Reactions of Terpenes Catalyzed by Heteropoly Compounds: Valorization of Biorenewables

Hydration of Camphene over PW-SBA-15-SO3H

The hydration of camphene was carried out over SBA-15 with sulfonic acid groups and tungstophosphoric acid at 50 °C. The main product of camphene hydration was isoborneol, with camphene hydrate and borneol as byproducts. The catalytic activity increased with the amount of tungstophosforic acid (PW) immobilized on the silica support until a maximum, which was obtained with the PW4-SBA-15-SO₃H material (16.4 wt.%). When the amount of PW immobilized on SBA-15 increased (PW5-SBA-15-SO₃H, 21.2 wt.%), the catalytic activity decreased. The catalytic activity of PW4-SBA-15-SO₃H increased with the water content of the solvent, until a maximum was reached with 50% water. With higher water concentrations, a decrease in the catalytic activity was observed. The selectivity to isoborneol was 90% at 99% camphene conversion in the presence of the PW4-SBA-15-SO₃H catalyst. The catalytic stability of the PW4-SBA-15-SO₃H material during camphene hydration was studied by performing consecutive batch runs with the same catalyst sample. After the third run, a trend towards stabilized catalytic activity was observed. A kinetic model is also proposed.

Synthesis, characterization and optimization of heterogeneous catalytic cyclohexene oxidation by tungstophospho(aqua)ruthenate via the fractional factorial design methodology

Keggin-type tungstophospho(aqua)ruthenate (PRuW) was synthesized and supported on acid activated montmorillonite under mild conditions.

Self-assembly generation, structural features, and oxidation catalytic properties of new aqua-soluble copper(ii)-aminoalcohol derivatives

Multidentate aminoalcohols were applied as unexplored building blocks to generate two novel Cu(ii) coordination compounds that act as efficient catalysts for the mild and acid-promoter-free oxidation of C₅–C₈ cycloalkanes.

Heteropoly acid catalysts for the synthesis of fragrance compounds from bio-renewables: acetylation of nopol and terpenic alcohols

Commercially important esters are obtained from biomass-based alcoholsviagreen solvent-free catalytic processes under ambient conditions using a simple heterogeneous catalyst.