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Photogeneration of N-Heterocyclic Carbenes: Application in Photoinduced Ring-Opening Metathesis Polymerization
Published on: November 29, 2018
Expanded ring and functionalised expanded ring N-heterocyclic carbenes as ligands in catalysis
Abeer Binobaid1, Manuel Iglesias, Dirk J Beetstra
1School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, UKCF10 3AT.
Dalton Transactions (Cambridge, England : 2003)
|May 8, 2010
Summary
New N-heterocyclic carbene (NHC) ligands and their rhodium/iridium complexes show enhanced activity and stability for hydrogenation reactions. These catalysts operate effectively under mild conditions, offering a greener approach to chemical synthesis.
Area of Science:
- Organometallic Chemistry
- Catalysis
- Synthetic Chemistry
Background:
- N-heterocyclic carbenes (NHCs) are versatile ligands in organometallic chemistry.
- Functionalized NHC ligands can tune the properties of metal complexes for catalysis.
- Rhodium and iridium complexes are widely used catalysts for hydrogenation.
Purpose of the Study:
- To synthesize novel 6- and 7-membered NHC precursors with anisidyl or pyridine N-substituents.
- To prepare and characterize the corresponding rhodium(I) and iridium(I) complexes.
- To evaluate the catalytic activity of these complexes in hydrogenation reactions.
Main Methods:
- Synthesis of functionalized NHC precursors.
- Preparation and characterization of metal complexes (M(COD)(NHC)Cl) using techniques like X-ray crystallography.
- Catalytic hydrogenation of various substrates using molecular hydrogen.
Main Results:
- Successful synthesis and characterization of novel NHC precursors and their rhodium/iridium complexes.
- Obtained an unusual Rh(III)/Rh(I) salt with pyridyl-functionalized NHC ligands.
- Demonstrated enhanced activity and stability of the synthesized complexes in hydrogenation of 1-cyclooctadiene and 2-methyl styrene under mild conditions.
Conclusions:
- The developed functionalized NHC ligands and their metal complexes represent advanced catalysts for hydrogenation.
- These catalysts exhibit superior performance compared to non-functionalized analogues.
- The ability to operate under ambient temperature and pressure highlights their potential for sustainable chemistry.
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