Fig. 1. (A) Simplified cross-coupling mechanism, highlighting oxidative addition as the rate and/or selectivity determining step. (B) Competition experiment approach to determining relative rates of oxidative addition by quantifying ratios of Pd(ii) products via31P NMR spectroscopy. (C) Relative reactivity scale for oxidative addition to Pd(PCy3)2 for selected substrates; observed ΔG‡OA for 2-bromo-5-nitropyridine set to 0 kJ mol−1. (D) Utility of reactivity model in predictions for cross-coupling in synthesis.
