong ToLi DangYungen LiuChi-Ming ChePublished in: Angewandte Chemie (International ed. in English) (2023)
Iron-catalyzed asymmetric amination of C(sp 3 )-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(sp 3 )-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(NSO 2 Ar) intermediate generated in situ under photochemical conditions reacts with the C(sp 3 )-H bond through a stepwise hydrogen atom transfer/radical rebound mechanism, with enantioselectivity arising from cooperative noncovalent interactions between the Fe(NSO 2 Ar) unit and the peripheral substituents of the chiral porphyrin scaffold.
Keyphrases
- visible light
- capillary electrophoresis
- iron deficiency
- ionic liquid
- photodynamic therapy
- molecular dynamics
- density functional theory
- molecular docking
- electron transfer
- metal organic framework
- energy transfer
- molecular dynamics simulations
- single cell
- gene expression
- tissue engineering
- radiation induced
- dna methylation
- solid state
- transition metal