title: Efficient C-H Bond ActivationsviaO2Cleavage by a Dianionic Cobalt(II) Complex.
abstract: A dianionic, square planar cobalt(II) complex reacts with O2in the presence of acetonitrile to give a cyanomethylcobalt(III) complex formed by C-H bond cleavage. Interestingly, PhIO andp-tolylazide react similarly to give the same cyanomethylcobalt(III) complex. Competition studies with various hydrocarbon substrates indicate that the rate of C-H bond cleavage greatly depends on thepKa of the C-H bond, rather than on the C-H bond dissociation energy. Kinetic isotope experiments reveal a moderate KIE value ofca.3.5 using either O2or PhIO. The possible involvement of a cobalt(IV) oxo species in this chemistry is discussed.
authors: Department of Chemistry, University of California at Berkeley, Berkeley, California 94720-1460. tdtilley@berkeley.edu.
authors: Andy I
authors: AI
authors: Nguyen
authors: Department of Chemistry, Stanford University, Stanford, California 94305. edward.solomon@stanford.edu.
authors: Ryan G
authors: RG
authors: Hadt
authors: Department of Chemistry, Stanford University, Stanford, California 94305. edward.solomon@stanford.edu.
authors: Edward I
authors: EI
authors: Solomon
authors: Department of Chemistry, University of California at Berkeley, Berkeley, California 94720-1460. tdtilley@berkeley.edu.
authors: T Don
authors: TD
authors: Tilley