On the Reactivity of Dihydro-p -coumaryl Alcohol towards Reductive Processes Catalyzed by Raney Nickel

Autor: Gaetano Calvaruso, Marco Kennema, Roberto Rinaldi, Fabian Meemken, Jorge Augusto Burak, Matthew T. Clough
Rok vydání: 2017
Předmět:
Zdroj: ChemCatChem. 9:2627-2632
ISSN: 1867-3880
DOI: 10.1002/cctc.201601590
Popis: There are several established approaches for the reductive fractiona-tion of lignocellulose (e.g. 'catalytic upstream biorefining' or 'lignin-first' approaches) that render a lignin oil product composed primarily of dehydro-p-monolignols (e.g. 4-(3-hydroxypropyl)-2-methoxyphenol, 4-(3-hydroxypropyl)-2,6-dimethoxyphenol). Although effective catalyt-ic methods have been developed in order to perform reductive or deoxygenative processes on the lignin oil, the influence of the 3-hydroxypropyl substituent on catalyst activity has previously been overlooked. Herein, to better understand the reactivity of the depoly-merized lignin oil obtained from catalytic upstream biorefining pro-cesses, dehydro-p-coumaryl alcohol is selected as a model com-pound. Hydrogenation of this species in the presence of Raney Ni with molecular hydrogen leads to ring saturation (100% selectivity) in the absence of hydrodeoxygenation, whereas under hydrogen trans-fer conditions with 2-propanol, hydrogenation occurs (ca. 55% selec-tivity) simultaneously with hydrodeoxygenation (ca. 40% selectivity). In a broader context, this study sheds light not only on the reactivity of dehydro-p-monolignols but also on the intricacies of the CUB reaction network in which these species are revealed to be key in-termediates in the formation of less functionalized p-alkylphenols.
Databáze: OpenAIRE
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