Successful chemical production of molecules whilst simultaneously reducing the environmental impact of the process relies not only on more efficient reactions but also on developments in reactor and separation technology. Recent decades have also witnessed a significant growth in industrial interest in solvent based separations using membranes stable to organic solvents. The incorporation of membranes in to a chemical process can be via a simple downstream processing method or an integrated reaction membrane method. This paper deals with homogeneous organometallic catalysed reactions and probes the separation of a number of readily available Palladium complexes from reaction mixtures with highly stable ceramic membranes. A number of different processing methods namely on-line, at-line and off-line are compared and contrasted. High rejection of Palladium species and consequently very low Palladium contamination of reaction products with a single organic solvent nanofiltration (OSN) step has been demonstrated.

Cyclic peptides have found numerous and wide ranging applications that include drug molecules, nanomaterials, and chiral chromatography stationary phases. However, in the crucial cyclization step, high dilution conditions are often required, resulting in large volumes of solvent being consumed to prepare relatively small quantities of product. This paper demonstrates the synthesis of a cyclic nonapeptide with in-line solvent recycling via organic solvent nanofiltration (OSN) resulting in a significant reduction in the solvent load of the reaction and concomitant improvement in process mass intensification (PMI). The membrane was used to remove the reaction product from the reaction vessel, as the cyclic peptide product shows limited stability in the presence of an excess of reaction reagent. In comparison to the standard batch reaction, no loss in yield or product purity was observed for the OSN process tested. The proof-of-concept study outlined in this paper was performed on a real active pharmaceutical ingredient (API), and the technique used is widely applicable and flexible.

Organic solvent nanofiltration (OSN) is gradually expanding from academic research to industrial implementation. The need for membranes with low and sharp molecular weight cutoffs that are able to operate under aggressive OSN conditions is increasing. However, the lack of comparable and uniform performance data frustrates the screening and membrane selection for processes. Here, a collaboration is presented between several academic and industrial partners analyzing the separation performance of 10 different membranes using three model process mixtures. Membrane materials range from classic polymeric and thin film composites (TFCs) to hybrid ceramic types. The model solutions were chosen to mimic cases relevant to today's industrial use: relatively low molar mass solutes (330-550 Da) in n-heptane, toluene, and anisole.

The synthesis of a 1‐aryltetralin privileged structure‐based library of novel angular heterocyclic lignans is described. Indolotetralins 3, tetrahydroquinolinotetralins 4, and thiochromanotetralins 5 were obtained from the methyl ester of thuriferic acid 2 according to a three‐step procedure involving an InCl3‐catalyzed Friedel–Crafts‐type cyclization as the key step.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)