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Iron catalysed Negishi cross-coupling using simple ethyl-monophosphines
Caleb A Brown1, Terence A Nile, Mary F Mahon
1Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK. r.l.webster@bath.ac.uk.
Dalton Transactions (Cambridge, England : 2003)
|March 3, 2015
Summary
Iron-catalyzed Negishi cross-coupling reactions utilize monophosphines as pro-ligands. The simplest phosphine offers optimal conditions for high yields and cost-effectiveness in diarylmethane synthesis.
Area of Science:
- Organometallic Chemistry
- Catalysis
- Synthetic Organic Chemistry
Background:
- Monophosphines are crucial in catalysis, particularly in iron-catalyzed reactions.
- Negishi cross-coupling is a vital method for forming carbon-carbon bonds.
Purpose of the Study:
- To investigate monophosphines as pro-ligands in iron-catalyzed Negishi cross-coupling.
- To optimize reaction conditions for diarylmethane synthesis.
- To evaluate the electronic properties of monophosphines on catalytic activity.
Main Methods:
- Preparation of monophosphines via iron-catalyzed hydrophosphination.
- Iron-catalyzed Negishi cross-coupling of alkyl bromides with diphenyl zinc reagents.
- In situ catalyst generation and isolation of a discrete iron-phosphine complex.
Main Results:
- The simplest, unsubstituted monophosphine provided optimal reaction conditions.
- High yields of diarylmethane products were achieved.
- Cost-effectiveness was considered in ligand selection.
Conclusions:
- Monophosphines are effective pro-ligands for iron-catalyzed Negishi cross-coupling.
- Ligand structure significantly impacts catalytic efficiency and cost.
- A discrete iron-phosphine complex can be isolated and utilized in catalysis.
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