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Ate Complexes in Iron-Catalyzed Cross-Coupling Reactions
Tobias Parchomyk1, Konrad Koszinowski2
1Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr. 2, 37077, Göttingen, Germany.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|August 25, 2016
Summary
Iron-catalyzed cross-coupling reactions are key for sustainable synthesis. This study uses mass spectrometry to reveal iron ate complex structures and their crucial role in reaction mechanisms and product selectivity.
Area of Science:
- Organometallic Chemistry
- Sustainable Organic Synthesis
- Catalysis
Background:
- Iron catalysis offers a sustainable alternative for organic synthesis.
- The precise mechanisms of iron-catalyzed cross-coupling reactions are not well understood.
- Identifying key intermediates is crucial for mechanistic elucidation.
Purpose of the Study:
- To identify and characterize ionic iron species in cross-coupling reactions using electrospray-ionization mass spectrometry (ESI-MS).
- To investigate the influence of additives and ligands on the structure and reactivity of iron intermediates.
- To elucidate the mechanism of iron-catalyzed cross-coupling reactions.
Main Methods:
- Electrospray-ionization mass spectrometry (ESI-MS) for identifying ionic species.
- Study of transmetalation reactions involving iron precursors and organometallic reagents.
- Analysis of gas-phase fragmentation patterns of iron complexes.
Main Results:
- Anionic iron ate complexes with varying nuclearity and oxidation states were identified.
- The formation of a specific heteroleptic Fe(III) complex, [Ph3Fe(iPr)]-, was observed upon addition of iPrCl.
- Gas-phase fragmentation demonstrated selective reductive elimination, yielding the cross-coupling product.
Conclusions:
- ESI-MS is a powerful tool for characterizing reactive intermediates in iron catalysis.
- The structure and oxidation state of iron ate complexes are critical for catalytic activity and selectivity.
- Understanding these intermediates provides insights into optimizing iron-catalyzed cross-coupling reactions.
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