Cationic phosphine ligands with phenylguanidinium modified xanthene moieties—a successful concept for highly regioselective, biphasic hydroformylation of oct-1-ene in hexafluorophosphate ionic liquids

Abstract

New guanidinium-modified diphosphine ligands with a xanthene backbone show high overall activity and high regioselectivity in the biphasic hydroformylation of oct-1-ene using hexafluorophosphate ionic liquids.

Carbon Monoxide as a Chemical Feedstock: Carbonylation Catalysis

“…The solubility was increased easily by adding alkyl chains R 1 and R 2 to ligand 35 to give 36, which did not deteriorate the catalytic performance. Compared to other wide-bite-angle diphosphine ligands, Xantphos-type ligands can be modified easily while retaining there favorable properties, especially in hydroformylation, and as a result many derivatives have been synthesized and used in fluorous-phase hydroformylation catalysis [72], aqueous-phase catalysis [73,74], one-phase hydroformylation and catalyst extraction [75], catalysis in ionic liquids [76,77], hydroformylation with immobilized catalysts [78,79], and catalysis in supercritical CO 2 [80].…”

Catalytic SILP Materials

“…Apart from the fact that the ionic liquid covers the more or less undefined surface of the support to enhance uniformity of the material, the concept makes use of the fact that ionic liquids have been found in many studies to be highly suitable solvents for transition metal catalyzed reactions [11][12][13][14][15]. The almost unlimited combinations of cation and anion further allow the synthesis of tailor made ionic liquids that can stabilize the catalytic species [16][17][18]. Traditionally, ionic liquids have been used in transition metal-catalyzed reactions using liquid-liquid systems comprising an ionic liquid and an immiscible organic solvent.…”

Recent Advances in Continuous Rhodium-Catalyzed Hydroformylation

“…However, for higher olefins, reaction rates are often limited by the insolubility of the lipophilic substrate in the catalyst phase. Alternative approaches to aqueous biphasic and SAP catalysis include ionic liquid-phase hydroformylation [40,41], and supported ionic liquid-phase (SILP) hydroformylation [42]. The latter system was established by Mehnert's team in ExxonMobil, by forming a fixed-bed reactor utilizing Rh-phosphine complexes dissolved in a silica-supported ionic liquid film (Figure 12).…”