Chiral Iron Porphyrins Catalyze Enantioselective Intramolecular C(sp3 )-H Bond Amination Upon Visible-Light Irradiation.
Angew Chem Int Ed Engl
; 62(19): e202218577, 2023 May 02.
Article
en En
| MEDLINE
| ID: mdl-36716145
ABSTRACT
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 ß-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 410â
nm light under mild conditions. Mechanistic studies, including DFT calculations, for the reactions of arylsulfonyl azides reveal that the Fe(NSO2 Ar) 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(NSO2 Ar) unit and the peripheral substituents of the chiral porphyrin scaffold.
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MEDLINE
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Año:
2023
Tipo del documento:
Article
País de afiliación:
China