Homogeneous Catalysis at its Edge: High‐Temperature Ru‐Catalysed Amination of Alcohols under Continuous Flow Conditions

Homogeneous Catalysis Homogeneous Catalysis

Continuous-flow homogeneous catalysis using the temperature-controlled solvent properties of supercritical carbon dioxide.

A fully integrated continuous process for homogeneous catalysed reactions in scCO(2) has been developed exploiting the tunable solvent properties of scCO(2). A heated condenser situated above the reaction zone leads to a phase split under isobaric conditions resulting in efficient catalyst retention and recirculation. Continuous isomerisation of allylic alcohols was carried out for over 200 hou...

Solid-phase peptide synthesis under continuous-flow conditions.

A system is described for solid-phase synthesis of peptides under continuous-flow conditions with liquid chromatographic equipment, conventional polystyrene supports, and well-defined chemistry. The model tetrapeptide Leu-Ala-Gly-Val was assembled in 99.3% purity in about 4 hr on microporous copoly(styrene-1% divinylbenzene). During coupling, the preformed symmetric anhydrides were conserved by...

The Eschenmoser coupling reaction under continuous-flow conditions

The Eschenmoser coupling is a useful carbon-carbon bond forming reaction which has been used in various different synthesis strategies. The reaction proceeds smoothly if S-alkylated ternary thioamides or thiolactames are used. In the case of S-alkylated secondary thioamides or thiolactames, the Eschenmoser coupling needs prolonged reaction times and elevated temperatures to deliver valuable yie...

Molecular weight enlargement--a molecular approach to continuous homogeneous catalysis.

Molecular weight enlargement (MWE) is an attractive method for homogeneous catalyst recycling. Applications of MWE in combination with either catalyst precipitation or nanofiltration have demonstrated their great potential as a method for process intensification in homogeneous catalysis. Selected, recent advances in MWE in combination with catalyst recovery are discussed, together with their im...