Monolithic polymer/carrier materials: Versatile composites for fine chemical synthesis

Sol‐Gel and Porous Glass‐Based Silica Monoliths with Hierarchical Pore Structure for Solid‐Liquid Catalysis

“…Compared with established solid-gas and solid-liquid-gas processings, the rational preparation of monoliths for solid-liquid catalysis, particularly for the production of pharmaceuticals and fine chemicals, is emerging from a niche for low-temperature processes with liquid-phase reactants [2,9,12,44,45]. For operation with a liquid mobile phase, the millimeter-sized channels in Fig.…”

A Palladium Wall Coated Microcapillary Reactor for Use in Continuous Flow Transfer Hydrogenation

“…Similar procedures, stabilising Pd particles with quaternary ammonium salts have been reported by Reetz et al [31,32] All steps except the silylation step were carried out at room temperature and were followed by a short washing protocol. This procedure presents a modification of previous protocols, [11,18] which were used for the immobilisation of Pd on monolithic structures.…”

“…The general procedure was modified from previous protocols for immobilising Pd within monolithic structures or on beads. [11,15,[18][19][20] The reactor system presented herein contrasts traditional polystyrene or silica solid sup-ports, which have a granular, bead or gel form, [7,[20][21][22][23][24] as it consists of multiple capillaries manufactured from ethylene-vinyl alcohol (EVOH). The capillary geometry provides a known flow profile, which can be easily characterised and modelled, and does not suffer from channelling problems that are typically observed in packed bed systems.…”

Reproducibility and Scalability of Microwave-Assisted Reactions

“…Moreover, the immobilized catalysts could be used over several cycles without a significant drop in activity. Kappe described a Heck cross-coupling reaction using a continuous-flow reactor based on a megaporous glass carrier material with suitable polymer functionalization introduced into the pore volume of this support (Kunz et al, 2005). For this purpose, a basic ion-exchange resin-loaded monolith was used in order to create the close neighbourhood of ionic sites and Pd(0) sites (Scheme 18).…”