C1‐symmetric β‐Diketiminatoiron(II) Complexes for Hydroamination of Primary Alkenylamines.

The synthesis and solid‐state characterization of an array of well‐defined low‐coordinate C1‐symmetric β‐diketiminatoiron(II) alkyl complexes B3–B6 featuring steric and electronic variations on one of the N‐aryl substituents of the β‐diketiminate ligand scaffold are reported. All complexes display unique catalytic abilities of promoting the selective exo‐cyclohydroamination of unprotected 2,2‐diphenylpent‐4‐en‐1‐amine (1 a) under mild reactions conditions. The incorporation of a potentially coordinative ortho‐methoxy substituent on one of the N‐aryl rings of the β‐diketiminate skeleton, in conjunction with a more crowded 2,6‐diisopropylphenyl group on the other, affords a far more active catalyst (B3) than our previously reported C2‐symmetric β‐diketiminatoiron(II) alkyl complex B (Ar1=Ar2=2,4,6‐(Me)3C6H2)/cyclopentylamine system. Comparative studies let us postulate that this superior activity of B3, when compared with B4‐B6, is likely arising from steric effects and/or the coordinating ability of the ortho‐methoxy substituent. The scope and limitations of this novel C1‐symmetric β‐diketiminatoiron(II) alkyl complex B3 are also presented. [ABSTRACT FROM AUTHOR]