Selective Iron Catalyzed Synthesis of N-alkylated Indolines and Indoles
Résumé
Whereas iron catalysts usually promote catalyzed C3-alkylation of indole derivatives via borrowing-hydrogen methodology using alcohols as the electrophilic partners, this contribution shows how to switch the selectivity towards N-alkylation. Thus starting from indoline derivatives, N-alkylation was efficiently performed using a tricarbonyl(cyclopentadienone) iron complex as the catalyst in trifluoroethanol in the presence of alcohols leading to the corresponding N-alkylated indoline derivatives in 31-99% yields (28 examples). It is then shown a one-pot, two-step strategy, for the selective N-alkylation of indolines then their oxidations, leading to the corresponding N-alkylated indoles in 31-90% yields (15 examples). This unprecedented oxidation methodology involves an iron salt catalyst associated to TEMPO and a stoichiometric amount of t- BuOOH at RT.
Domaines
Chimie
Fichier principal
Wu - Selective Iron Catalyzed Synthesis of N‐Alkylated Indolines and Indoles.pdf (5.06 Mo)
Télécharger le fichier
Origine : Publication financée par une institution