Synergetic Bimetallic Oxidative Esterification of 5-Hydroxymethylfurfural under Mild Conditions

Abstract

5-Hydroxymethylfurfural (HMF) has become a benchmark chemical as it can be obtained by the processing of renewable biomass, making its downstream modification an important topic both in industry and academia. Finding catalytic processes for the selective derivatization of HMF is challenging due to its reactivity, hence mild conditions are needed. Here we report the selective oxidative esterification of HMF to methyl 5-(hydroxymethyl)furan-2-carboxylate and to dimethyl furan-2,5-dicarboxylate (FDCM) under mild conditions using oxygen (from air) as oxidant. A synergetic effect between the used catalysts, cobalt oxide over nitrogen-doped carbon, and ruthenium over carbon catalysts was observed by catalytic and electron paramagnetic resonance measurements. Kinetic analysis revealed a first order dependence on substrate for the cobalt catalyst and an apparent zero order for the ruthenium catalysts. The conversion rates were improved by the use of perfluoroether as solvent, proving that the oxygen diffusion is the limiting factor in the system.

Study on the Synthesis of 6-Hydroxyhexyl 5-(Hydroxymethyl) Furan-2-Carboxylate from 5-Hydroxymethylfurfural (HMF) and Alkanediols

“…Similar to the oxidation of aldehyde to acid in water in the present of heterogeneous catalysis, which forms an intermediate gem diol, a hemiacetal is formed in the oxidation reaction to the ester [15,18,19]. The formation of hemiacetal is a nucleophilic reaction, in which the formation of intermediate anions occurs in the presence of bases.…”

“…The catalytic activity of Co3O4-N@C catalysis for HMF oxidative esterification was also studied and showed positive results [14,15]. The nearest trials of HMF were limited to the coupling reaction with methanol.…”

Study of the oxidative esterification of furfural catalyzed by Au25(glutathione)18 nanocluster deposited on zirconia

“…Yield been reported mainly with Co or Pd-based catalysts often in the presence of a base [31][32][33][34][35][36][37], while only few examples exist using Au. For instance AuPd/Fe 3 O 4 associated to K 2 CO 3 has been recently proposed.…”

Prozesstechnik: Ein grüner Bruder für PET

“…Ein Batchprozess, also ein diskontinuierlich arbeitendes Verfahren, verestert HMF quantitativ und selektiv oxidativ zu FDCM. 13…”