Halloysite functionalized with dendritic moiety containing vitamin B1 hydrochloride as a bio-based catalyst for the synthesis of 5-hydroxymthylfurfural.

Using halloysite clay and vitamin B1 hydrochloride, a novel acidic halloysite-dendrimer catalytic composite has been developed for conversion of fructose to 5-hydroxymthylfurfural. To grow the dendritic moiety on halloysite, it was first functionalized and then reacted with melamine, epichlorohydrin and vitamin B1 hydrochloride respectively. Then, the resulting composite was treated with ZnCl to furnish Lewis acid sites.

Clay-supported bio-based Lewis acid ionic liquid as a potent catalyst for the dehydration of fructose to 5-hydroxymthylfurfural.

Caffeine and halloysite nanoclay mineral that are bio-based compounds were utilized to synthesize a novel Lewis acid heterogeneous catalyst. To this aim, halloysite was functionalized with 2,4,6-trichloro-1,3,5-triazine and reacted with caffeine, which was then converted to ionic liquid via a reaction with ZnCl. The catalyst was applied for promoting the dehydration of fructose to 5-hydroxymethylfurfural.

3D-Printed Cyclodextrin Polymer Encapsulated Wells-Dawson: A Novel Catalyst for Knoevenagel Condensation Reactions.

In the pursuit of enhancing the catalytic potential of the Wells-Dawson (WD) polyoxometalate (POM) while addressing its solubility challenges, this study focuses on devising a sustainable catalyst that operates effectively in aqueous environments. Leveraging cyclodextrin (CD) polymer chemistry in conjunction with 3D printing technology, a CD nanosponge, recognized for its interaction with POMs and molecular shuttle attributes, is synthesized as a scaffold for WD immobilization. Through integration into a 3D-printed monolith framework, the supported WD species becomes embedded within the catalyst structure, facilitating its application.

Tuning the acidity of halloysite by polyionic liquid to develop an efficient catalyst for the conversion of fructose to 5-hydroxymethylfurfural.

In an attempt to prepare a low-cost and efficient acidic heterogeneous catalyst for the conversion of fructose to 5-hydroxymethylfurfural under mild reaction conditions, the acidity of halloysite was improved by covalent grafting of an acidic polyionic liquid. More precisely, halloysite was first vinyl functionalized and then polymerized with vinyl imidazole and 2-acrylamido-2-methylpropanesulfonic acid. The tangling imidazole rings were further converted to acidic ionic liquids by treating them with chlorosulfuric acid.