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Samarium diiodide (SmI₂) is a privileged, single-electron reductant deployed in diverse synthetic settings. However, generalizable methods for catalytic turnover remain elusive because of the well-known challenge associated with cleaving strong Sm^III–O bonds. Prior efforts have focused on the use of highly reactive oxophiles to enable catalyst turnover. However, such approaches give rise to complex catalyst speciation and intrinsically limit the synthetic scope. Herein, we leveraged a mild and selective protonolysis strategy to achieve samarium-catalyzed, intermolecular reductive cross-coupling of ketones and acrylates with broad scope. The modularity of our approach allows rational control of selectivity based on solvent, pK_a(whereK_ais the acid dissociation constant), and the samarium coordination sphere and provides a basis for future developments in catalytic and electrocatalytic lanthanide chemistry.

Half‐sandwich rhodium monohydrides are often proposed as intermediates in catalysis, but little is known regarding the redox‐induced reactivity accessible to these species. Herein, the bis(diphenylphosphino)ferrocene (dppf) ligand has been used to explore the reactivity that can be induced when a [Cp*Rh] monohydride undergoes remote (dppf‐centered) oxidation by 1e⁻. Chemical and electrochemical studies show that one‐electron redox chemistry is accessible to Cp*Rh(dppf), including a unique quasi‐reversible Rh^II/Iprocess at −0.96 V vs. ferrocenium/ferrocene (Fc^+/0). This redox manifold was confirmed by isolation of an uncommon Rh^IIspecies, [Cp*Rh(dppf)]⁺, that was characterized by electron paramagnetic resonance (EPR) spectroscopy. Protonation of Cp*Rh(dppf) with anilinium triflate yielded an isolable and inert monohydride, [Cp*Rh(dppf)H]⁺, and this species was found to undergo a quasireversible electrochemical oxidation at +0.41 V vs. Fc^+/0that corresponds to iron‐centered oxidation in the dppf backbone. Thermochemical analysis predicts that this dppf‐centered oxidation drives a dramatic increase in acidity of the Rh−H moiety by 23 pK_aunits, a reactivity pattern confirmed by in situ¹H NMR studies. Taken together, these results show that remote oxidation can effectively induce M−H activation and suggest that ligand‐centered redox activity could be an attractive feature for the design of new systems relying on hydride intermediates.