ChemInform Abstract: Donor‐Stabilized Phosphenium Adducts as New Efficient and Immobilizing Ligands in Palladium‐Catalyzed Alkynylation and Platinum‐Catalyzed Hydrogenation in Ionic Liquids.

Abstract

Catalysis O 0020Donor-Stabilized Phosphenium Adducts as New Efficient and Immobilizing Ligands in Palladium-Catalyzed Alkynylation and Platinum-Catalyzed Hydrogenation in Ionic Liquids. -Donor-stabilized phosphenium salts are successfully applied as ligands in the Pd-catalyzed Heck arylation of terminal alkyne (II) with aryl bromides. Best results are achieved for the ligand (DFIP) bearing two electron-withdrawing furyl groups. The recyclability, however, is limited due to protonation of the C-P bond of the ligand under acidic conditions. In contrast, the complex formed from PtCl2 and the diphenylphosphenium ligand (DPIP) shows excellent stability and chemoselectivity in the hydrogenation of m-chloronitrobenzene (IV). It can be recycled and reused for at least seven runs without significant loss of activity or chemoselectivity. -(SALEH, S.; FAYAD, E.; AZOURI, M.; HIERSO*, J.-C.; ANDRIEU, J.; PICQUET, M.; Adv. Synth. Catal. 351 (2009) 10, 1621-1628; Inst. Chim. Mol., Univ. Bourgogne, F-21078 Dijon, Fr.; Eng.) -Mischke 49-025