C−H and C−CN Bond Activation of Acetonitrile and Succinonitrile by [Tp′Rh(PR3)

Abstract

The [Tp′Rh(PR3)] fragments, where Tp′ = tris(3,5-dimethylpyrazolyl)borate, R3 = Me3 (a) or PhMe2 (b), were shown to be applicable for the activation of the C−H and C−CN bonds of acetonitrile. The photoirradiation of Tp′Rh(PR3)H2 (1a,b) in acetonitrile at room temperature afforded the complexes Tp′Rh(PR3)(CH2CN)H (3a,b), by the selective oxidative addition of the primary C−H bond of acetonitrile to the [Tp′Rh(PR3)] fragment generated by the dehydrogenation of 1. The thermal reactions of Tp′Rh(PMe3)(Ph)H (2a) or Tp′Rh(κ2-C6H4-2-PMe2)H (2b) in acetonitrile at 80 °C also resulted in the formation of 3a and 3b, respectively, by the oxidative addition of the C−H bond to the [Tp′Rh(PR3)] fragment, generated by the reductive elimination of benzene (from 2a) or intramolecular reductive elimination of the PPhMe2 ligand (from 2b). Heating the isolated C−H bond activated complexes 3a,b in acetonitrile at higher temperature (100 °C) for longer times (≈5 days) resulted in the formation of the corresponding C−CN bond ac...