Recycling of Phosphorus-Based Organocatalysts by Organic Solvent Nanofiltration

• Published in: ACS sustainable chemistry & engineering Vol. 3; no. 11; pp. 2817 - 2822
• Main Authors: Großeheilmann, Julia, Büttner, Hendrik, Kohrt, Christina, Kragl, Udo, Werner, Thomas
• Format: Journal Article
• Language: English
• Published: American Chemical Society 02-11-2015
• Subjects: Membrane; Catalyst recycling; Organocatalysis; Homogeneous catalysis; Organic solvent nanofiltration (OSN)
• ISSN: 2168-0485; 2168-0485
• DOI: 10.1021/acssuschemeng.5b00734

Organic solvent nanofiltration has been studied as an efficient and mild tool for the separation of phosphorus-based organocatalysts and their subsequent recycling. The atom-economic conversion of butylene oxide with carbon dioxide has been chosen as a test reaction, yielding the desired cyclic carbonate in excellent yields under mild conditions. The utilization of modern solvent-resistant membranes to separate and recycle the organocatalyst from reaction media was established. Commercially available membranes with molecular weight cut-offs between 150 and 500 g·mol–1 were employed. DuraMem 300 proved to be the best membrane, showing excellent rejections of up to 99% for the organocatalyst in the recycling experiments. The catalyst and the membrane were reused in four consecutive reactions without the loss of activity and selectivity, respectively.