Hydroformylation of 1-hexene with rhodium in non-aqueous ionic liquids : how to design the solvent and the ligand to the reaction

Metathesis of 1‐Octene in Ionic Liquids and Other Solvents: Effects of Substrate Solubility, Solvent Polarity and Impurities

“…NAlkylpyridinium-based ionic liquids seem to possess similar solubilities as 1-alkyl-3-methylimidazolium melts with the same alkyl substituent. Literature data of the solubilities for 1-hexene [36] and 1-octene [37] are in good agreement, with 1-hexene being, as expected, slightly better soluble than 1-octene.…”

“…Very little solubility data for alkene substrates in ionic liquids are available at present in the literature, [35][36][37] and therefore the solubility of 1-octene in ionic liquids was determined by gas chromatography (see Supporting Information). For ionic liquids based on the same cation the solubility increases the order…”

Triphasic Liquid Systems for Improved Separations. Trioctylmethylammonium Chloride‐Immobilised Rhodium Trichloride: A Phosphine‐Free Hydroformylation Catalytic System

“…[5] Ionic liquids have attracted attention in this field as well, due to their combined ability to form biphasic systems with organic species, and to retain catalytic metal complexes. [6] More recently, hydroformylation techniques based on the heterogenisation of the catalytic species using supported ionic liquid catalysis (SILP) have also been described, [7] along the lines of the supported aqueous phase catalysis (SAPC) developed earlier by Davis. [8] Leitner and co-workers have instead addressed the separation issue through the design of a CO 2 -regulated reaction/separation systems where the substitution at the metal catalyst makes it soluble during the hydroformylation reaction, and insoluble in the separation stage.…”

Recyclable Copper Catalysts Based on Imidazolium‐Tagged Bis(oxazolines): A Marked Enhancement in Rate and Enantioselectivity for Diels–Alder Reactions in Ionic Liquid

“…For asymmetric transformations using copper(II) complexes of bis(oxazolines) and aza-bis(oxazolines), extraction of the ligand is particularly problematic since the copper precursor remaining in the ionic liquid catalyses the background reaction and causes a reduction in the enantioselectivity. [12] In other ionic liquid systems, this problem has been addressed with varying levels of success by either designing new cationic ligands to increase the solubility of the catalyst and/or ligand in the ionic liquid [15] or by incorporating an imidazolium salt into the ligand to afford a "task-specific" ionic liquid, [16] two examples of which are illustrated in Scheme 1. In this latter approach a ligand is modified with an imidazolium group located remotely from the coordinating atoms (and hence the active site) such that the catalyst becomes an integral part of the ionic liquid and is retained during extraction.…”