With the increasing concerns about pollution and reduction of energy demands, the use of solar energy to drive chemical transformations is becoming increasingly attractive. Within the context of sustainability, sunlight‐driven organic transformation of biomass feedstock, such as free carbohydrates, to obtain high added‐value products is an important topic in which the recent progress should contribute to the development of solar biorefineries. Among the variety of photocatalysts, gold nanoparticles (NPs) loaded onto large bandgap semiconductors represent the state of the art. Such catalysts are known to accelerate the targeted reaction upon plasmonic excitation. In addition, as noble metal NPs, they also hold an additional role related to surface catalysis, which has been exploited for aerobic oxidation of free sugars. Nevertheless, the respective contribution of each role during transformation is not well established. Herein, the enhancement of the O2‐mediated oxidation of free sugars using Au NPs on CeO2 under standard air mass 1.5G illumination conditions is reported. The results highlight that the plasmonic contribution of Au NPs is totally annihilated and this enhancement stems solely from a thermal activation process induced by NIR radiation from standard white‐light conditions.

Due to their easy conversion into high-added value products, sugar lactones and their derivatives are very attractive biobased platform molecules. Yet, conventional transformation of free sugars into such activated compounds is not so handy: a multistep procedure requiring protection/oxidation/lactonizationesterification/deprotection is often necessary. We report herein a procedure allowing one to rapidly and efficiently form lactones/ esters directly from free sugars under mild conditions, catalyzed with a small amount (0.36 mol %) of recyclable gold nanocatalyst under oxygen atmosphere. The conditions were optimized using galactose as a model, quantitatively and selectively affording 1,4galactonolactone in 2 h at room temperature. The procedure was then successfully applied to a variety of hexoses and pentoses leading to excellent conversion (>86%). Due to the equilibrium between lactone regioisomers and ester forms, a mixture of 1,4lactone, 1,5-lactone and methyl ester can be generally obtained depending on the sugar series. A subsequent reaction of the crudes with benzylamine leads to a total conversion of lactones/esters into corresponding amides, confirming the efficiency of the procedure and paving the way to a one-pot transformation of free sugars into high added value sugar-based derivatives. Based on NMR and ESR analyses, a mechanism of the reaction involving CH 3 O • radical species seems to be taking shape.