Chloromethylation of Lignin as a Route to Functional Material with Catalytic Properties in Cross-Coupling and Click Reactions.

Invited for this issue's cover are researchers from Tallinn University of Technology (TalTech). The image depicts the lignin chemical evolution route from raw biomass through a greener chloromethylation procedure developed by the research team. It showcases the transformation into lignin-supported metal nanoparticles, serving as a catalyst for various chemical reactions in both batch and continuous flow conditions.

Chloromethylation of Lignin as a Route to Functional Material with Catalytic Properties in Cross-Coupling and Click Reactions.

We present a novel, greener chloromethylation procedure for organosolv aspen lignin under mild reaction conditions without Lewis acid as a catalyst and in acetic acid as a solvent. This synthetic protocol provides a reliable approach to chloromethylated lignin (CML) and means to obtain valuable lignin derivatives. The resulted CML was subsequently transformed into 1-methylimidazolium lignin (ImL), which effectively serves as a stabilizing agent for Pd/CuO nanoparticles (Pd/CuO-NPs).

Inhibition of glutathione S-transferases by photoactive calix[4]arene α-ketophosphonic acids.

Calix[4]arenes bearing photoactive α-ketophosphonic acid groups at the upper rim of the macrocycle were synthesized and evaluated as inhibitors of glutathione S-transferases. Irradiation at 365 nm increased the inhibition effects of some macrocyclic compounds on GSTP1-1 by more than two orders of magnitude. Calix[4]arene bis-α-ketophosphonic acids substituted at the lower rim by n-propyl or n-butyl groups showed IC values in the low micromolar range.