A tunable process: catalytic transformation of renewable furfural with aliphatic alcohols in the presence of molecular oxygen

Abstract

The tunable transformation of renewable furfural with aliphatic alcohols in the presence of O2 is developed. Based on a nano Au catalyst and potassium carbonate, a 91.8% yield of methyl 2-furoate with 98.7% selectivity is obtained via the oxidative esterification in a furfural-methanol-O2 system; while a 91.4% yield of 3-(furan-2-yl-)-2-methylacrylaldehyde with 97.2% selectivity is attained via the oxidative condensation in a furfural-n-propanol-O2 system.

Biomass Derived Chemicals: Furfural Oxidative Esterification to Methyl-2-furoate over Gold Catalysts

“…The efficient condensation of furfural with n-propanol to prepare a furfural-containing long chain aldehyde has also been reported [25]. In particular, very high yield of methyl-2-furoate and selectivity were obtained by oxidative esterification in a furfural-methanol-O 2 system in the presence of a Au (5.0 wt %) catalyst and of K 2 CO 3 .…”

“…Acetone and aldehydes can originate from the oxidation of secondary and primary alcohols in the presence of molecular oxygen [24]. Recently, in a study on the oxidative esterification of furfural and aliphatic alcohols using an Au/FH catalyst (FH refers to FexOy-hydroxyapatite) with molecular oxygen and in the presence of a potassium carbonate, a 91.8% yield of methyl-2-furoate with 98.7% selectivity were attained using methanol (140 °C for 4 h under 0.3 MPa O2), whereas 91.4% yield of 3-(furan-2-yl-)-2-methylacrylaldehyde with 92.7% selectivity were obtained using propanol [25]. It is worth noting that oxidative condensation and oxidative esterification are competitive reactions when considering a furfural-alcohol-oxygen system, as shown in Scheme 1.…”

“…Analogously, the promising results obtained in ref. [25] as for the transformation of furfural with aliphatic alcohols in the presence of molecular oxygen (and of a base) were ascribed to the small average of the supported gold nanoparticles.…”

“…Up to now, several examples dealing with the oxidation of 2-FA in the presence of heterogeneous catalysts have been reported [23][24][25][27][28][29]. These papers mainly deal with the use of gold supported catalysts [25,[27][28][29] demonstrating the current efforts to modify furfural-based derivatives by gold catalysis, due to the fact that such supported metal systems are mainly used as suitable catalysts for selective oxidation.…”

“…These papers mainly deal with the use of gold supported catalysts [25,[27][28][29] demonstrating the current efforts to modify furfural-based derivatives by gold catalysis, due to the fact that such supported metal systems are mainly used as suitable catalysts for selective oxidation. Indeed, gold currently is a hot spot in catalysis research [30,31].…”