Reusable Proline-Containing Bimetallic Pd–Ni(Co, Cu, Fe)–Pro/Al2O3 Catalysts for Suzuki Reaction in Water

Abstract

Bimetallic proline-containing composites Pd–Ni(Co, Cu, Fe)–Pro/Al2O3, due to the synergistic effect, exhibit high catalytic activity in the Suzuki reaction in aqueous media, which makes it possible to reduce the amount of expensive Pd to 10–2 mol %. New catalysts are easily regenerated from the reaction mixture and can be reused up to 5 times without losing activity.

Construction of Bulky Ligand Libraries by Ru(II)-Catalyzed P(III)-Assisted ortho-C-H Secondary Alkylation

Modification of commercially available biaryl monophosphine ligands via ruthenium^(II)-catalyzed P^(III)-directed-catalyzed ortho C-H secondary alkylation is described. The use of highly ring-strained norbornene as a secondary alkylating reagent is the key to this transformation. A series of highly bulky ligands with a norbornyl group were obtained in excellent yields. The modified ligands with secondary alkyl group outperformed common substituted phosphines in the Suzuki-Miyaura cross-coupling reaction at a ppm mole level of Pd catalyst.