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Alien species must adapt to new biogeographical regions to acclimatise and survive. We consider a species to have become invasive if it establishes negative interactions after acclimatisation. Xylella fastidiosa Wells, Raju et al., 1986 (XF) represents Italy’s and Europe’s most recent biological invasion. In Apulia (southern Italy), the XF-encountered Philaenus spumarius L. 1758 (Spittlebugs, Hemiptera: Auchenorrhyncha) can acquire and transmit the bacterium to Olea europaea L., 1753. The management of XF invasion involves various transmission control means, including inundative biological control using Zelus renardii (ZR) Kolenati, 1856 (Hemiptera: Reduviidae). ZR is an alien stenophagous predator of Xylella vectors, recently entered from the Nearctic and acclimated in Europe. Zelus spp. can secrete semiochemicals during interactions with conspecifics and prey, including volatile organic compounds (VOCs) that elicit conspecific defence behavioural responses. Our study describes ZR Brindley’s glands, present in males and females of ZR, which can produce semiochemicals, eliciting conspecific behavioural responses. We scrutinised ZR secretion alone or interacting with P. spumarius. The ZR volatilome includes 2-methyl-propanoic acid, 2-methyl-butanoic acid, and 3-methyl-1-butanol, which are consistent for Z. renardii alone. Olfactometric tests show that these three VOCs, individually tested, generate an avoidance (alarm) response in Z. renardii. 3-Methyl-1-butanol elicited the highest significant repellence, followed by 2-methyl-butanoic and 2-methyl-propanoic acids. The concentrations of the VOCs of ZR decrease during the interaction with P. spumarius. We discuss the potential effects of VOC secretions on the interaction of Z. renardii with P. spumarius.

The N-tert-butanesulfinylimine group behaves as a suitable electron-withdrawing group in 1-azadienes, allowing the diastereoselective synthesis of densely substituted pyrrolidines by 1,3-dipolar cycloadditions (1,3-DCs) with azomethylene ylides. The use of Ag2CO3 as catalyst has allowed one to obtain a wide variety of proline derivatives with high regio- and diastereoselectivities. Subsequent efficient transformations provide valuable proline derivatives, some of which can be used as organocatalysts. The influence of the N-tert-butanesulfinyl group on the diastereoselectivity was studied by computational methods.

Enantioconvergent catalysis has expanded asymmetric synthesis to new methodologies able to convert racemic compounds into a single enantiomer. This review covers recent advances in transition-metal-catalyzed transformations, such as radical-based cross-coupling of racemic alkyl electrophiles with nucleophiles or racemic alkylmetals with electrophiles and reductive cross-coupling of two electrophiles mainly under Ni/bis(oxazoline) catalysis. C–H functionalization of racemic electrophiles or nucleophiles can be performed in an enantioconvergent manner. Hydroalkylation of alkenes, allenes, and acetylenes is an alternative to cross-coupling reactions. Hydrogen autotransfer has been applied to amination of racemic alcohols and C–C bond forming reactions (Guerbet reaction). Other metal-catalyzed reactions involve addition of racemic allylic systems to carbonyl compounds, propargylation of alcohols and phenols, amination of racemic 3-bromooxindoles, allenylation of carbonyl compounds with racemic allenolates or propargyl bromides, and hydroxylation of racemic 1,3-dicarbonyl compounds.

The pseudo-multicomponent reaction between propargyl amine, an aldehyde and an electron-deficient alkene is described. The C–H activation takes place thermally and allows the obtaining of cycloadducts in very good yields with high diastereoselectivities. The relative configuration is determined by X-ray diffraction analysis of the chiral molecule, obtained as a single diastereoisomer, using a chiral maleimide. A brief study of the stability of the possible ylides involved in the process is also mentioned, confirming the high diastereoselectivity observed. The high functional group density of these cycloadducts permits the synthesis of complex heterocycles. After allylation or propargylation of the pyrrolidine nitrogen atom, RCM-DA cycloaddition or cyclotrimerization with an alkyne is studied, respectively. In this last example, the resulting tetracyclic structures are of potential interest as drugs for the treatment of cystic fibrosis.

This review covers the recent developments (since 2015) of enantioselective desymmetrization reactions using metal-catalyzed, organocatalyzed and enzymatic processes of prochiral and meso-compounds. This asymmetric strategy has been applied to a great number of organic compounds such as diarylalkanes, silanes, alcohols, amines and dibenzylmethylamines, as well as unsaturated compounds comprising dienes, diynes and cyclohexenes. The classical desymmetrization of 1,2-, 1,3-diols and other polyols by inter- and intramolecular acylation and alkylation reactions, but also by oxidation methods are important processes. Carbonyl compounds such as cycloalkanones, cyclohexadienones, cyclic and acyclic 1,3-diketones, cyclic 1,4-diketones are desymmetrized and applied to the synthesis of a wide range of natural products. In the case of dicarboxylic acid derivatives, diesters and lactones, anhydrides, diamides and dinitriles are mainly desymmetrized by intra- and intermolecular esterifications and hydrolysis. Small ring carbocycles such as cyclopropanes and cyclopropenes, cyclobutanes and cyclobutenes, and also cyclopentanes and cyclopentenes, cyclohexanes and cyclohexenes are considered. Heterocyclic systems such as small ring oxygen containing epoxides, oxetanes and oxabenzonorbornadienes as well as nitrogen containing aziridines, azetidines, azabenzonorbornadienes and diazanorbornenes are desymmetrized mainly by asymmetric ring opening reactions. The synthetic applications of these desymmetrization methodologies in the total synthesis of natural products and biologically active compounds are highlighted.

The synthesis of 4-arylthiazol-2(3H)-ones is reported employing a novel and mild methodology using benign solvents. In a second objective the multicomponent preparation of 5,5’-methylenebis[4-arylthiazol-2(3H)-ones] is described following the same strategy. The analysis of the mechanism is also studied and confirmed using chemical tests.

Transition metal-catalyzed reactions of N-sulfinyl imines with several substrates lead to the corresponding chiral amines with high yields and diastereo- or enantioselectivities. As metals, titanium, copper, ruthenium, rhodium, palladium and silver have been successfully used as catalysts in different carbon–carbon forming reactions as well as hydrogenations with molecular hydrogen or transfer hydrogenations with isopropanol as hydrogen source.

The synthesis of nitrogen-containing heterocycles, including natural alkaloids and other compounds presenting different types of biological activities have proved to be successful employing chiral sulfinyl imines derived from tert-butanesulfinamide. These imines are versatile chiral auxiliaries and have been extensively used as eletrophiles in a wide range of reactions. The electron-withdrawing sulfinyl group facilitates the nucleophilic addition of organometallic compounds to the iminic carbon with high diastereoisomeric excess and the free amines obtained after an easy removal of the tert-butanesulfinyl group can be transformed into enantioenriched nitrogen-containing heterocycles. The goal of this review is to the highlight enantioselective syntheses of heterocycles involving the use of chiral N-tert-butanesulfinyl imines as reaction intermediates, including the synthesis of several natural products. The synthesis of nitrogen-containing heterocycles in which the nitrogen atom is not provided by the chiral imine will not be considered in this review. The sections are organized according to the size of the heterocycles. The present work will comprehensively cover the most pertinent contributions to this research area from 2012 to 2020. We regret in advance that some contributions are excluded in order to maintain a concise format.

The synthesis of complex spiro{pyrrolidine-3,1'-pyrrolo[3,4-c]pyrrole} skeleton employing mild conditions is presented. The order of addition of a primary amine, two equivalents of the corresponding maleimide and finally, the aldehyde is of a paramount importance to obtain these final compounds in very high yields. The mechanism is studied performing very simple tests, the Michael type addition of the amine onto the maleimide being the key step. Interestingly, the hybrid scaffold is prepared by sequential addition of two different maleimides. In addition, a more interesting architecture is prepared through a metathesis reaction between allylic residues bonded in the molecule precursor.

Esta tesis describe el estudio de la aplicación en síntesis de N-terc-butanosulfinil derivados de alquil, alquenil, homoalil y homopropargil aminas como intermedios para acceder a moléculas orgánicas de mayor complejidad. Por un lado, se ha estudiado la adición de compuestos organomagnesianos y organolíticos a N-terc-butanosulfinil iminas, y los distintos derivados de aminas que se obtienen como resultado se han usado como precursores de alcaloides pirrolodínicos y piperidínicos, así como para acceder a anillos tipo azepano. Por otro lado, también se presentan aplicaciones en síntesis de N-terc-butanosulfinil homoalil y homopropargil aminas, que pueden participar en reacciones de oxidación allílica y cicloadiciones [2+2+2], respectivamente, para dar lugar a compuestos polifuncionalizados, en el caso de los derivados de homoalil aminas, y derivados de 9-amino-9, 10-dihidrofenantrenos y 1,2,3,4-tetrahidroisoquinolinas, en el cado de los derivados de homopropargil aminas.

In this account the reactions of chiral N-tert-butylsulfinyl imines with organometallic reagents such as organoalkaline (lithium, sodium, potassium and cesium derivatives), organomagnesium, organozinc, organoboron, organoaluminium, organoindium and organosilicon compounds is comprehensively described. The reactivity in all cases is derived to synthetic applications in order to prepare interesting organic nitrogenated molecules, especially in the field of alkaloid compounds.

The N‐propargylation of enantioenriched homopropargylic amine derivatives 3 proceeds in high yields under basic conditions. The resulting 4‐azaocta‐1,7‐dynes 5 were transformed into 1,2,3,4‐tetrahydrosioquinolines 7 bearing substituents at 3‐, 6‐ and 7‐positions, upon reaction with symmetrical alkynes, through a [2+2+2] cyclotrimerization promoted by Wilkinson catalyst. Ruthenium‐catalyzed ring closing metathesis of azaocta‐1,7‐enynes 9a and 15a gave 1,3‐dienes 10a and 16a, respectively, in high yields. Tetrahydroisoquinolines 12a and 18a, with a substitution pattern in the aromatic ring different to that of compounds 7, were prepared by a [4+2] cycloaddition of dimethyl acetylenedicarboxylate with dienes 10a and 16a, respectively.