Recycling of homogeneous catalysts in reactive ionic liquid – solvent-free aminofunctionalizations of alkenes

Abstract

Turning down the bed for homogenous catalysts: the use of dimcarb as a reactive ionic liquid, offers the opportunity to carry out different homogeneously transition metal catalyzed aminations without using any solvent, while at the same time efficient catalyst recycling is possible.

The Telomerization of 1,3‐Dienes – A Reaction Grows Up

“…Another example for the use of ionic liquids to recycle the catalyst is dimcarb as a reactive ionic liquid . Dimcarb is the CO 2 ‐adduct of two dimethylamine molecules, resulting in a liquid that predominantly exists in the ionic form ,.…”

Homogeneously Catalyzed 1,3‐Diene Functionalization – A Success Story from Laboratory to Miniplant Scale

“…After extraction of the product mixture with cyclohexane, the catalyst phase was reused in 30 recycling runs without any loss of activity. Overall, a turnover number of the palladium catalyst higher than 90,000 was achieved, which tackles the range of homogeneous catalysts in industrial applications …”

“…Another concept of catalyst immobilization developed by our group for hydroamination is feasible by applying dimethyl ammonium dimethyl carbamate (DIMCARB, vide supra) both, as nucleophile and as polar solvent. Following the same perception as for butadiene telomerization, hydroamination of β ‐myrcene is also successful . With 1,4‐bis (diphenylphosphino) butane‐tetra‐sulfonate as ligand and a Pd‐precursor, the corresponding dimethyl terpenyl amines were synthesized in an average of 72 % over four successive recycling runs.…”

“…Overall, a turnover number of the palladium catalyst higher than 90,000 was achieved, which tackles the range of homogeneous catalysts in industrial applications. [31] A very potent substrate for the telomerization of butadiene besides alcohols is carbon dioxide. The application of this C1building block is of particular interest because the telomerization of butadiene with CO 2 yields a d-lactone, which can be used as a chemical for the synthesis of various products by means of further homogeneously catalyzed functionalization reactions ( Figure 14).…”

“…Following the same perception as for butadiene telomerization, hydroamination of bmyrcene is also successful. [31] With 1,4-bis (diphenylphosphino) butane-tetra-sulfonate as ligand and a Pd-precursor, the corresponding dimethyl terpenyl amines were synthesized in an average of 72 % over four successive recycling runs. Notably, phase separation between the pure product and the catalyst containing DIMCARB phase occurred at room temperature without the need for an extraction solvent.…”