Production of Low‐Freezing‐Point Highly Branched Alkanes through Michael Addition

Abstract A new approach for the production of low‐freezing‐point, high‐quality fuels from lignocellulose‐derived molecules was developed with Michael addition as the key step. Among the investigated catalysts, CoCl 2 ⋅6 H 2 O was found most active for the Michael addition of 2,4‐pentanedione with FA (single aldol adduct of furfural and acetone, 4‐(2‐furanyl)‐3‐butene‐2‐one). Over CoCl 2 ⋅6 H 2 O, a high carbon yield of C 13 oxygenates (about 75 %) can be achieved under mild conditions (353 K, 20 h). After hydrodeoxygenation, low‐freezing‐point (<223 K) branched alkanes with 13 carbons within jet fuel ranges were obtained over a Pd/NbOPO 4 catalyst. Furthermore, C 18,23 fuel precursors could be easily synthesized through Michael addition of 2,4‐pentanedione with DFA (double‐condensation product of furfural and acetone) under mild conditions and the molar ratio of C 18 /C 23 is dependent on the reaction conditions of Michael addition. After hydrodeoxygenation, high density (0.8415 g mL −1 ) and low‐freezing‐point (<223 K) branched alkanes with 18, 23 carbons within lubricant range were also obtained over a Pd/NbOPO 4 catalyst. These highly branched alkanes can be directly used as transportation fuels or additives. This work opens a new strategy for the synthesis of highly branched alkanes with low freezing point from renewable biomass.