Dependences of the initial rate on amide concentration in the presence and absence of 2 equiv. of exogenous base Na2CO3. The curve fit results from a nonlinear least-squares fit to a hyperbolic function of [4]. Conditions: [(IMes)Pd(TFA)2(H2O)] = 2 mM, [4] = 0 – 0.24 M, 4.0 ml of toluene, initial pO2 = 700 torr, 80 °C. In the experiments with added base, 0.2 – 1.6 mmol Na2CO3 was used.