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

Abstract

Joucla, Lionel Cusati, Giuseppe Pinel, Catherine Djakovitch, LaurentThe 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 (K3PO4H2O) 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-methyl-pyrrolidone (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 he extremely robust despite the use of aerobic conditions and was successfully re-used over several cycles

Polyvinylpyridine-Supported Palladium Nanoparticles: An Efficient Catalyst for Suzuki–Miyaura Coupling Reactions

“…Moreover, they can directly undergo transmetalation with the arylboronic due to the enhancement of the electron density of palladium. These results agree with evidence previously reported by other authors on the beneficial effect of the oxygen [43,[49][50][51][52]. The observed increase in catalytic activity has been ascribed to the formation of oxidized Pd species onto the surface of Pd NPs.…”

Silica‐Supported Molecular Catalysts for Tandem Reactions

“…Besides the use of these SiO 2 ‐supported Au catalysts, palladium nanoparticles were also applied in the construction of the SiO 2 ‐supported Pd catalysts for tandem reactions. The Djakovitch group reported a SiO 2 ‐supported Pd catalyst (Pd/SiO 2 ) using the same wet impregnation method, in which the palladium nanoparticles were impregnated into commercially available silica (Aerosil 200/Degussa). The combination of the Pd/SiO 2 catalyst and potassium phosphate monohydrate (K 3 PO 4 ⋅H 2 O) resulted in the efficient preparations of ( E )‐stilbenes in the tandem Suzuki/Heck reactions (Scheme ).…”

“…The Djako- Scheme3.Alaser-drivent andem oxidation/amidation reaction using the Au/SiO 2 catalyst. ChemCatChem 2018ChemCatChem , 10,1739ChemCatChem -1752 www.chemcatchem.org 2018 Wiley-VCH Verlag GmbH &Co. KGaA, Weinheim vitch group [46] reported aS iO 2 -supported Pd catalyst( Pd/SiO 2 ) using the same wet impregnation method,i nw hich the palladium nanoparticles were impregnatedi nto commercially available silica (Aerosil2 00/Degussa). The combination of the Pd/ SiO 2 catalysta nd potassium phosphate monohydrate (K 3 PO 4 ·H 2 O) resulted in the efficient preparations of (E)-stilbenes in the tandemS uzuki/Heck reactions (Scheme 5).…”

Suzuki Coupling Reactions Catalyzed by PdO Dispersed on Dealuminated Y Zeolite in Air under Ambient Conditions

“…PdO has been applied to other types of coupling reactions 10. Moreover, Joucla et al synthesized ( E )‐stilbenes from chloroiodobenzenes using sequential one‐pot Suzuki–Miyaura and Heck reactions using Pd/C or Pd/SiO 2 11. Under such conditions, a significant improvement might be achieved using highly dispersed PdO as the catalyst.…”