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Strawberry is a food rich in bioactive compounds with great antioxidant potential. However, due to the high incidence of pests that affect crop cultivation, phytosanitary management still lacks control methods for agroecological cultivation. Thus, the present research aimed to evaluate the chemical composition and the potential of the essential oil of the leaves of Piper macedoi in the control of Cerosipha forbesi in laboratory and semi-field conditions. The concentration of essential oil in the leaves of P. macedoi that showed the highest mortality was 2.0 ml/L of oil, with a mortality above 91% under laboratory conditions. A mortality rate of 80% for all concentrations tested was observed after 24 h in all conditions tested. Thus, using essential oil from the leaf of P. macedoi can be a highly viable strategy in managing the aphid C. forbesi since it showed high mortality rates with small doses of oil.

Tomato is one of the most produced and consumed fruits in the world. However, it is a crop that faces several phytosanitary problems, such as fusarium wilt, caused by Fusarium oxysporum. Thus, this study aimed to evaluate citronella and melaleuca essential oils in vitro potential in the fungus F. oxysporum management. The chemical identification of the components in the essential oils was performed by gas chromatography with flame ionization and mass spectrometer detectors. The IC50 and IC90 were determined by linear regression and the percentage of inhibition of the fungus by analysis of variance. The major compounds in citronella essential oil were citronellal, Geraniol, and citronellol; in melaleuca (tea tree) oil were terpinen-4-ol and α-terpinene. Both oils promoted more significant inhibition at concentrations of 1.5 and 2.5 μL/mL, besides not presenting significant differences with commercial fungicides, confirming the high potential for using this control method in agriculture.

Two-spotted spider mite causes significant damage to various crops, often requiring synthetic acaricides for their control. However, the frequent use of these products causes several environmental problems. Thus, this work aimed to evaluate the acaricidal action, using the application by fumigation on female adults of Tetranychus urticae of essential oil from the leaves of Rosmarinus officinalis L., and its major compound, α-pinene. In addition, the essential oil was characterized by gas chromatography and mass spectrometry. α-pinene was the compound with the highest relative area in the oil (29.2%). In fumigation tests, α-pinene showed more significant toxicity than rosemary essential oil on two-spotted spider mite females with LC50 and LC90 values of 1.58 and 49.61 µL/L air, showing the impact of the chemical composition of the essential oil on the biological activity.

β-Citronellol and geraniol are bio-renewable compounds found in essential oils of various plants. Allylic oxidation of trisubstituted sterically highly encumbered carbon-carbon double bonds in their molecules with dioxygen can be efficiently catalyzed by the palladium acetate/p-benzoquinone combination under 5−10 atm of dioxygen pressure without the need for conventionally used metal co-catalysts. Both substrates gave allyl acetates in ca. 90% combined yield. The oxidation of geraniol proceeded with excellent site-selectivity involving only one of its two C C bonds. Geraniol gave both linear and branched allyl acetates in comparable yields, whereas the reaction of β-citronellol showed high regioselectivity for the corresponding branched product. Polyfunctionalized oxygenated terpenes produced from β-citronellol and geraniol are of a potential importance as ingredients for fragrance compositions.

Linalool and nerol, bio-renewable terpenic alkenyl alcohols found in many essential oils, were selectively oxidized by molecular oxygen in the presence of the chloride-free Pd(OAc) 2 / p -benzoquinone catalytic system. An efficient dioxygen-coupled catalytic turnover was achieved in the absence of auxiliary electron-transfer mediators under 5–10 atm of oxygen pressure. In both substrates, only one of two olefinic bonds was involved in the interaction with palladium, whereas the other one remained intact. Primary allylic acetates were formed as major reaction products: 8-linalyl acetate and 8-neryl acetate from linalool and nerol, respectively. In the case of linalool, the intramolecular cyclization product (known as herboxide), also resulted from the oxidation of the internal double bond, was also formed in significant amounts. All monoterpenic compounds obtained in the present work are natural products found in exotic plants or grape wines and are potentially useful as fragrance ingredients due to their pleasant scents.

α-Bisabolol, a sesquiterpene found in various essential oils, has numerous direct commercial uses in cosmetic and therapeutic formulations. In the present work, we report two novel liquid-phase processes for the catalytic oxidation of α-bisabolol with dioxygen, in which palladium salts (PdCl 2 or Pd(OAc) 2 ) are employed as sole catalysts. The addition of co-catalysts conventionally used for the re-oxidation of reduced palladium species or special ligands for their stabilization is not required. The reactions occur in non-acidic solvents, i.e., aqueous methanol or dimethylacetamide, and give exclusively the products derived from the interaction of the acyclic olefinic bond with palladium, whereas the other olefinic bond remains intact. The method allows to perform the green and simple synthesis of poly-functionalized compounds potentially useful for fine chemical industry as fragrance ingredients and synthetic intermediates, starting from a bio-renewable substrate.

A novel selective palladium catalyzed oxidation of α-bisabolol by molecular oxygen under chloride-free nonacidic conditions has been developed. α-Bisabolol is a sesquiterpenic alcohol available from essential oils of various plants. The reaction proceeds in aqueous methanol solutions over the Pd(OAc)2/Cu(OAc)2 catalytic system and gives exclusively the products resulting from the interaction of palladium with a sterically encumbered internal acyclic double bond. No concomitant oxidation of the second double bond, the endocyclic one, occurs. Novel poly-functionalized sesquiterpenoid compounds obtained at the oxidation of α-bisabolol are potentially interesting for cosmetic, fragrance and pharmaceutical applications.

The palladium/p-benzoquinone catalyzed aerobic oxidation of α-bisabolol, a bio-renewable substrate with strong therapeutic potential available from various essential oils, has been developed. The reaction gives three main products arising from the oxidation of the sterically encumbered trisubstituted double bonds of the substrate, either endocyclic or exocyclic or both. Novel poly-functionalized sesquiterpenoids obtained with high combined selectivity from the oxidation of α-bisabolol are potentially useful as components of synthetic perfumes, cosmetics and pharmaceuticals. The system promotes an efficient dioxygen-coupled catalytic turnover in the absence of auxiliary redox-active co-catalysts under superatmospheric oxygen pressure. Alternatively, the reaction can be performed at atmospheric pressure in the presence of catalytic amounts of copper acetate as an electron transfer mediator for the regeneration of BQ during the catalytic cycle.

A palladium-catalyzed, aerobic oxidation of naturally occurring allylbenzenes, i.e., eugenol, methyleugenol, safrole, and estragole, in dimethyl-acetamide/water solutions under mild conditions has been developed, in which palladium(II) chloride is used in the absence of co-catalysts or special stabilizing ligands as the sole and recyclable catalyst. Methyl ketones that are important for the flavour and pharmaceutical industries have been obtained in good to excellent yields with low catalyst loadings (1―2 mol%) and high average turnover frequencies. This simple catalytic method represents an ecologically benign and economically attractive route to industrially valuable compounds starting from renewable substrates easily available from essential oils.

Nuclear oxybromination of unprotected aromatic primary amines catalyzed by copper(II) acetate [Cu(OAc)2] under mild conditions has been developed, in which bromide ions are used as halogenating agents and dioxygen as a final oxidant. The catalyst shows not only high regioselectivity for para- or ortho-isomers but also a remarkable chemoselectivity for monobromination. Oxychlorination of aniline can also be performed under similar conditions, albeit with lower selectivities, with N-phenylacetamide being the main by-product. This simple catalytic method represents ecologically benign and economically attractive synthetic pathway to expensive low-volume aromatic haloamines.

Cobalt- and manganese-substituted ferrites were used as heterogeneous catalysts for liquid-phase aerobic oxidation of various monoterpenic alkenes . The materials were prepared by co-precipitation and characterized by Mossbauer spectroscopy, powder X-ray diffractometry, magnetization measurements, and elemental analysis. The results show that isomorphic substitution of iron in the ferrite crystalline structure occurred preferentially at octahedral positions and strongly affected its catalytic properties in the oxidation of monoterpenes . Various valuable oxygenated monoterpenic compounds were obtained with high combined selectivities (75–95%) at ca. 40% substrate conversions. Oxidations of β-pinene and 3-carene led almost exclusively to allylic mono-oxygenated derivatives, whereas limonene and α-pinene gave both epoxides and allylic products. The use of inexpensive catalyst and oxidant, solvent-free conditions, and high final product concentrations (ca. 40 wt%) are significant practical advantages of this environmentally friendly process. The catalysts undergo no metal leaching and can be easily recovered by the application of an external magnet and reused.

A simple, low cost and highly selective method for the synthesis of mono-bromophenols from phenol and electron-rich phenolic compounds has been developed. Bromide ions are used as halogenating agents, dioxygen as a final oxidant, and Cu(OAc) 2 as a catalyst.

Oxychlorination of phenol and electron-rich phenolic compounds catalyzed by CuCl 2 under mild conditions has been developed. Chloride ions are used as halogenating agents and dioxygen as a final oxidant. The catalyst shows not only high regioselectivity for para - or ortho isomers but also a remarkable chemoselectivity for monochlorination, with no products of the oxidation of phenols being formed in detectable amounts. Non-phenolic aromatics and phenols with electron withdrawing substituents undergo no transformation at all under similar conditions. A free radical mechanism is suggested, which involves one-electron oxidation of phenol by CuCl 2 to the corresponding phenoxy radical followed by a rapid reaction of the tautomeric cyclohexadienyl radical with CuCl 2 resulting in chlorinated product and CuCl. Re-oxidation of CuCl by dioxygen completes a catalytic cycle. This simple, low cost and selective method might be applied for the synthesis of chlorophenols, which are widely used in pharmaceutical, agricultural and dye industries.

Oxidation of limonene, α-pinene and β-pinene with dioxygen in acetic acid and acetonitrile solutions containing catalytic amounts of CoCl 2 has been studied. Limonene and α-pinene give both allylic oxidation and epoxidation products in a molar ratio of near 1/1, with chemoselectivities for corresponding products being higher in acetonitrile than those in acetic acid. On the other hand, oxidation of β-pinene leads essentially to allylic products, i.e. highly valuable pinocarveol, pinocarvone, myrtenol and myrtenal. In acetic acid, a combined selectivity for these products does not exceed 40% due to the concomitant substrate isomerization and acetic acid addition, while in acetonitrile, good selectivities of up to 85% at a 40–50% substrate conversion have been achieved.

Nuclear oxybromination of unprotected aromatic primary amines catalyzed by copper(II) acetate [Cu(OAc)2] under mild conditions has been developed, in which bromide ions are used as halogenating agents and dioxygen as a final oxidant. The catalyst shows not only high regioselectivity for para- or ortho-isomers but also a remarkable chemoselectivity for monobromination. Oxychlorination of aniline can also be performed under similar conditions, albeit with lower selectivities, with N-phenylacetamide being the main by-product. This simple catalytic method represents ecologically benign and economically attractive synthetic pathway to expensive low-volume aromatic haloamines.