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BACKGROUND: The olive fruit fly (OFF), Bactrocera oleae (Rossi), is the main insect pest of olive trees worldwide. Legislation limits to the use of some synthetic larvicidal insecticides is leading to the development of new control options for preventive control of adult flies. In the present study, the biological activity of four short‐chain aliphatic aldehydes, namely hexanal, (E)‐2‐hexenal, heptanal and (E)‐2‐heptenal, previously reported as repellents to the OFF adults was investigated. RESULTS: Electroantennography (EAG) recordings showed that antennae of OFF males and females are able to perceive the test compounds in a wide range of doses. In field trapping experiments, reservoir‐type polypropylene (PP) membrane dispensers loaded with individual compounds did not elicit a significant attraction of OFF males and females. On the contrary, a significant reduction of male catches was noticed when sex pheromone dispensers and PP membrane dispensers, loaded with one of the test compounds, were applied on the same white sticky traps ≈20 cm apart. Likewise, male and female catches in yellow sticky traps baited with ammonium carbonate (AC) dispensers as food attractant were significantly reduced by the presence of PP membrane dispensers of individual aliphatic aldehydes on the same traps. In small plots control trials, solid formulations of the four aldehydes into a bentonite clay support induced a significant reduction of the OFF active infestation mainly when C6 and C7 aldehyde‐activated bentonites were used. CONCLUSION: Short‐chain aliphatic aldehydes showed inhibitory effects on sex pheromone and food attractant‐mediated attraction of OFF. Results of field trials suggest potential of short‐chain aliphatic aldehydes to develop new semiochemical‐based OFF control options. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

A set of organic/inorganic layered materials was obtained by functionalizing a montmorillonite-containing bentonite natural clay with linear aliphatic C6 or C7 aldehydes through a cost-effective and technologically simple incipient-wetness deposition method. The solids were investigated by means of a multi-technique approach (X-ray powder diffraction, XRPD, scanning electron microscopy, SEM, Fourier-transform infrared spectroscopy, FT-IR, thermogravimetric analysis, TGA, elemental analysis and solid-state nuclear magnetic resonance, ssNMR) to clarify the nature of the deposited organic species and the mode of interaction between the aldehyde and the clay. Since both natural clays and short-chain linear aldehydes find application as alternative strategies in the control of the olive fruit fly, Bactrocera oleae, the hybrid layered materials were tested under real-life conditions and their insect-inhibiting capability was evaluated in open-field trials on olive tree orchards in Tuscany, Central Italy. Specific tests were conducted to evaluate the resistance of the solids to weathering and their capability to provide a constant and long-lasting release of the bioactive ingredient. Aldehyde-containing bentonite clays have shown promising performance in controlling B. oleae infestation (with up to 86–95% reduction of affected olive fruits) in open-field trials across two years in two locations with different pedological and meteo-climatic characteristics. [ABSTRACT FROM AUTHOR]

The cytotoxicity of ionic liquids (ILs) has been receiving attention in the context of the biological and environmental impact of their vast field of applications. It has been ascertained that the cell membrane is the main target of ILs when they interact with microorganisms, cells and bacteria; nevertheless, studies at the micro- and nano-scale aiming at better understanding of the fundamental mechanisms of toxicity of ILs are lacking. In this work, we used atomic force microscopy (AFM) to investigate the impact of room-temperature ILs on the mechanical, morphological and electrostatic properties of solid-supported DOPC phospholipid bilayers, taken as models of biomembranes. In particular, we have characterized the concentration-dependent and time-dependent evolution of the morphological, structural and mechanical properties of DOPC lipid membranes in the presence of imidazolium-based ILs with different alkyl chain lengths and hydrophilic/hydrophobic characteristics. The majority of ILs investigated were found to possess the ability of restructuring the lipid bilayer, through the formation of new IL/lipid complexes, showing distinctive morphological features (increase of area and roughness). The nanomechanical analysis of the lipid membrane exposed to ILs revealed a progressive, concentration-dependent perturbation of the structural ordering and rigidity of the membrane, evidenced by a decrease in the breakthrough force, Young's modulus and area stretching modulus. AFM detected a modification of the electrostatic double-layer at the membrane surface, in terms of a reduction of the original negative surface charge density, suggesting a progressive stratification of cations on the exposed leaflet of the lipid membrane. Our findings may be helpful in designing novel ILs with tailored interaction with biological membranes. [ABSTRACT FROM AUTHOR]

Simple ammonium ferrates are competent catalysts for the CO2 coupling with aziridines to yield 5‐substituted 1,3‐oxazolidin‐2‐ones. Good yields with remarkable selectivity are obtained under mild reaction conditions, room temperature, and atmospheric CO2 pressure, especially for non‐hindered N‐alkyl, N‐benzyl and N‐allyl aziridines, without the need of any co‐catalyst. To shed light on the reaction mechanism, an extensive set of theoretical calculations has been carried out. A viable reaction mechanism involving just one ferrate molecule and where the rate determining step is the 1,3‐oxazolidin‐2‐one ring closure has been found, and the corresponding barrier is compatible with the experimental conditions tested in this study. [ABSTRACT FROM AUTHOR]

Wehave recently shown that simple ammonium ferrates are competent catalyst for the cycloaddition reaction of CO2 to epoxides under moderate reaction conditions (T = 100°C, P(CO2) = 0.8 MPa). We report here that ammonium zincates of general formulae [TBA]2 [ZnX4] (TBA = tetrabutylammonium), simply obtained by treating an ethanolic solution of an appropriate zinc(II) salt with two equivalents of tetrabutylammonium halides, outperform ammonium ferrates in the synthesis of cyclic carbonates under milder reaction conditions (room temperature and atmospheric CO2 pressure). Using [TBA]2[ZnBr4] complex as homogeneous catalyst at 100°C and P(CO2) = 0.8 MPa a 52% conversion of styrene oxide with complete selectivity in styrene carbonate in just 15 min was observed, corresponding to a Turnover frequency (TOF) of 416 h-1. The same catalyst proved to be very active even at room temperature and atmospheric or very moderate CO2 pressures (0.2 MPa), with a quite broad range of substrates, especially in the case of terminal epoxides, with high selectivity towards cyclic carbonate products. The difference in reactivity of terminal and internal epoxides could be exploited using 4-vinylcyclohexene dioxide, where the endocyclic epoxide remained untouched when reacted at room temperature and the formation of the di-carbonate product was observed only at harsher conditions. A multigram scale conversion of propylene oxide was achieved (46 mmol) and the catalyst also proved to be recyclable (3 cycles) by distillation of the product and subsequent addition of fresh reagent, maintaining high conversion values and complete selectivity for propylene carbonate. This simple zinc-based catalytic system, which outperform the recently reported iron-based one by working at much milder conditions, could represent a valuable prospect in both laboratory and industrial scale, combining an inherent cheapness and synthetic easiness that should be deeply considered when the goal is to give value to a waste product as CO2. [ABSTRACT FROM AUTHOR]

The development of alternative benign reaction conditions to perform multicomponent reactions is an interesting and desirable strategy to increase the sustainability of organic synthesis. In this paper, we report a new version of A3‐coupling MCR for the preparation of differently substituted propargylamines starting from aldehydes, alkynes and amines in an acidic DES as reaction media, under dielectric heating, and in the presence of a tetraaza‐macrocyclic silver complex as catalyst. The reaction scope is broad in terms of aldehyde partners. Electron‐rich phenylacetylenes are the more reactive alkynes partners, whereas the nature of the amine is the more serious limitation as only secondary cyclic amines are tolerated. [ABSTRACT FROM AUTHOR]

A reproducible synthesis of a competent epoxidation catalyst, [Ru(super VI)(TPP)(O)2] (TPP = tetraphenylporphyrin dianion) starting from [Ru(super II)(TPP)(CO)L] (L = none or CH3OH), is described. The molecular structure of the complex is determined by using ab initio X-ray power diffraction (XRPD) methods, and its solution behavior is investigated by NMR techniques.

The role of calix(4)arene as a supporting ligand compared to cyclopentadienyl and phenoxo anion is emphasized through the micratory insertion reaction of carbon monoxide and isocyanides, in the Zr-C bond. A kinetically and structurally defined stewise insertion process is reported. The reactions occur via metal-assisted C-C bond formation, resulting in a variety of carbon-metal-bonded fragmenets. Extended Huckel calculations were also performed.

The full synthesis and chemical behaviour of the Zr-C bond functionalities bonded to the Osub4 skeleton is reported. The approach is based on the synthesis and organometallic functionalization of (calix(4)-(OMe)(O)sub3ZrC1)sub2 and (calix(4)-(OMe)sub2(O)sub2ZrC1sub2), giving rise to two classes of derivatives linked by the based-induced demethylation of a methoxy group. The main differences between the (Osub4ZR)super2+, (Osub4Zr)+ and (Cpsub2Zr)super2 fragements are emphasized.