“Sustainable Esterification: Mechanochemical Benzoylation as a Solvent-Free Alternative for Carbohydrate Protection”

Mechanochemical methods provide a solvent-minimised, energy-efficient route for performing common transformations in carbohydrate chemistry. This paper reports optimised protocols for the mechanochemical protection of monosaccharides and disaccharides to deliver O -benzoyl-protected sugars. We compare yields, selectivity, and reaction times with classical solution-phase methods and provide mechanistic insight from control experiments and spectroscopic characterisation (NMR and IR). The mechanochemical approach exhibits comparable selectivity, shorter reaction times, and improved sustainability metrics, such as the E-factor and solvent use, while also providing a unique response to different sugars under the same reaction conditions. Importantly, direct benzoylation with p -nitrobenzoic acid and p -chlorobenzoic acid produced the desired benzoyl derivatives in high yields, indicating a cost-effective process.