Alkanes from Bioderived Furans by using Metal Triflates and Palladium‐Catalyzed Hydrodeoxygenation of Cyclic Ethers

Abstract

Using a metal triflate and Pd/C as catalysts, alkanes were prepared from bioderived furans in a one-pot hydrodeoxygenation (HDO) process. During the reaction, the metal triflate plays a crucial role in the ring-opening HDO of furan compounds. The entire reaction process has goes through two major phases: at low temperatures, saturation of the exocyclic double bond and furan ring are catalyzed by Pd/C; at high temperatures, the HDO of saturated furan compounds is catalyzed by the metal triflate. The reaction mechanism was verified by analyzing the changes of the intermediates during the reaction. In addition, different metal triflates, solvents, and catalyst recycling were also investigated.

Transition metal triflate catalyzed conversion of alcohols, ethers and esters to olefins

“…The experiments were conducted under solvent-free reaction conditions to exclude possible solvent-effects, as, for example, coordinating solvents have been shown to reduce the dehydration activity of Hf(OTf) 4 under hydrodeoxygenation conditions. 13,15 To rationalize the results, the octene yield and conversion were plotted as a function of the oxophilicity and Lewis acidity of the used metal cations, respectively (Fig. 1).…”

“…The replacement of the triate anion with chloride resulted in a signicantly reduced yield and conversion (Table 1, entries [14][15][16][17]. The better reactivity with triates can be explained by the weak electron donor and strong electron acceptor nature of this anion, which increases the Lewis acidity of the central metal atom.…”

Production of Jet Fuel‐Range Hydrocarbons from Hydrodeoxygenation of Lignin over Super Lewis Acid Combined with Metal Catalysts

“…Unlike Hf(OTf) 4 , Al(OTf) 3 , or In(OTf) 3 , the addition of Ni(OTf) 2 showed minimal improvement in guaiacol HDO conversion, with half of the products being oxy‐compounds. The differences in the catalytic behaviors of the tested metal triflates may lie in the differences of the effective charge density of their metal ions . In general, the Lewis acidity of metal triflates increased with the effective charge density of their central metal cations.…”

“…Guaiacol was completely converted into hydrocarbons in n ‐octane. The use of a suitable solvent such as n ‐octane was found to be better than the control reactions for the following reasons: i) Catalysts, temperature, and pressure are more stable within solvents; ii) the dissolution and transportation of H 2 are superior; iii) these solvents hold the reactant, intermediates, and products in solution . Since it is difficult and costly to remove all water from biomass feedstocks, 10 wt % of water was mixed with n ‐octane as the mixed solvent, whereby approximately 100 % guaiacol conversion was observed and the yield of hydrocarbons was acceptable.…”

Electrochemical Coupling of Biomass‐Derived Acids: New C8 Platforms for Renewable Polymers and Fuels

“…We therefore performed the aldol reaction in tandem with hydrogenation of the double bond to provide mainly methyl 2‐methylcyclopentyl ketone ( 6 ) alongside small amounts of the alternative cyclization product 3‐methylcycloheptanone ( 7 , Scheme 4). This product mixture could be isolated and characterized, but the best yield of hydrocarbon was obtained by introducing additional Pd/C and the hydrodeoxygenation catalyst Al(OTf) 3 19 at this point, then increasing the reaction temperature and H 2 pressure to 220 °C and 50 bar, respectively. Using this approach, the total yield of cycloalkanes 8 – 11 starting from 2 was 85 %, with the relative ratios as determined by GC–MS shown.…”