Evidence for single metal two electron oxidative
addition and reductive elimination at uranium
Benedict M. Gardner
, Christos E. Kefalidis
, Erli Lu
, Dipti Patel
, Eric J.L. McInnes
, Floriana Tuna
Ashley J. Wooles
, Laurent Maron
& Stephen T. Liddle
Reversible single-metal two-electron oxidative addition and reductive elimination are com-
mon fundamental reactions for transition metals that underpin major catalytic transforma-
tions. However, these reactions have never been observed together in the f-block because
these metals exhibit irreversible one- or multi-electron oxidation or reduction reactions. Here
we report that azobenzene oxidises sterically and electronically unsaturated uranium(III)
complexes to afford a uranium(V)-imido complex in a reaction that satisﬁes all criteria of a
single-metal two-electron oxidative addition. Thermolysis of this complex promotes extrusion
of azobenzene, where H-/D-isotopic labelling ﬁnds no isotopomer cross-over and the non-
reactivity of a nitrene-trap suggests that nitrenes are not generated and thus a reductive
elimination has occurred. Though not optimally balanced in this case, this work presents
evidence that classical d-block redox chemistry can be performed reversibly by f-block
metals, and that uranium can thus mimic elementary transition metal reactivity, which may
lead to the discovery of new f-block catalysis.
School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
LPCNO, CNRS & INSA, Université Paul Sabatier, 135 Avenue
de Rangueil, Toulouse 31077, France.
School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
EPSRC National UK EPR
Facility, School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK. Benedict M. Gardner,
Christos E. Kefalidis, Erli Lu and Dipti Patel contributed equally to this work. Correspondence and requests for materials should be addressed to
L.M. (email: email@example.com) or to S.T.L. (email: firstname.lastname@example.org)