Catalytic Hydrogenolysis of Substituted Diaryl Ethers by Using Ruthenium Nanoparticles on an Acidic Supported Ionic Liquid Phase (Ru@SILP-SO3H)

Abstract

Catalytic hydrogenolysis of diaryl ethers is achieved by using ruthenium nanoparticles immobilized on an acidic supported ionic liquid phase (Ru@SILP-SO3H) as a multifunctional catalyst. The catalyst components are assembled through a molecular approach ensuring synergistic action of the metal and acid functions. The resulting catalyst is highly active for the hydrogenolysis of various diaryl ethers. For symmetric substrates such as diphenyl ether, hydrogenolysis is followed by full hydrodeoxygenation producing the corresponding cycloalkanes as the main products. For unsymmetric substrates, the cleavage of the C–O bond is regioselective and occurs adjacent to the unsubstituted phenyl ring. As hydrogenation of benzene is faster than hydrodeoxygenation over the Ru@SILP-SO3H catalyst, controlled mixtures of cyclohexane and substituted phenols are accessible with good selectivity. Application of Ru@SILP-SO3H catalyst in continuous-flow hydrogenolysis of 2-methoxy-4-methylphenoxybenzene is demonstrated with use of commercial equipment.

Organometallic Synthesis of Bimetallic Cobalt‐Rhodium Nanoparticles in Supported Ionic Liquid Phases (CoxRh100−x@SILP) as Catalysts for the Selective Hydrogenation of Multifunctional Aromatic Substrates

“…In this context, the immobilization of metal NPs on supported ionic liquid phases (SILP) has emerged as a versatile molecular approach to producing multifunctional catalytic systems with tailored reactivity. [ 10 ] Recent studies have shown that SILPs provide suitable matrices for the synthesis and stabilization of monometallic and bimetallic NPs, producing catalytic systems possessing excellent properties for hydrogenation, [ 11 ] hydrodeoxygenation, [ 12 ] and hydrogenolysis [ 13 ] reactions. For example, bimetallic FeRu NPs immobilized on an imidazolium‐based SILP have shown interesting reactivity for the selective hydrogenation of non‐aromatic CC and CO bonds while showing no activity toward aromatic rings.…”

Selectivity control in hydrogenation through adaptive catalysis using ruthenium nanoparticles on a CO2-responsive support

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ith the transition from fossil resources to a chemical value chain based on renewable energy and carbon resources, the development of new catalytic technologies to cope with the diversity and variation of feedstock quality is of crucial importance [1][2][3][4][5][6][7][8] . Extensive efforts are currently dedicated to the development of multifunctional catalytic systems able to achieve selective hydrogenation reactions of biomass-derived substrates and intermediates [9][10][11][12][13][14][15][16][17][18][19][20][21] . Although many of these catalysts present outstanding properties regarding their dedicated tasks, their performance is typically optimized for static operation under precisely defined parameters.

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Metal Nanoparticles Immobilized on Molecularly Modified Surfaces: Versatile Catalytic Systems for Controlled Hydrogenation and Hydrogenolysis

“… 46 Recently, we further illustrated the versatility of Ru@SILP-SO 3 H through its application in selective hydrogenolysis of various substituted diaryl ethers. 48 The presence of the strong acid sites in combination with the Ru NPs was found to be the key to high ether bond cleavage activity. In several of these reactions, the Ru@SILP-SO 3 H material was used for several hours under continuous flow conditions without leaching of the active phase or growth of the Ru NPs, highlighting its stability.…”

“…In several of these reactions, the Ru@SILP-SO 3 H material was used for several hours under continuous flow conditions without leaching of the active phase or growth of the Ru NPs, highlighting its stability. 46 − 48 …”