Well-Defined Four-Coordinate Iron(II) Complexes For Intramolecular Hydroamination of Primary Aliphatic Alkenylamines.

Despite the growing interest in iron catalysis and hydroamination reactions, iron-catalyzed hydroamination of unprotected primary aliphatic amines and unactivated alkenes has not been reported to date. Herein, a novel well-defined four-coordinate β-diketiminatoiron(II) alkyl complex is shown to be an excellent precatalyst for the highly selective cyclohydroamination of primary aliphatic alkenylamines at mild temperatures (70-90 °C). Both empirical kinetic analyses and the reactivity of an isolated iron(II) amidoalkene dimer, [LFe(NHCH₂CPh₂CH₂CHCH₂)]₂ favor a stepwise σ-insertive mechanism that entails migratory insertion of the pendant alkene into an iron-amido bond associated with a rate-determining aminolysis step. [ABSTRACT FROM AUTHOR]