Directed Hydrogen Atom Transfer for Selective Reactions of Polyenols
Daniel E Essayan1, Matthew J Schubach1, Jeanelle M Smoot1
1Department of Chemistry, University of California, Irvine, California 92697-2025, United States.
Journal of the American Chemical Society
|June 25, 2024
Summary
Iron catalysts enable site-selective hydrogen atom transfer to alkenes, specifically targeting allylic alcohols in polyenols. This method efficiently produces valuable amino alcohols from polyenol precursors.
Area of Science:
- Organic Chemistry
- Catalysis
- Synthetic Methodology
Background:
- Hydrofunctionalization of alkenes is a fundamental transformation in organic synthesis.
- Achieving site-selectivity in radical reactions, particularly with polyfunctional substrates, remains a challenge.
- Allylic alcohols are versatile synthetic intermediates, but their selective functionalization requires tailored approaches.
Purpose of the Study:
- To develop a catalytic system for directed hydrogen atom transfer to alkenes.
- To achieve site-selective hydrofunctionalization of polyenols, focusing on the allylic alcohol motif.
- To explore the mechanism of selectivity in iron-catalyzed radical reactions.
Main Methods:
- Utilized iron complexes as catalysts for hydrogen atom transfer reactions.
- Employed polyenols as substrates for the hydrofunctionalization process.
- Investigated the role of substrate coordination to the catalyst via experimental data.
Main Results:
- Demonstrated successful site-selective hydrofunctionalization of polyenols via directed hydrogen atom transfer.
- Showcased the crucial role of hydroxy group coordination to the iron hydride intermediate in directing selectivity.
- Prepared β- and γ-amino alcohols from polyenol precursors with high selectivity.
Conclusions:
- Iron-catalyzed hydrogen atom transfer provides a novel strategy for selective alkene functionalization.
- Coordination of the hydroxyl group is key to the preferential engagement of allylic alcohols.
- This methodology offers a new basis for achieving selectivity in radical hydrofunctionalization reactions.
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