Recent advances in synthesis strategies for biomass-derived high-energy-density jet fuels

High-energy-density jet fuels enable volume/weight-limited aircraft to exhibit a higher speed, payload, and flying range. Lignocellulosic biomass, with renewability and sustainability, has gained prominence in highenergy-density jet fuel production. This review systematically summarizes the current progress in the regioselective synthesis of high-energy-density jet fuels through different C -C coupling strategies, such as aldol condensation, hydroalkylation/alkylation, the Diels -Alder reaction, oligomerization, reductive coupling, Robinson annulation, the Guerbet reaction, Michael addition, and cyclopropanation. First, the structure-property relationship of fuel molecules was analyzed. The components of high-energy-density jet fuels are then classified into linear/branched alkanes, mono/bi-cyclo-alkanes, polycyclic cyclo-alkanes, spiro/bridge cyclo-alkanes, branched bi/polycyclic cyclo-alkanes, and mixed cyclo-alkanes, based on their molecular characteristics. The synthesis of each fuel type is summarized based on the C -C coupling strategies and feedstocks used. Finally, the challenges of current high-energy-density jet-fuel synthetic strategies are described, along with the scope for future research. This review can guide the development of improved methods and schemes for the synthesis and upgrading of high-energy-density jet fuels.