Volume 137, Issue 9 e202421599
Forschungsartikel

CO2 Reduction at a Borane-Modified Iron Complex: A Secondary Coordination Sphere Strategy

Connor S. Durfy

Connor S. Durfy

Department of Chemistry, Western University, 1151 Richmond Street, London, ON, N8K 3G6 Canada

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Joseph A. Zurakowski

Joseph A. Zurakowski

Department of Chemistry, Western University, 1151 Richmond Street, London, ON, N8K 3G6 Canada

Department of Chemistry and Biochemistry, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4 Canada

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Dr. Marcus W. Drover

Corresponding Author

Dr. Marcus W. Drover

Department of Chemistry, Western University, 1151 Richmond Street, London, ON, N8K 3G6 Canada

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First published: 07 January 2025

Abstract

This work addresses fundamental questions that deepen our understanding of secondary coordination sphere effects on carbon dioxide (CO2) reduction using derivatized hydride analogues of the type, [Cp*Fe(diphosphine)H] (Cp* = C5Me5) – a well-studied family of organometallic complex – as models. More precisely, we describe the general reactivity of [(Cp*-BR2)Fe(diphosphine)H], which contains an intramolecularly positioned Lewis acid, and its cooperative reactivity with CO2. Control experiments underscore the critical nature of borane incorporation for transforming CO2 to reduced products, a reaction that does not occur for unfunctionalized [Cp*Fe(diphosphine)H]. Additional experiments highlight relevance of borane hybridization and substituent effects. Mechanistic studies performed in the presence and absence of CO2 emphasize the significance of carbonyl substrate to catalyst longevity. Lessons from these reactions were also transferable – with such borane-containing complexes enabling the chemoselective reduction of aldehydes in the presence of alkenes. These findings provide valuable insights into metal-ligand cooperative design strategies for carbonyl reduction and illustrate the versatility of intramolecularly positioned Lewis acids for otherwise challenging chemical transformations.

Conflict of Interests

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available in the supplementary material of this article.

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