Reductive Etherification of Fatty Acids or Esters with Alcohols using Molecular Hydrogen

Abstract

In the presence of a catalyst system consisting of a ruthenium/triphos complex and the Brønsted acid trifluoromethanesulfonimide, mixtures of fatty acids and aliphatic alcohols are converted into the corresponding ethers at 70 bar H2 . The protocol allows the sustainable one-step synthesis of valuable long-chain ether fragrances, lubricants, and surfactants from renewable sources. The reaction protocol is extended to various fatty acids and esters both in pure form and as mixtures, for example, tall oil acids or rapeseed methyl ester (RME). Even the mixed triglyceride rapeseed oil was converted in one step.

Synthesis of Biomass‐Derived Ethers for Use as Fuels and Lubricants

“…The etherification of glycerol is also discussed briefly because several recent reviews have discussed glycerol conversion to ethers, solketal, acrolein, propylene glycol, polymers, propanediols, glycerol oxidation products, fuel additives, and other value‐added products . Williamson ether synthesis and other homogeneous routes are not discussed as these processes require catalyst separation and produce salts . Instead, we focus exclusively on the use of heterogeneous catalysts due to their ease of separation from products.…”

“…[31,[36][37][38] Williamson ether synthesis and other homogeneousr outes are not discussed as these processes requirec atalyst separation and produce salts. [19,39] Instead, we focus exclusively on the use of heterogeneous catalysts due to their easeo fseparation from products.…”

Carbon/Silicon Exchange at the Apex of Diphos‐ and Triphos‐Derived Ligands – More Than Just a Substitute?

“…[27] Recent investigations showed the high potential of this ligand platform to act as a superior support in metal-catalyzed reactions of various substrates. [53][54][55][56][57][58][59][60][61][62][63][64][65][66][67][68] However, the concept of C/Si switch to alter the catalytic properties or the reactivity of the metal complexes was never comparatively reported for such catalytic transformations. While the stability of the Si species is indeed crucial, it will be interesting to see whether an influence of C/Si exchange can be observed for other systems.…”

“…Such changes are typically observed for Triphos and its Si‐derived counterpart Triphos Si for metals that have high‐spin and low‐spin states with only low energy barriers between the two states . Recent investigations showed the high potential of this ligand platform to act as a superior support in metal‐catalyzed reactions of various substrates . However, the concept of C/Si switch to alter the catalytic properties or the reactivity of the metal complexes was never comparatively reported for such catalytic transformations.…”

Homogeneous (De)hydrogenative Catalysis for Circular Chemistry – Using Waste as a Resource

“…Recently de Vries and co‐workers have reported an alternative strategy for the recycling of polyesters via catalytic hydrogenation (Scheme 8). [164] Authors utilized a ruthenium‐Triphos complex as they were earlier demonstrated for the direct reductive etherification of carboxylic acid esters to ethers [165,166] . Catalytic hydrogenation was performed using Ru(acac) 3 (1 mol%) precatalyst, Triphos ligand (1.5 mol%), and a Lewis acid as a cocatalyst.…”