Biomass toward fine chemical products: Oxidation of α-pinene over sieves nanostructured modified with vanadium

Catalytic Oxidation Processes for the Upgrading of Terpenes: State-of-the-Art and Future Trends

“…An increase in the strength of Brönsted acid sites was observed at higher vanadium content. The catalysts with various metal contents were tested in the oxidation of α-pinene 1 with molecular oxygen (1 bar) in acetonitrile ( Table 24) Molecular sieves based on a MCM-41 structure were also used to support vanadium species, using VO(SO4)•H2O as metal precursor, cetyltrimethylammonium bromide salt as template and tetraethoxysilane as silica source [83]. UV-Vis-DR and FT-IR Raman studies proved the presence of two types of V +  species, as well as oligonuclear nanoclusters (V δ+… O δ−… V δ+ ), which could be found either inside or also on the wall of the support.…”

“…Oxidation of α-pinene 1 over V-M(x) catalysts. Influence of the metal content a (adapted from reference[83]). ), α-pinene (0.17 mmol), H2O2 (1.79 mmol), CH3CN, 70 °C, 7 h. b Ratio of converted species to initial concentration.…”

“…As already reported in the literature, the isomerization of α-pinene oxide 5 leading to campholenic acid is favored on Lewis acid sites, while trans-carveol formed over Brönsted sites. Molecular sieves based on a MCM-41 structure were also used to support vanadium species, using VO(SO 4 )•H 2 O as metal precursor, cetyltrimethylammonium bromide salt as template and tetraethoxysilane as silica source [83]. UV-Vis-DR and FT-IR Raman studies proved the presence of two types of V δ+ species, as well as oligonuclear nanoclusters (V δ+ .…”

Kinetic study of α-pinene allylic oxidation over FePcCl16-NH2-SiO2 catalyst

“…Verbenone has been obtained using homogeneous and heterogeneous catalysts with moderate yields (Table 1) [14,15]; however, the requirement of expensive and toxic solvents [16][17][18][19], difficulty in catalyst recovery and product purification [20], inert atmosphere or large amount of catalyst and time, limit the application in some of those systems. Furthermore, in some cases reports do not include catalytic stability [21].…”

Thermodynamic Analysis of α‐Pinene and Limonene Allylic Oxidation over a FePcCl16‐NH2‐SiO2 Catalyst

“…Orange oil extracted from orange peels mainly contains limonene (91-96 wt %) [6]. The commercial value of orange and turpentine oils can be increased through chemical transformations of a-pinene and limonene into epoxides, alcohols, aldehydes, ketones, and polymers [7][8][9][10], used in the production of specialty chemicals [11]. There is limited information in the literature regarding thermodynamic properties of the terpenes involved in a-pinene and limonene oxidation.…”