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Cross-electrophile coupling: principles of reactivity and selectivity
Daniel A Everson1, Daniel J Weix
1Department of Chemistry, University of Rochester , Rochester, New York 14627-0216, United States.
The Journal of Organic Chemistry
|May 14, 2014
Summary
Cross-electrophile coupling (XEC) joins two different electrophiles, tackling the challenge of cross-selectivity. Strategies include reagent excess, electronic/steric differentiation, and radical processes for efficient synthesis.
Area of Science:
- Organic Chemistry
- Catalysis
- Synthetic Methodology
Background:
- Cross-electrophile coupling (XEC) is a powerful synthetic tool for forming carbon-carbon bonds.
- Achieving high cross-selectivity in XEC reactions, where two different electrophiles are coupled, remains a significant challenge.
- Controlling which electrophile reacts with the catalyst and which reacts with the intermediate is crucial for synthetic efficiency.
Purpose of the Study:
- To provide a critical overview of recent advances in catalytic cross-electrophile coupling (XEC).
- To highlight strategies for controlling cross-selectivity in XEC reactions.
- To discuss the mechanistic underpinnings of successful XEC methodologies.
Main Methods:
- Review of recent synthetic advances and mechanistic studies in XEC.
- Categorization of strategies for achieving cross-selectivity.
- Illustrative examples from contemporary chemical literature.
Main Results:
- Four primary strategies for controlling cross-selectivity in XEC were identified: reagent excess, electronic differentiation, catalyst-substrate steric matching, and radical chain processes.
- Each strategy offers distinct advantages for specific substrate combinations.
- Recent literature demonstrates the successful application of these methods in complex molecule synthesis.
Conclusions:
- Overcoming the cross-selectivity challenge in XEC is achievable through rational design of reaction conditions and catalyst systems.
- The presented strategies provide a valuable framework for developing new and efficient XEC reactions.
- Continued exploration of mechanistic details will further advance the field of cross-electrophile coupling.
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