Electrocatalytic Transfer Hydrogenation of 1-Octene with [(tBuPCP)Ir(H)(Cl)] and Water

22 November 2023, Version 2
This content is a preprint and has not undergone peer review at the time of posting.


Electrocatalytic hydrogenation of 1-octene as nonactivated model substrate with neutral water as H-donor is reported, using [(tBuPCP)Ir(H)(Cl)] (1) as the catalyst, to form octane with high faradaic efficiency (FE) of 96% and a kobs of 87 s–1. Cyclic voltammetry with 1 revealed that two subsequent reductions trigger the elimination of Cl– and afford the highly reactive anionic Ir(I) hydride complex [(tBuPCP)Ir(H)]– (2), a previously merely proposed intermediate for which we now report first experimental data by mass spectrometry. In absence of alkene, the stoichiometric electrolysis of 1 in THF with water selectively affords the Ir(III) dihydride complex [(tBuPCP)Ir(H)2] (3) in 88% FE from the reaction of 2 with H2O. Complex 3 then hydrogenates the alkene in classical fashion. The presented electro-hydrogenation works with extremely high FE, because the iridium hydrides are water stable, which prevents H2 formation. Even in strongly alkaline conditions (Bu4NOH added), the electro-hydrogenation of 1-octene with 1 also proceeds cleanly (FE = 89%), suggesting a highly robust process that may rely on H2O activation, reminiscent to transfer hydrogenation pathways, instead of classical H+ reduction


Electrocatalytic Hydrogenation
Pincer Complex

Supplementary materials

Supporting Information
Supporting information containing experimental details, synthesis procedures, relevant NMR data, additional electrochemical experiments and LIFDI-MS details.


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.