Relevance of Single-Transmetalated Resting States in Iron-Mediated Cross-Couplings: Unexpected Role of σ-Donating Additives

Lidie Rousseau (1) , Nadia Touati (2) , Laurent Binet (2) , Pierre Thuéry (3) , Guillaume Lefèvre (1)

1 CSB2D - Catalysis, Synthesis of Biomolecules and Sustainable Development
2 PCMTH - Physicochimie des Matériaux Témoins de l’Histoire (partenariat Chimie ParisTech et C2RMF)
3 LCMCE - Laboratoire de Chimie Moléculaire et de Catalyse pour l'Energie (ex LCCEF)

Control of the transmetalation degree of organoiron(II) species is a critical parameter in numerous Fe-catalyzed cross-couplings to ensure the success of the process. In this report, we however demonstrate that the selective formation of a monotransmetalated FeII species during the catalytic regime counterintuitively does not alone ensure an efficient suppression of the nucleophile homocoupling side reaction. It is conversely shown that a fine control of the transmetalation degree of the transient FeIII intermediates obtained after the activation of alkyl electrophiles by a single-electron transfer (SET), achievable using σ-donating additives, accounts for the selectivity of the cross-coupling pathway. This report shows for the first time that both coordination spheres of FeII resting states and FeIII short-lived intermediates must be efficiently tuned during the catalytic regime to ensure high coupling selectivities.

Domains: Chemical Sciences; Coordination chemistry

Lidie Rousseau, Nadia Touati, Laurent Binet, Pierre Thuéry, Guillaume Lefèvre. Relevance of Single-Transmetalated Resting States in Iron-Mediated Cross-Couplings: Unexpected Role of σ-Donating Additives. Inorganic Chemistry, In press, 60 (11), pp.7991-7997. ⟨10.1021/acs.inorgchem.1c00518⟩. ⟨cea-03228273⟩