Boosting the utilization efficiency of glucose via a favored C-C coupling reaction

The efficient utilization of renewable glucose has enormous potential to reduce the excessive dependence on fossil resources, but remains challenging owing to the inevitable formation of undesirable humins and multistep processes. Reported here is a new 2,4-pentanedione/H2O-NaCl biphasic system for the direct one-step conversion of glucose to high-quality fuel precursors with a high utilization efficiency of glucose (90%). The formation of humins is markedly restrained with an entirely new pathway, i.e. glucose directly reacts with 2,4-pentanedione to afford fuel precursors via several chemical transformations, which is totally different from the traditional glucose-to-fructose-to-HMF way. Control experiments and DFT calculations confirm that this new pathway is thermodynamically favorable compared with the traditional way. This simple system is also capable of converting starch to fuel precursors, paving a new way for the efficient valorization of glucose-based natural sugars.