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

Abstract

With the advent of renewable carbon resources, multifunctional catalysts are becoming essential to hydrogenate selectively biomass-derived substrates and intermediates. However, the development of adaptive catalytic systems, that is, with reversibly adjustable reactivity, able to cope with the intermittence of renewable resources remains a challenge. Here, we report the preparation of a catalytic system designed to respond adaptively to feed gas composition in hydrogenation reactions. Ruthenium nanoparticles immobilized on amine-functionalized polymer-grafted silica act as active and stable catalysts for the hydrogenation of biomass-derived furfural acetone and related substrates. Hydrogenation of the carbonyl group is selectively switched on or off if pure H2 or a H2/CO2 mixture is used, respectively. The formation of alkylammonium formate species by the catalytic reaction of CO2 and H2 at the amine-functionalized support has been identified as the most likely molecular trigger for the selectivity switch. As this reaction is fully reversible, the catalyst performance responds almost in real time to the feed gas composition.

Controlling Chemoselectivity of Catalytic Hydroboration with Light

“…[3] These methods typically rely on varying a parameter such as catalyst, [4] ligand [5] or reagent. [6] As a non-invasive stimulus which offers excellent spatialtemporal control, light would be particularly attractive to control selectivity. [7] However, despite the rapidly growing interest in photochemical methods, light is still most often used to promote reactions that either take place very slowly, or cannot occur at all in the dark.…”

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

“…The synthetic potential of such controlled transformations can help to exploit the green chemistry principles for the existing chemical value chain as well as for novel biomass-derived product streams. ,,,,, Recently demonstrated examples that are very challenging to achieve with classical heterogeneous or homogeneous catalysts include the selective hydrogenation of bicyclic heteroaromatics, fluorinated aromatics, aryl ether cleavage, and hydrogenation and deoxygenation of side chains in aromatics. Most recently, it has been demonstrated that the introduction of reactive functional groups can open the path to adaptive catalytic systems enabling reversible control over their performance by applying external stimuli . The manifold opportunities arising from the emerging design criteria motivate future developments in this direction.…”

“…Most recently, it has been demonstrated that the introduction of reactive functional groups can open the path to adaptive catalytic systems enabling reversible control over their performance by applying external stimuli. 62 The manifold opportunities arising from the emerging design criteria motivate future developments in this direction.…”

Spotting Trends in Organocatalyzed and Other Organomediated (De)polymerizations and Polymer Functionalizations

“…[220] Angewandte Chemie Aufsätze redox catalysis, there are also other potentially metal-free approaches that may be investigated in the context of polymer upcycling. These could include organocatalyzed CÀ H functionalization methods, [221][222][223] aerobic CÀ H functionalization strategies that use molecular O 2 as a sustainable oxidant in place of metal catalysts, [224] metal-free electrochemical oxidative CÀ H trifluoroalkylations, [225][226][227] and biocatalytic methods that employ artificial enzymes for direct and selective CÀ H functionalization. [228,229] This list is not exhaustive and many new methodologies emerging from the field of organic synthesis can conceivably be applied to polymer upcycling, though the efficacy of such reactions on polymers will remain an open question until further investigations can be carried out.…”