One‐Pot Suzuki/Heck Sequence for the Synthesis of (E)‐Stilbenes Featuring a Recyclable Silica‐Supported Palladium Catalyst via a Multi‐Component Reaction in 1,3‐Propanediol

The synthesis of (E)‐stilbenes was performed following a one‐pot Suzuki/Heck sequence through the use of potassium vinyltrifluoroborate. The combination of heterogeneous palladium/silica (Pd/SiO2) catalyst with potassium phosphate monohydrate (K3PO4⋅H2O) as base resulted in useful to good isolated yields regardless of the ortho‐, meta‐ or para‐substitution of the aryl halides employed. In a sustainable approach, we found that bio‐sourced 1,3‐propanediol could advantageously replace N‐methylpyrrolidone (NMP) as similar yields were obtained. Moreover, the reactivity gap between aryl iodides and bromides resulting from the use of 1,3‐propanediol allowed an efficient multi‐component approach toward the synthesis of (E)‐stilbenes. Furthermore, this heterogeneous catalyst was found to be extremely robust despite the use of aerobic conditions and was successfully re‐used over several cycles.