One-Pot Synthesis and Electrospinning of Cellulose Derivatives Bearing Pseudo-Peptide Pendants via Ugi Four−Component Reaction for Functional Nanofiber Fabrication

Abstract

The one-pot synthesis and electrospinning of cellulose derivatives bearing pseudo-peptide pendants, which are expected to serve as novel chiral recognition materials, are reported. Ugi four-component reactions (U-4CRs) involving carboxymethyl cellulose (CMC), formaldehyde, a glycine-based isocyanide (ethyl isocyanoacetate), and six different amino acid methyl esters as the carboxylic acid, aldehyde, isocyanide, and amine components, respectively, were employed to introduce pseudo-peptide pendants onto the cellulose backbone. The reactions proceeded successfully under weakly acidic conditions (pH 4), yielding derivatives with degrees of substitution (DSs) of 0.37−0.44, whereas reactions at pH 1−3 and 5 were hindered by competing side reactions. The derivatives were characterized by FTIR, NMR, size-exclusion chromatography, and elemental analysis. Furthermore, they were successfully electrospun using poly(ethylene oxide) as a carrier polymer, producing uniform and continuous nanofibers. These results demonstrate the feasibility of combining U−4CR with electrospinning to fabricate functional cellulose-based nanofibrous materials for potential chiral recognition applications.