Sustainable Functionalization of 2,3-Dialdehyde Cellulose via the Passerini Three-Component Reaction

Cellulose-based materials have gained more and more interest due to the increasing dependency of mankind on petroleum-based resources, especially during the last few decades. In this work, we report a mild and efficient method to modify 2,3-dialdehyde cellulose (DAC) via the Passerini three-component reaction (P-3CR) in an aqueous medium. Microcrystalline cellulose (MCC) was first oxidized to DAC and further reacted with different renewable carboxylic acids and commercially available isocyanides to obtain molecularly diverse modifications of cellulose with a degree of substitution (DS) ranging from 0.62 to 0.94. Confirmation of the structure of the obtained product was achieved via IR as well as H-1 and C-13 NMR. Differential scanning calorimetry (DSC) revealed glass transition temperatures (T-g) between 121 and 166 degrees C, depending on the chosen components for the P-3CR. Thus, we show a novel way to homogeneously modify DAC, which was so far mostly achieved by imine formation.