Dependences of the initial rate on the initial oxygen pressure in the presence and absence of 2 equiv. of exogenous base Na2CO3. Conditions: [(IMes)Pd(TFA)2(H2O)] = 2.0 mM, [4] = 0.1 M, 4.0 ml of toluene, initial pO2 = 400 – 900 torr, 80 °C. In the measurement of pO2 dependence in the presence of base, 0.8 mmol Na2CO3 was used.