Abstract

The utility of transition metal hydride catalyzed hydrogen atom transfer (MHAT) has been widely demonstrated in organic transformations such as alkene isomerization and hydro functionalization reactions. However, the highly reactive nature of the hydride and radical intermediates has hindered mechanistic insight into this pivotal reaction. Recent advances in electrochemical MHAT have opened up the possibility for new analytical approaches for mechanistic diagnosis. Here, we report a voltametric interrogation of Co-Based MHAT reactivity, describing in detail the oxidative formation and reactivity of the key Co-H intermediate and its reaction with aryl alkenes. Insights from cyclic voltammetry and finite element simulations help elucidate the rate-limiting step as metal hydride formation, which we show to be widely tunable based on ligand design. Voltammetry is also suggestive of the formation of Co-alkyl intermediates and a dynamic equilibrium with the reactive neutral radical. These mechanistic studies provide information for the design of future hydro functionalization reactions, such as catalyst and silane choice, the relative stability of metal-alkyl species, and how hydro functionalization reactions utilize Co-alkyl intermediates. in summary, these studies establish an important template for studying MHAT reactions from the perspective of electrochemical kinetic frameworks.

Department(s)

Chemistry

Comments

National Science Foundation, Grant 1747505

International Standard Serial Number (ISSN)

1520-5126; 0002-7863

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2025 American Chemical Society, All rights reserved.

Publication Date

16 Aug 2023

PubMed ID

37530748

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Chemistry Commons

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