Continuous flow Negishi cross-couplings employing silica-supported Pd-PEPPSI-IPr precatalyst

The synthesis of a triethoxysilyl functionalised Pd-PEPPSI-IPr complex prepared via azide-alkyne cycloaddition is described. The complex was immobilised onto silica gel and applied as a heterogeneous catalyst in the Negishi reaction. The catalyst was active in both batch and continuous flow operation and was particularly effective for the coupling of heteroaryl chlorides. Long-term continuous flow experiments demonstrated good catalyst activity over fifteen hours.