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Gold carbenoids: lessons learnt from a transmetalation approach
Günter Seidel1, Barbara Gabor, Richard Goddard
1Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr (Germany).
Angewandte Chemie (International Ed. in English)
|November 29, 2013
Summary
Researchers explored gold carbenoid formation using transmetalation. Stabilized gold carbenoids formed easily, but unstabilized ones proved difficult, impacting understanding of π-acid catalysis.
Area of Science:
- Organometallic Chemistry
- Catalysis
Background:
- Gold(I) catalysts facilitate nucleophilic addition to π systems.
- The mechanism often involves proposed gold carbenoid intermediates, but direct observation remains challenging.
- Current understanding relies heavily on indirect evidence and debated computational data.
Purpose of the Study:
- To investigate a synthetic route to gold carbenoids via transmetalation.
- To characterize intermediates formed during the reaction of Fischer carbene complexes with [LAu](+).
Main Methods:
- Formal transmetalation of chromium or tungsten Fischer carbene complexes with electrophilic gold(I) species ([LAu](+)).
- Characterization of reaction intermediates, including unusual bimetallic arrays.
Main Results:
- The transmetalation proceeded readily when the carbene center possessed a stabilizing heteroelement.
- In the absence of a stabilizing heteroelement, the reaction stalled, forming bimetallic complexes.
- These findings highlight the difficulty in generating "unstabilized" gold carbenoids.
Conclusions:
- The study provides insights into the formation and stability of gold carbenoids.
- The challenges in generating unstabilized gold carbenoids have implications for the broader understanding of π-acid catalysis mechanisms.
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