Electrophile-promoted Fe-to-N₂ hydride migration in highly reduced Fe(N₂)(H) complexes
- Creators
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Deegan, Meaghan M.
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Peters, Jonas C.
Abstract
One of the emerging challenges associated with developing robust synthetic nitrogen fixation catalysts is the competitive formation of hydride species that can play a role in catalyst deactivation or lead to undesired hydrogen evolution reactivity (HER). It is hence desirable to devise synthetic systems where metal hydrides can migrate directly to coordinated N₂ in reductive N–H bond-forming steps, thereby enabling productive incorporation into desired reduced N₂-products. Relevant examples of this type of reactivity in synthetic model systems are limited. In this manuscript we describe the migration of an iron hydride (Fe-H) to N_α of a disilylhydrazido(2-) ligand (Fe=NNR₂) derived from N₂ via double-silylation in a preceding step. This is an uncommon reactivity pattern in general; well-characterized examples of hydride/alkyl migrations to metal heteroatom bonds (e.g., (R)M=NR′ → M–N(R)R′) are very rare. Mechanistic data establish the Fe-to-N_α hydride migration to be intramolecular. The resulting disilylhydrazido(1-) intermediate can be isolated by trapping with CN^tBu, and the disilylhydrazine product can then be liberated upon treatment with an additional acid equivalent, demonstrating the net incorporation of an Fe-H equivalent into an N-fixed product.
Additional Information
© 2018 the Author(s). This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. All publication charges for this article have been paid for by the Royal Society of Chemistry. Received 31st May 2018, Accepted 26th June 2018. First published on 29th June 2018. This work was supported by the NIH (GM 070757). The authors are grateful to Larry Henling and Mike Takase for crystallographic assistance. We thank Trixia Buscagan for preliminary data on complex 4. Conflicts of interest: There are no conflicts to declare.Attached Files
Published - c8sc02380h.pdf
Supplemental Material - c8sc02380h1.pdf
Supplemental Material - c8sc02380h2.cif
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Additional details
- Alternative title
- Electrophile-promoted Fe-to-N2 hydride migration in highly reduced Fe(N2)(H) complexes
- Alternative title
- Electrophile-promoted Fe-to-N_2 hydride migration in highly reduced Fe(N_2)(H) complexes
- PMCID
- PMC6063139
- Eprint ID
- 87573
- Resolver ID
- CaltechAUTHORS:20180705-154047668
- NIH
- GM 070757
- Royal Society of Chemistry
- Created
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2018-07-06Created from EPrint's datestamp field
- Updated
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2022-03-09Created from EPrint's last_modified field