Combining an electrophilic iron complex [Fe(Fpda)(THF)]2 (3) [Fpda=N,N’-bis(pentafluorophenyl)-o-phenylenediamide] with the pre-activation of a-alkyl-substituted a-diazoesters reagents by LiAl(ORF)4 [ORF=(OC(CF3)3] provides unprecedented access to selective iron-catalyzed intramolecular functionalization of strong alkyl C(sp3)-H bonds. Reactions occur at 25°C via a-alkyl-metallocarbene intermediates, and with activity/selectivity levels similar to those of rhodium carboxylate catalysts. Mechanistic investigations reveal a crucial role of the