Mono- and double carbonylation of iodobenzene in the presence of reusable supported palladium catalysts

Abstract

Various silica-supported palladium catalysts were prepared and tested in the carbonylation of aryl iodides in the presence of aliphatic amines and aniline. In the former reaction, the main products are the α-ketoamides, whereas monocarbonylation is favoured with aniline. Small modification of the support, of the palladium precursor, or of the conditions of immobilisation were found to affect considerably the outcome of the reactions and recyclability of the catalysts. Under optimum conditions, the phosphine-free palladium catalysts can be reused six to ten times without considerable loss of activity. By the proper selection of the solvent, the leaching of palladium into the reaction mixtures can be reduced considerably.

Application of γ‐Valerolactone as an Alternative Biomass‐Based Medium for Aminocarbonylation Reactions

“…Although aminocarbonylation reactions are routinely performed in conventional organic solvents such as N , N ‐dimethylformamide (DMF), toluene, 1,4‐dioxane, 2‐butanone, acetonitrile, and tetrahydrofuran (THF), DMF has been identified as the best medium for Pd‐catalyzed reactions. However, the toxicity of conventional solvents is significantly higher than the biomass‐based alternative γ‐valerolactone (Table ).…”

Solvent-free aminocarbonylation of iodobenzene in the presence of SILP-palladium catalysts

“…NMR spectra of isolated products correspond well to those reported previously. 6,7,17,20,22,32 a-Ketoamides formed as minor components were characterised using GC-MS.…”

“…It should be mentioned that in the absence of P-, As-, S-or Se-containing ligands the reactions were carried out at 5-9 bar CO pressure. [14][15][16] Selective double carbonylation took place at elevated CO pressure (30-40 bar) using bidentate phosphine ligands, 6 a polytitazane-Pd complex 18 and ionic liquids 19,20 supported on silica. To the best of our knowledge, the only example for a supported catalyst that can be used either in mono-or double carbonylation reactions leading to the selective formation amides and a-ketoamides, respectively, is a Pd-catalyst supported on a mesoporous poly-melamine-formaldehyde material.…”

Palladium nanoparticles on a pyridinium supported ionic liquid phase: a recyclable and low-leaching palladium catalyst for aminocarbonylation reactions

“…[32][33][34][35][36][37][38] Good stability, high porosity and easy modication of surface functional groups are the main features that make silica an ideal support for palladium catalysts. Silica with graed As-, 32,33 Se-, 34 and P-ligands [35][36][37] or silica-based supported ionic liquid phases (SILPs) with imidazolium [39][40][41][42][43][44] and phosphonium ions 45 were found to exert good stabilising effect to obtain recyclable catalysts for aminocarbonylation reactions.…”