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The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
Synthesis of 1,1-disubstituted alkenes via a Ru-catalyzed addition
B M Trost1, A B Pinkerton, F D Toste
1Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA.
Journal of the American Chemical Society
|December 14, 2001
Summary
Ruthenium complexes catalyze the addition of alkynes to alkenes, offering an atom-economical route to 1,1-disubstituted alkenes. This novel method achieves high regioselectivity and chemoselectivity under mild conditions.
Area of Science:
- Organic Chemistry
- Catalysis
- Synthetic Methodology
Background:
- Traditional olefination protocols for synthesizing 1,1-disubstituted alkenes often suffer from poor atom economy.
- Developing atom-economical strategies is crucial for sustainable chemical synthesis.
Purpose of the Study:
- To explore ruthenium-catalyzed addition of terminal alkynes to alkenes as an atom-economical synthetic strategy.
- To discover new ruthenium complexes that can efficiently catalyze this transformation.
Main Methods:
- Screening of ruthenium complexes for alkyne-alkene addition.
- Optimization of reaction conditions, including temperature, solvent, and catalyst loading.
- Characterization of reaction products and mechanistic studies.
Main Results:
- Two novel ruthenium complexes, cyclopentadienylruthenium (triphenylphosphine) camphorsulfonate and cyclopentadienylruthenium tris(acetonitrile) hexafluorophosphate, were identified.
- The reactions proceed efficiently at ambient temperature in acetone or DMF, respectively.
- High regioselectivity (9:1 to >25:1) for 1,1-disubstituted alkenes and excellent chemoselectivity were observed, tolerating various functional groups.
Conclusions:
- The developed ruthenium-catalyzed reaction provides an atom-economical and highly selective method for synthesizing 1,1-disubstituted alkenes.
- The mechanism likely involves a reversible metallacyclopentene intermediate, with chemo- and regioselectivity governed by kinetic and thermodynamic factors.
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