Oxidative Addition of C–H Acids to bis (1,5-cyclooctadiene) Ni(0)Ni(COD) 2 Complex

The paramagnetic Ni(I) complexes and the products of their reactions with ethylene in catalytic systems based on the Ni(COD) 2 , Ni(PPh 3 ) 4 complexes and C–H acids (β-diketones, 1,3-cyclopentadiene) have been identified. It is assumed that the Ni(COD) 2 and Ni(PPh 3 ) 4 reactions with these C–H acids occur with the oxidation of Ni(0) to Ni(II) as a result of the oxidative addition of β-diketone (1,3-cyclopentadiene) to Ni(COD) 2 or Ni(PPh 3 ) 4 in the first stage and the disproportionation of Ni(II) + Ni(0) ↔ 2Ni(I) with the formation of paramagnetic complexes of monovalent nickel at the second stage.