Synthesis of renewable C–C cyclic oxygenated compounds dedicated for high-density biofuels from biomass-derived cyclopentanone

Abstract

Catalytic upgrading of biomass-derived molecules into high density bio-fuels via C–C coupling reactions is a very attractive topic. Herein, magnesium hydroxide, magnesium carbonate and basic magnesium carbonate, as the typical representative of metal hydroxides, salts of strong bases and weak acids, and basic carbonates, were prepared and then applied for self-condensation of cyclopentanone. Interestingly, basic magnesium carbonate (i.e., 4MgCO₃·Mg(OH)₂·4H₂O) exhibited the highest catalytic performance, giving 76.7% yield of 2-cyclopentylidenecyclopentanone (BCPO) at 180 °C after 4 h. The superior catalytic performance of 4MgCO₃·Mg(OH)₂·4H₂O was attributed to it having an appropriate number of base sites and good accessibility to active sites, as evidenced from multiple characterization technologies. Moreover, the activation energy (92.93 kJ mol⁻¹) of self-condensation of cyclopentanone over 4MgCO₃·Mg(OH)₂·4H₂O is comparable with the previously reported values, further supporting the remarkable activity of 4MgCO₃·Mg(OH)₂·4H₂O. This work illustrates the conspicuous opportunities for basic carbonates in self-condensation of cyclopentanone, indicating their promising potential for important catalytic applications in base-catalyzed C–C coupling reactions.