Conversion of lignin feedstocks into aromatic chemicals is a highly desirable target for biorefineries, and their depolymerization often requires high temperatures and harsh conditions. In this work, a process optimization involving several factors, including catalyst dosage, reaction temperature, reaction time, oxygen pressure and solvent effect, towards vanillin production from the oxidation of lignin-based vanillyl alcohol in a base-free solvent over a LaFeO₃ perovskite was proposed. The results pronounced that the LaFeO₃ perovskite exhibited excellent catalytic performance for affording a 100.0% conversion rate of vanillyl alcohol and 33.0% vanillin yield with the addition of 0.1 g LaFeO₃ dosage at 180 °C for 2 h under 1.0 MPa O₂ supply in ethyl acetate solvent. Furthermore, the presence of oxygen vacancies (Fe³⁺–□–Fe²⁺) in the LaFeO₃ perovskite contributed to combining with molecular oxygen to generate the active species [Fe³⁺O₂ ⁻], which played a key role in the oxidation of vanillyl alcohol and dominated the formation pathway of vanillin. On the other hand, reusability tests manifested that the performance of LaFeO₃ decreased gradually with the increase of consecutive runs and was strongly negatively related to the amount of carbon deposits, as carbon deposits would prevent vanillyl alcohol from being accessible to active sites. Nevertheless, the performance of the spent LaFeO₃ catalyst could be easily regenerated by a simple calcination approach. Overall, this work provides the possibility of a scalable strategy for constructing LaFeO₃-based perovskites as efficient and reusable catalysts for vanillin production from biorefinery lignin.

Background: The development of new antifungal agents has always been a hot research topic in pesticide development. In this study, a series of derivatives of natural compound β-pinene were prepared, and the antifungal activities of these derivatives were evaluated. The purpose of this work is to develop some novel molecules as promising new fungicides. Methods: Through a variety of chemical reactions, β-pinene was transformed into a series of β-pinene-based derivatives containing amide moieties and acylthiourea moieties. The antifungal activities of these derivatives against five plant pathogens including Colletotrichum gloeosporioides, Fusarium proliferatum, Alternaria kikuchiana, Phomopsis sp. and Phytophthora capsici were tested; preliminary structure–activity relationship was discussed. Results: Some derivatives exhibited moderate or significant antifungal activity due to the fusion of the amide moiety or the acylthiourea moiety with the pinane skeleton. The structure–activity relationship analysis showed that the fluorine atom and the strong electron withdrawing nitro group, or trifluoromethyl group on the benzene ring of the derivatives had a significant effect on the improvement of the antifungal activity against Colletotrichum gloeosporioides, Fusarium proliferatum, Alternaria kikuchiana and Phomopsis sp. Meanwhile, the introduction of an ethyl group at the meta-position on the benzene ring of the derivatives could improve the antifungal activity against Phytophthora capsici. Compounds 4e, 4h, 4q, 4r exhibited broad-spectrum antifungal activity against the tested strains. Compound 4o had significant antifungal activity against Phytophthora capsici (IC₅₀ = 0.18 μmol/L). These derivatives were expected to be used as precursor molecules for novel pesticide development in further research.