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Imine Metathesis by Silica-Supported Catalysts Using the Methodology of Surface Organometallic Chemistry
Published on: October 18, 2019
Practical new silyloxy-based alkyne metathesis catalysts with optimized activity and selectivity profiles
Johannes Heppekausen1, Robert Stade, Richard Goddard
1Max-Planck-Institut für Kohlenforschung, D-45470 Mülheim/Ruhr, Germany.
Journal of the American Chemical Society
|August 12, 2010
Summary
New molybdenum alkylidyne complexes with triphenylsilanolate ligands enable versatile alkyne metathesis reactions. These catalysts offer high functional group tolerance and can be easily handled, even at ambient temperature.
Area of Science:
- Organometallic Chemistry
- Catalysis
- Organic Synthesis
Background:
- Alkyne metathesis is a crucial reaction in organic synthesis for forming carbon-carbon bonds.
- Development of highly reactive, functional group tolerant, and easily handled catalysts remains a key challenge.
Purpose of the Study:
- To develop novel molybdenum alkylidyne complexes for alkyne metathesis.
- To investigate the catalytic activity, stability, and scope of these new complexes.
- To optimize reaction conditions for improved efficiency and broader applicability.
Main Methods:
- Synthesis of molybdenum alkylidyne complexes featuring triphenylsilanolate ligands.
- In situ generation of active species from molybdenum nitride precursors.
- Complexation with 1,10-phenanthroline to form air-stable adducts.
- Catalytic testing in various inter- and intramolecular alkyne metathesis reactions.
- Optimization using molecular sieves and X-ray crystallography for structural analysis.
Main Results:
- Triphenylsilanolate ligands impart excellent reactivity and functional group tolerance to molybdenum alkylidyne catalysts.
- Air-stable phenanthroline adducts can be readily activated for catalysis.
- Reactions proceed efficiently at ambient temperature, with significant yield and rate improvements observed using molecular sieves.
- Successful application in the synthesis of bioactive natural products demonstrates broad scope.
Conclusions:
- Novel molybdenum alkylidyne complexes with triphenylsilanolate ligands represent a new generation of highly effective alkyne metathesis catalysts.
- These catalysts offer a practical choice for practitioners due to their ease of handling, broad applicability, and tolerance.
- The use of molecular sieves enhances reaction efficiency, enabling milder reaction conditions and simplifying substrate requirements.
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