Origins of Catalyst Inhibition in the Manganese‐Catalysed Oxidation of Lignin Model Compounds with H₂O₂

Abstract

The upgrading of complex bio‐renewable feedstock, such as lignocellulose, through depolymerisation benefits from the selective reactions at key functional groups. Applying homogeneous catalysts developed for selective organic oxidative transformations to complex feedstock such as lignin is challenged by the presence of interfering components. The selection of appropriate model compounds is essential in applying new catalytic systems and identifying such interferences. Here, it was shown by using as an example the oxidation of a model substrate containing a β‐O‐4 linkage with H2O2 and an in situ‐prepared manganese‐based catalyst, capable of efficient oxidation of benzylic alcohols, that interference from compounds liberated during the reaction can prevent its application to lignocellulose depolymerisation.

Light-Induced Reactivity Switch at O2–Activating Bioinspired Copper(I) Complexes

“…We envision that the present results, beyond improving fundamental knowledge of Cu-dioxygen reactivity, will find some crucial application in the field of copper catalysis. In particular, aryl ether linkages are important targets found in numerous biomolecules as lignin . Future work in our laboratory will be devoted to the transfer of this reactivity toward external substrates.…”

“…In particular, aryl ether linkages are important targets found in numerous biomolecules as lignin. 57 Future work in our laboratory will be devoted to the transfer of this reactivity toward external substrates.…”

Transition-Metal-Catalyzed C–H Bond Activation for the Formation of C–C Bonds in Complex Molecules

“…Furthermore, as the functional group density and diversity increase with increasing molecular complexity, the prospect of catalyst intolerance of a specific functional group within the target molecule may limit applicability . If the selected substrate for functionalization possesses units with strongly coordinating groups these can compete for catalyst binding, and either partially or completely inhibit the desired reactivity by competitive catalyst coordination or complete sequestration. − Robustness screening of a wide selection of additive reagents added into optimized reaction procedures using simple substrates has allowed for elucidation of inhibitory and intolerable functional groups within established procedures and thus has served as a guide before the application to high-value complex molecules is attempted …”