C-C bond formation strategy through ecocatalysis: Insights from structural studies and synthetic potential

We report the elaboration of novel bio-sourced ecocatalysts for Heck and Suzuki cross-coupling reactions.Ecocatalysis is based on the recycling of metals issued from phytoremediation or rehabilitation, and aninnovative chemical valorization of the subsequent biomass in the field of catalysis. Here, we describe theefficient palladium accumulation by plants (Brassica juncea, Lolium multiflorum) via rhizofiltration. Takingadvantage of the remarkable ability of the selected plants to accumulate Pd(II) species into their roots,these latter can be directly used for the preparation of ecocatalysts, called Eco-Pd®. The formed Eco-Pd®catalysts are thoroughly characterized via ICP-MS, XRD, XPS, TEM, SEM in order to elucidate the chemicalcomposition and morphology of the formed materials. Significant differences to conventional Pd-basedcatalysts such as palladium(II) chloride can principally be related to a particular Lewis acid behavior ofthe Eco-Pd®catalysts. Finally, the obtained Eco-Pd®appear as highly active catalysts in Heck and Suzukicross-coupling reactions necessitating considerably lower Pd quantity compared to precedently reportedbio-sourced palladium containing catalysts.