Rhodium catalyzed hydrogenation reactions in aqueous micellar systems as green solvents

Abstract

The hydrogenation of itaconic acid and dimethyl itaconate is transferred from methanol to aqueous micellar solutions of several surfactants, e.g., SDS and Triton X-100, in order to facilitate the recovery of the catalyst. The reaction rate and selectivity strongly depends on the chosen surfactant and in some cases also on the surfactant concentration. In the best case the selectivity is the same as in methanol but the reaction rate is still lower because of a lower hydrogen solubility in water. Repetitive semi-batch experiments are chosen to demonstrate that high turn-over-numbers (.1000) can be reached in aqueous micellar solutions. No notable catalyst deactivation is observed in these experiments. The performance of micellar reaction systems is controlled by the partition coefficient of the substrates between the micelles and the continuous aqueous phase which can be predicted using the Conductor-like Screening Model for Real Solvents (COSMO-RS).

Microemulsion Systems with Rhodium Tris(3‐sulfophenyl)phosphine Trisodium Salt Complex for Product Isolation and Catalyst Recycling in the Hydrogenation of Dimethyl Itaconate

“…With the OP9.5EO system, an almost unaltered initial hydrogenation rate as a function of the initial DMI concentration was observed. This is an example of the inhibiting effect of the phenyl ring on the hydrogenation rate [15]. This effect was observed when using a high concentration of OP9.5EO (c = 0.13).…”

A framework for the modeling and optimization of process superstructures under uncertainty

“…For the recycling of the catalyst and overcoming mass transfer limitations two technologies are investigated in InPROMPT: liquid multiphase systems (LMS) and thermomorphic solvent systems (TSS). LMS employ the complex phase behavior of aqueous solutions of surfactants to reduce mass transfer limitations (Schwarze et al, 2011). TSS employ mixtures of polar and non-polar components that show biphasic behavior at low temperatures for separation and homogenous behavior at higher temperatures to achieve higher reaction rates (Behr et al, 2006).…”

Enantioselective hydrogenation of itaconic acid and its derivates with sol–gel immobilized Rh/BPPM catalysts

“…High enantioselectivities could be obtained for the hydrogenation of itaconic acid and its derivates in aqueous-micellar solution with different homogeneous rhodium catalysts [15,16]. Because of the use of surfactants or micelle forming agents, the catalysts could be recovered by micellar enhanced ultrafiltration as shown by Dwars et al [17].…”