Alternative bisphenols, synthesized from lignin-derivable 4-n-propylguaiacol, show promising technical, sustainable and environmental advantages for various polymer applications.

Innovative catalyst design holds the key to fundamental advances in the transformation of cellulose to chemicals and transportation fuels, both of which are vital to meet the challenge of increasing energy costs and the finite nature of fossil fuel reserves. Here we report on the functionalization, characterization and successful application of sulfonated hyperbranched poly(arylene oxindole)s for the direct catalytic conversion of cellulose to levulinic acid. The use of water-soluble hyperbranched polymers in combination with ultrafiltration is conceptually novel and opens new horizons in the aqueous-phase processing of cellulose substrates with various degrees of crystallinity. Compared to most conventional types of acid catalysts, these highly acidic polymers demonstrate superior catalytic performance in terms of both activity and selectivity. Additionally, this molecular approach can be successfully transferred to the acid-catalyzed degradation of other abundant biomass resources, including starch, inulin and xylan.

An unprecedented approach that enables the direct and selective preparation of 1,5-disubstituted 1,2,3-triazoles from abundantly available building blocks such as primary amines, enolizable ketones and 4-nitrophenyl azide as a renewable source of dinitrogen via an organocascade process has been developed. Furthermore, this efficient methodology also enables the synthesis of fully functionalized and fused N-substituted heterocycles.

A metal-free three-component reaction to synthesize 1,4,5-trisubstituted 1,2,3-triazoles from readily available building blocks, such as aldehydes, nitroalkanes, and organic azides, is described. The process is enabled by an organocatalyzed Knoevenagel condensation of the formyl group with the nitro compound, which is followed by the 1,3-dipolar cycloaddition of the azide to the activated alkene. The reaction features an excellent substrate scope, and the products are obtained with high yield and regioselectivity. This method can be utilized for the synthesis of fused triazole heterocycles and materials with several triazole moieties.

Acid-catalyzed condensation of levulinic acid and phenol into high yields of diphenolic acid (>50%) is possible with a combination of sulfonated hyperbranched polymers and thiol promotors, either added as a physical mixture or bound to the polymer by ion-pairing.