Acylation of cellulose with N,N′-carbonyldiimidazole-activated acids in the novel solvent dimethyl sulfoxide/tetrabutylammomnium fluoride

Abstract

Carboxylic acids were efficiently activated with N,N′- carbonyldiimidazole (CDI) and applied for the acylation of cellulose under homogeneous conditions using dimethyl sulfoxide (DMSO)/tetrabutylammonium fluoride trihydrate (TBAF) as solvent. The simple and elegant method is a very mild and easily applicable tool for the synthesis of pure aliphatic, alicyclic, bulky, and unsaturated cellulose esters with degrees of substitution of up to 1.9. Products are soluble in organic solvents, e.g., DMSO or N,N-dimethylformamide (DMF). The cellulose esters were characterized by elemental analysis, FF-IR, 1H nnd 13C NMR spectroscopy and show no impurities or substructures resulting from side reactions.