Heterogeneously Pd/C catalysed procedure for the vinylation of aryl bromides Original Research Article

Heterogeneous Pd/C catalyst was applied to the Suzuki–Miyaura vinylation of various aryl and heteroaryl halides under aerobic and mild reaction conditions [1.0 mmol aryl halide, 1.5 mmol potassium vinyltrifluoroborate, 3.0 mmol K3PO4·H2O, 0.1 mol% Pd/C(EVO), 1 mL NMP, 100 °C, 24 h]. Useful isolated yields (57–73%) were achieved. In some cases, the catalytic system should be tuned to face the reactivity of the aryl halides: while 0.1 mol% Pd/C is sufficient for almost all aryl bromides, 1.0 mol% Pd/C was used for free phenols.The heterogeneous catalyst was proved to be stable upon several catalytic cycles; however, the results showed that this was dependent on addition of the base. Hot-filtration experiment indicates that the activity was mainly due to leached Pd-species, indicating that the Pd/C catalyst acts as a palladium reservoir.