C-Halide bond cleavage by a two-coordinate iron(i) complex

Area of Science:

• Organometallic Chemistry
• Catalysis
• Synthetic Organic Chemistry

Background:

• Iron(I) species are implicated as crucial intermediates in Kumada-type C-C cross-coupling catalysis.
• The reactivity of well-defined, isolable iron(I) complexes with organohalides remains largely unexplored.

Purpose of the Study:

• To investigate the reactivity of a specific two-coordinate iron(I) complex, K{18c6}[Fe(N(SiMe3)2)2], towards various organohalides.
• To elucidate the mechanism of carbon-halide bond cleavage mediated by this iron(I) complex.

Main Methods:

• Synthesis and characterization of the two-coordinate iron(I) complex.
• Reactions with diverse organohalides (including aryl and alkyl halides, and fluoroarenes).
• Mechanistic studies involving spectroscopic and computational analyses.

Main Results:

• The iron(I) complex demonstrated rapid cleavage of various carbon-halide bonds, notably including robust C-F bonds.
• Mechanistic investigations supported a stepwise one-electron transfer pathway.
• The formation of intermediate organoradicals was indicated.

Conclusions:

• The studied iron(I) complex is highly effective in activating C-X bonds, expanding the scope of iron-catalyzed cross-coupling.
• The findings provide valuable insights into the role of iron(I) in organohalide activation and radical generation.
• This work paves the way for developing novel iron-based catalytic systems for challenging coupling reactions.