High-energy-density fuels are important for volume-limited aerospace vehicles

but the increase in fuel energy density always leads to poor cryogenic performan

ce. Herein

we investigated the transposed Paternò-Büchi reaction of biomass cyclic ketone and cyclic alkene to synthesize a new kind of alkyl-substituted polycyclic hydrocarbon fuel with high energy density and good cryogenic performance. The triplet-energy-quenching results and phosphorescent emission spectra reveal the sensitization mechanism of the reaction

including photosensitizer excitation

triplettriplet energy transfer

cyclization

and relaxation

and the possible reaction path was revealed by the density functional theory (DFT) calculations. The reaction conditions of photosensitizer type and addition

molar ratio of substrates

reaction temperature

and incident light intensity were optimized

with the target product yield achieving 65.5%. Moreover

the reaction dynamics of the reaction rate versus the light intensity are established. After the hydrogenation-deoxygenation reaction

three fuels with a high density of≥0.864-0.938 g·ml

-1

and a low freezing point of 55 ℃ are obtained. This work provides a benign and effective approach to synthesize high-performance fuels.