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Diethyl mesoxalate, a vicinal tricarbonyl compound, possesses multiple functionalities that facilitate diverse chemical conversions. The central carbonyl group with two ester functionalities exhibits high electrophilicity to accept nucleophilic attacks of various reagents. This unusual electrophilicity enables the reaction with acid amides that are not common nucleophiles in organic syntheses. Condensation with active methylene compounds or amines leads to electron‐deficient alkenes and imines, respectively, which can be transformed into more complex polyfunctionalized compounds by a second nucleophilic addition. Chemical transformations between the central and adjacent ester carbonyls furnish new ring systems that are useful in material and pharmaceutical sciences. The central carbonyl group can also be built into a ring system by reacting with reagents possessing nucleophilic and electrophilic sites. Furthermore, the central carbonyl serves as a dienophile that undergoes cycloaddition to form functionalized heterocyclic compounds in a single step. [ABSTRACT FROM AUTHOR]

A desymmetrizing 1,2‐addition of silicon nucleophiles to biaryl derivatives containing an 2,6‐dicarbaldehyde‐1‐yl unit is reported. The reaction is catalyzed by copper with a triazolium‐ion‐derived N‐heterocyclic carbene as the chiral ligand and makes use of an Si–B reagent as the silicon pronucleophile. The practical methodology furnishes axially chiral aromatic carbaldehydes decorated with a centrally chiral α‐hydroxysilane moiety in moderate to good yields and with high enantio‐ as well as excellent diastereoselectivities. The silicon nucleophile always attacks at the diastereotopic face of either carbonyl group away from the ortho substituent on the phenyl ring at C1 of the 2,6‐dicarbaldehyde‐1‐yl fragment. The resulting axially and centrally chiral products can be further converted into valuable biaryl compounds with hardly any erosion of the enantiomeric excess. [ABSTRACT FROM AUTHOR]

Numerous appropriately substituted pyridyl or phenyl groups serve as a particularly advantageous activation motif for the electrochemical oxidation of amines. Such groups enable a general, mild method for the electrochemical α‐functionalization of tertiary amines across numerous activating groups and amine scaffolds. Notably, the method accommodates an unprecedented range of nucleophile classes, allowing for the introduction of diverse functional groups to the readily prepared amine substrates. The utility of this method is then demonstrated through applications to unsymmetrical bisfunctionalization, site‐selective functionalization of N‐pyridyl amines vs. other activated amines, a formal synthesis of ivosidenib and the diversification of FDA‐approved drugs or natural product substrates. [ABSTRACT FROM AUTHOR]

Convenient synthesis of phosphorus-containing derivatives of succinic acid, which contain functionalized phosphonous, phosphonic, and phosphinic acid moieties have been developed. The nucleophilic addition of bis(trimethylsiloxy)phosphine to diesters of maleic, itaconic, and acetylenedicarboxylic acids proceeds regioselectively to give a number of functionalized phosphonites. Further aminomethylation of these compounds affords various target acid derivatives. The resulting compounds are of interest as promising biologically active substances and water-soluble ligands. [ABSTRACT FROM AUTHOR]

A three-components regioselective synthesis of 3-[2-formamidovinyl(phenyl)amino]-acrylic acid based on an opening of the imidazole ring under the influence of acetylene carboxylic acids esters or cyanophenylacetylene in aqueous acetonitrile in up to 86% yields has been developed. [ABSTRACT FROM AUTHOR]

We have revisited the imine-anion-mediated Smiles rearrangement for the synthesis of ortho -hydroxyphenyl arylketimines. Detailed examinations revealed that migration of various aromatic groups, previously considered to be unsuited to SN Ar-type reactions, such as electron-rich or sterically hindered aromatic groups, can be accomplished by introducing bulky 9-anthryllithium as a nucleophile. Among the aromatic groups examined, naphthyl groups (1- and 2-naphthyl groups) exhibited an excellent performance, and their migration ability was well illustrated by the reaction with less bulky nucleophiles. [ABSTRACT FROM AUTHOR]

Novel library of pyrazole derivatives (6a–k) from substituted 4-dioxaborolanyl-1H-pyrazole and halo benzaldehyde through simultaneous Suzuki reaction, nucleophilic addition, and hydrolysis under moderate reaction conditions. The desired compounds 6a–k have been formed in good to high yield. All the compound structures were characterized by analytical and spectral (1H NMR,13C NMR and MS) studies. Furthermore, the evaluation of biological activity of synthesized molecules. [ABSTRACT FROM AUTHOR]

The effect of periodic acid on oxidation of the quinoline alkaloids bucharaine, foliosidine, evoxine, and dubinidine was studied as a function of their structures and the reaction conditions. Periodic acid in dilute aqueous solutions was shown to form stable gem-diols. The use of a large excess of HIO4 formed gem-diols and aldehydes. O-Methyl derivatives were obtained in aqueous MeOH solutions. [ABSTRACT FROM AUTHOR]

A convenient synthesis of functionalized aminoalkyl organophosphorus compounds bearing 3-, 4- or 5-coordinated phosphorus atom is based on readily available enamines and trivalent phosphorus acid esters. Radical addition of bis(trimethylsiloxy)phosphine to enamines proceeds regioselectively to give aminoalkylphosphonites, and their subsequent functionalization affords various derivatives of the target acids. The nucleophilic addition of hydrospirophosphorane to enamines also proceeds regioselectively to furnish α-aminoalkyl spirophosphoranes containing five-coordinated phosphorus atom. The resulting compounds are of interest as promising biologically active substances and water-soluble ligands. [ABSTRACT FROM AUTHOR]

The mini-review covers the results of the authors on acetylene chemistry achieved within 2022. This unusual format was selected in order to assess the dynamics and effectiveness of the developed approaches in result/time coordinates and the prospects for further research in these areas. The review discusses new reactions of acetylene and its derivatives that generally take place in superbasic media, in which the dual reactivity of the carbon—carbon triple bond (i.e. its ability to exhibit both nucleophilic and electrophilic properties) is most pronounced. The discovered by us reactions are the atom economical (they do not produce side products), energy- and resource-saving (they proceed at room or slightly elevated temperature), do not require transition metal catalysts, and can be implemented using inexpensive available starting compounds. [ABSTRACT FROM AUTHOR]

A simple one-pot method for the synthesis of 2-substituted quinolin-4(1H)-ones from synthetically accessible 2-(2-aryl(alkyl)- 3-oxoindolin-2-yl)-2-phenylacetonitriles was developed. [ABSTRACT FROM AUTHOR]

Catalyst-free addition of diphenylphosphine oxide to 1,4-diorganyl-4-(organylamino)-alk-2-yn-1-ones proceeded chemo-, regio-, and stereoselectively to afford new Z-3-diphenylphosphoryl-1,4-diorganyl-4-(organylamino)alk-2-en-1-ones in up to 75% yield. The synthesized compounds are promising candidates for organic synthesis and pharmaceutical research. [ABSTRACT FROM AUTHOR]

When a mixture containing 1‐halo‐1‐alkyne, a dinucleophilic agent, and a base (Cs2CO3 or K3PO4) was heated in DMF, regio‐ and stereo‐selective nucleophilic addition of the dinucleophilic agent to the acetylenes occurred. This reaction yielded (Z,Z)‐bis(haloalkene), which subsequently underwent Pd‐catalyzed cyclization through C−H bond activation, resulting in the formation of two‐oxygen‐ or ‐nitrogen‐containing hetero‐π‐conjugated compounds. N‐(5‐Hydroxynaphthalen‐1‐yl)methanesulfonamide was treated with 2‐phenyl‐1‐chloroethyne followed by 1‐chloro‐1‐hexadecyne. After these reactions, Pd‐catalyzed double C−H cyclization was employed to produce 1H‐2‐phenyl‐7‐tetradecylbenzofuro[7,6‐g]indole. Notably, this compound transformed into a fan‐shaped structure at 86 °C and transitioned into a smectic A phase characterized by a layered structure. [ABSTRACT FROM AUTHOR]

A convenient synthesis of functionalized phosphorus-substituted derivatives of γ-butyrolactone based on readily available γ-crotonolactone and trimethylsilyl esters of trivalent phosphorus acids has been developed. The addition of bis(trimethylsiloxy)phosphine to γ-crotonolactone proceeds regioselectively to give phosphonites containing γ-butyrolactone moieties, the subsequent functionalization of which leads to a variety of target derivatives. The resulting compounds are of interest as promising biologically active substances and water-soluble ligands. [ABSTRACT FROM AUTHOR]

Synthesis of nitro-substituted [1,2,4]triazolo[1,5-a]pyrimidines based on oxidative cyclization of the corresponding nitropyrimidinyl hydrazones of aromatic aldehydes was developed. The reactions of 2-aryl-6-nitro-[1,2,4]triazolo[1,5-a]pyrimidines and their structural analogs (2-aryl-6,8-dinitro-[1,2,4]triazolo[1,5-a]pyridines) with different C-nucleophiles were studied. Nucleophilic addition to the pyridine and pyrimidine rings carried out under mild base-free conditions gave new stable 1.5-dihydro-[1,2,4]triazolo [1,5-a]-pyridines and 1.5-dihydro-[1,2,4]triazolo[1,5-a]pyrimidines in the yields up to 94%. [ABSTRACT FROM AUTHOR]

The research focused on the photolysis of ortho‐ and para‐substituted aryl azides and the preparation of 2‐arylamino‐substituted azepines. The best results were achieved in 1,4‐dioxane for ortho‐substituted azides and in ethanol for para‐substituted azides, respectively. It was found that reactions with arylamines, which have electron‐donating groups, typically produce higher yields of heterocycles than those with electron‐withdrawing groups. [ABSTRACT FROM AUTHOR]

The article discusses the challenges and opportunities presented by the integration of artificial intelligence (AI) and the Internet of Things (IoT), highlighting the potential benefits for various industries such as healthcare, agriculture, and transportation. It discusses how AI-powered IoT devices can enhance efficiency, productivity, and decision-making processes while also addressing concerns about data privacy and security.

The addition reactions of organometallics such as organolithium reagents, Grignard reagent, organocopper reagents and organoaluminum reagents to aldehydes and ketones are crucial in organic chemistry, and represent one of most classic methods for C―C bond construction. However, such organometallics are limited in their wide applications due to their poor functional group compatibility, sensitivity to water and air and difficulties in storage. As a consequence, the development of new methods with stable, readily available unsaturated hydrocarbons instead of organometallics to participate in various transformations have attracted significant attention. In this article, we primarily focus on the methodology of using unsaturated hydrocarbons converting into catalytic loading of organocopper intermediates under copper-hydride catalysis, instead of traditional stoichiometric amount of organometallics, to implement the addition reactions to aldehydes and ketones. This approach effectively overcomes the limitations associated with traditional methodologies. The introduction of these reactions can enrich and expand the content of nucleophilic addition knowledge in basic teaching processes, broaden students' perspectives and thinking, facilitate their understanding of the current developments in the field, and stimulate their interest. [ABSTRACT FROM AUTHOR]

2H‐arizines are important three‐membered heterocycles in organic chemistry. Recently, many advances in the synthesis and functionalization of 2H‐arizines have been reported. Neber rearrangement, isomerization of isoxazole, oxidation of enamine, C−H bond activation, decomposition of vinyl azide, functionalization of alkyne, and multi‐step synthesis have been developed for the efficient assembly of 2H‐azirines. As versatile and highly strained three‐membered unsaturated heterocycles, 2H‐azirines can be used as distinctive building blocks towards significant functional groups, and have attracted extensive attention for the fabrication of numerous heterocycles. Recent studies have focused on [3+n] ring‐expansion reactions, nucleophilic addition of C=N double bond or continuous nucleophilic addition followed by cyclization, ring‐opening of 2H‐azirines to acyclic compounds, and substitution of sp3‐C−H of 2H‐azirines. One of the most critical challenges is seeking for a selective opening of the specific three bonds of the strained azirine circle, some of what can be achieved on the basis of metal catalyst, photocatalysis, or combination of metal catalyst and photocatalysis. In this review, recent advances involving the synthesis and reactivity of 2H‐arizines accompanied with challenges and breakthroughs are summarized. The review mainly covers the period from 2019 to 2023. [ABSTRACT FROM AUTHOR]

We investigate the introduction of bulky aryl substituents of the biphenyl, terphenyl, and quaterphenyl type at the 6,13 and 5,7,12,14 positions of the pentacene scaffold by reaction of the corresponding quinones with lithium organic reagents. The 1,1′‐biphenyl‐2‐yl substituent could be installed at the 5,7,12,14‐positions and regioselectively either at 6,13 or at the 5,13 positions. The unsymmetrical substitution motif results from concomitant 1,2 and 1,4‐addition to 6,13‐pentacenequinone. A one‐pot protocol leads to isomeric symmetric 6,13‐disubstituted pentacenes and allows installation of two 5′‐phenyl‐[1,1′:3′,1′′‐terphenyl]‐2‐yl substituents. The four new pentacenes differ in crystal packing and photochemical stability. [ABSTRACT FROM AUTHOR]

Urea (H2NCONH2) is a commercially indispensable chemical as a fertilizer and starting material for the manufacture of many other products. Currently, commercial urea can be prepared with an energy‐consuming process by combining liquid ammonia (NH3) and liquid carbon dioxide (CO2) under high‐temperature and high‐pressure conditions. An alternative approach for synthesis of urea may involve electrochemical synthesis reactions that occur under aqueous and ambient conditions. Here, we propose synthesis of urea via nucleophilic addition reaction during an electrochemical CO2 reduction process in NH4HCO3‐containing electrolytes. The urea formation at a rate of 0.11 mmol g−1 h−1 was achieved on a polycrystalline Au electrode (area: 1 cm2) at a potential of −1.4 V (vs. saturated calomel electrode). Furthermore, the detailed investigations including in‐situ spectroscopic analysis and isotopic labeling characterization reveal the capability of producing urea could be mainly attributed to a spontaneous reaction between the NH3 molecule and the CO2⋅− intermediate. This study promotes the exploration of electrochemical synthesis of high‐value‐added products. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Metallacyclopentadienes are important metallacycles and regarded as intermediates in many reactions, therefore, new methods to achieve them are anticipated. In this study, a formal [3+2] method, through the reactions of an osmapentalyne with benzyl carbanions, was developed. The reactions underwent a nucleophilic attack of carbanions to the Os≡C bond, followed by C—H activation to form the five‐membered osmacyclopentadiene ring. Most of the reactions were carried out at room temperature, the substituents on the aromatic rings of benzyl carbanions are diverse, and the resulting products contain an Os—H bond, representing a novel type of 10C‐carbolong complexes. This work provides a new convenient route to construct metallacyclopentadienes, which is expected to further promote the development of such a type of substances. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Metallacyclopentadienes are important metallacycles and regarded as intermediates in many reactions, therefore, new methods to achieve them are anticipated. In this study, a formal [3+2] method, through the reactions of an osmapentalyne with benzyl carbanions, was developed. The reactions underwent a nucleophilic attack of carbanions to the Os≡C bond, followed by C—H activation to form the five‐membered osmacyclopentadiene ring. Most of the reactions were carried out at room temperature, the substituents on the aromatic rings of benzyl carbanions are diverse, and the resulting products contain an Os—H bond, representing a novel type of 10C‐carbolong complexes. This work provides a new convenient route to construct metallacyclopentadienes, which is expected to further promote the development of such a type of substances. [ABSTRACT FROM AUTHOR]

We studied a reaction of chromone‐containing acrylonitriles and cyanoacrylates with acid hydrazides. This reaction turned out to be a method for the synthesis of salicyloyl‐substituted 1,2,4‐triazolo[1,5‐a]pyridines. The synthesis developed is a tandem ring‐opening/double ring‐closing process. This synthetic approach is characterized by low toxic solvents (ethanol, butanol) and mediator (Et3N), 37–84% yields, non‐chromatographic isolation of products, and substrate tolerance (59 examples). [ABSTRACT FROM AUTHOR]

Substituted indoles are important as drugs. A number of valuable indoles have been synthesized via nucleophilic substitution at the 3'‐position of indoles. However, the preparation of an indolylmethyl electrophile containing a tertiary carbon at the 3'‐position and its subsequent nucleophilic substitution are challenging owing to the instability of the electrophile. Herein, we demonstrated the rapid one‐flow synthesis of indoles via sequential 1,2‐addition/nucleophilic substitution of indolyl‐3‐carbaldehydes. The use of a microflow technology helped in suppressing the undesired reactions caused by the unstable intermediates, resulting in significantly higher yields and reproducibility compared to those under batch conditions. A crown ether was effective when 1‐alkylindole‐3‐carboxaldehyde was used as a substrate. However, the crown ether exerted a detrimental effect when 1H‐indole‐3‐carboxaldehyde was used. A total of 15 structurally diverse indole derivatives were obtained in generally acceptable to good yields. [ABSTRACT FROM AUTHOR]

Propynylidene derivatives of dimethyl malonate and Meldrumʼs acid, as well as cross-conjugated enynones, containing Me3Si, Et3Si, and t-BuMe2Si groups reacted with 4-methyl-, 4-methoxy-, and 4-chloro-benzenethiol under basic conditions to give the corresponding addition products with buta-1,3-diene and penta-1,4-dien-3-one fragments with high stereoselectivity. The thiylation products of enyne derivatives of dimethyl malonate and Meldrumʼs acid retain the trialkylsilyl group, whereas the addition of benzenethiols to 5-(tri-alkylsilyl)-1-phenylpent-1-en-4-yn-3-ones is accompanied by desilylation. Some mechanistic features of the described reactions have been established, and methods for the stereoselective synthesis of sulfur-containing polyunsaturated compounds have been developed. [ABSTRACT FROM AUTHOR]

Direct transition-metal free bond activation and bond formation reaction are central to the development of a sustainable and effective strategy for the synthesis of organic molecules. Facile, aerobic, regiospecific, base-mediated transition metal-free, and direct arylation reactions with inexpensive nitroarenes are need to explore. The use of strong base, promotes the vicarious nucleophilic substitution in nitroarenes. Moreover, functional group modification of synthesized nitroarenes compounds can open myriad applications in pharmaceutical and material industries. In this review, we summarize the recent progress achieved in the transition metal-free, base-mediated methodology has been employed for mono arylation, di-arylation, acylation, and aroylation reactions and we cover the research literature from 2013 to 2022. This review article presents the advantages, limitations, mechanistic rationalization, and future perspectives associated with synthetic methodologies. [ABSTRACT FROM AUTHOR]

[Display omitted] Alkyl (2 E)-2-[2-(phenylcarbamoyl)hydrazinylidene]- propanoates were prepared from 3-nitroacrylates and N- phenylhydrazinecarboxamide. Their fine structure was confirmed by NMR and X-ray data. Cytotoxicity and antiviral activity against the A/Puerto Rico/8/34 (H1N1) influenza virus strain in MDCK cell culture were determined for the obtained compounds. [ABSTRACT FROM AUTHOR]

[Display omitted] The reactions of 1-amino-2-nitroguanidine with 3-nitro- acrylates afford aza-Michael adducts. The latter when refluxed in an aqueous alkaline medium undergo elimination of nitrous acid followed by shift of the resulting C=C bond into C=N position giving finally N -substituted alkylpyruvate hydrazones. These compounds can also be prepared in a one-pot procedure; NMR spectroscopy and X-ray diffraction analysis confirmed the existence of the obtained hydrazones as E -isomers. [ABSTRACT FROM AUTHOR]

General method for the annulation of [1,2,5]thiadiazole ring to pyridine and benzene cycle has been developed using sulfur monochloride as a sulfur source. On this basis a number of [1,2,5]thiadiazolo[4,3‐b]pyridines and benzo[c]thiadiazoles were synthesized. The most π‐deficient [1,2,5]thiadiazolo[4,3‐b]pyridines readily react with neutral carbon nucleophiles such as CH‐acids, indoles, pyrrole and phloroglucinol to give 1,4‐adducts. [ABSTRACT FROM AUTHOR]

An available method for a synthesis of N-substituted (E)-2-(diphenylphosphoryl)aziridines with high yields by the reaction of (1,2-dibromoethyl)(diphenyl)phosphine oxide with a number of primary amines, in particular, methyl-, ethyl-, isopropyl-, tert-butyl-, cyclohexyl- and benzylamines at room temperature in the presence of sodium hydroxide, has been developed. The antibacterial activity of the synthesized compounds was evaluated. [ABSTRACT FROM AUTHOR]

The N-functionalized indole is a privileged structural framework in a wide range of bioactive molecules. The nucleophilic addition between indoles with vinylene carbonate proceeded smoothly in the presence of K2CO3 as the catalyst to produce novel indolyl-containing skeletons and 4-indolyl-1,3-dioxolanones in satisfactory to excellent yields (up to >97% yield). Various synthetically useful functional groups, such as halogen atoms, cyano, nitro, and methoxycarbonyl groups, remained intact during the regioselective N-H addition reactions. The developed catalytic system also could accommodate 2-naphthalenol to achieve the target O-H additive product in good yield. [ABSTRACT FROM AUTHOR]

The reaction of 1-methylisoquinoline with ethyl esters of 1-aryl-2-oxalylacetylenes occurs under mild conditions (20–25 °C, without a catalyst) to selectively afford functionalized oxazino[2,3-a]isoquinolines with a yield of up to 88%. [ABSTRACT FROM AUTHOR]

π‐Allyl complexes of transition metals are key species in organometallic chemistry and homogeneous catalysis. Palladium(II) π‐allyl complexes in particular, have gained a lot of attention, but their isoelectronic gold(III) counterparts long remained elusive. However, this situation changed during the last few years. This concept article describes the preparative routes, characterization, structure and reactivity of such species, together with their catalytic applications. The influence of the ancillary ligand at gold, either (P,C)/(N,C)‐cyclometalated or (P,N)‐hemilabile, is analysed in detail. The Au(III) and Pd(II) π‐allyl complexes are also compared to highlight the similarities and differences. [ABSTRACT FROM AUTHOR]

The influence of the electronic and spatial structure of the diene system of 2-benzylidene-3-methyl-4-nitro-2,5-dihydrothiophene-1,1-dioxides on the result of the reaction with semicarbazide in different media (in ethanol and DMSO) was studied. The structure of the obtained compounds was established by IR, 1Н, 13С{1Н}, 1Н–13С HMQC, 1Н–13С HMBC, 1Н–1Н NOESY spectroscopy methods. [ABSTRACT FROM AUTHOR]

Described herein is the development of an organoaluminium‐mediated tandem conjugate addition‐cyclization sequence of p‐quinone monoacetals with 2‐siloxyphenyl Grignard reagents to afford a collection of phenol‐bridged cyclohexanone derivatives. Furthermore, a tandem conjugate‐addition and dimerization reaction of p‐quinone monoacetals with Grignard reagents is also reported to offer a straightforward and diastereoselective synthesis of complex bridged‐ring compounds bearing tricyclo[6.2.2.02,7]dodecene skeletons. [ABSTRACT FROM AUTHOR]

The reactivity of N‐Heterocyclic carbene (NHC)‐bound alkynyl acyl azoliums is underexplored in chemistry. We herein reported an NHC‐catalyzed [3+3] annulation of alkynyl acyl azoliums with β‐keto esters. The strategy features mild reaction conditions and exhibits broad substrates scope, delivering a wide range of tri‐substituted α‐pyrones in moderate to excellent yields (up to 95%). This approach extends the reactivity of alkynyl acyl azoliums to β‐keto esters binucleophiles. [ABSTRACT FROM AUTHOR]

Mannich‐type reactions involving alkylzinc reagents have been developed using different strategies. We show that the addition of these organometallic species to sulfonyl imines occurs upon simple heating and affords Mannich products in moderate to excellent yields (14 examples, 30–99 %). Interestingly, N‐alkyl imines were also found to be suitable partners after activation as an acyliminium by acetyl chloride (12 examples, 49–86 %) or, more originally, by TMSCl (14 examples, 26–87 %). These methods proved complementary, leading to the preparation of both N‐protected secondary or tertiary amines and N‐unprotected secondary amines in good yields, with an increased eco‐compatibility, and under simple conditions. [ABSTRACT FROM AUTHOR]

An oxidant-free and highly efficient synthesis of phenolic quinazolin-4(3H)-ones was achieved by simply stirring a mixture of 2-aminobenzamides, sulfonyl azides, and terminal alkynes. The intermediate N-sulfonylketenimine underwent two nucleophilic additions and the sulfonyl group eliminated through the power of aromatization. The natural product 2-(4-hydroxybenzyl)quinazolin-4(3H)-one can be synthesized on a large scale under mild conditions with this method. [ABSTRACT FROM AUTHOR]

Advancing the development of perfecting the use of polar organometallics in bio‐inspired solvents, we report on the effective generation in batch of organosodium compounds, by the oxidative addition of a C−Cl bond to sodium, a halogen/sodium exchange, or by direct sodiation, when using sodium bricks or neopentylsodium in hexane as sodium sources. C(sp3)‐, C(sp2)‐, and C(sp)‐hybridized alkyl and (hetero)aryl sodiated species have been chemoselectively trapped (in competition with protonolysis), with a variety of electrophiles when working "on water", or in biodegradable choline chloride/urea or L‐proline/glycerol eutectic mixtures, under hydrous conditions and at room temperature. Additional benefits include a very short reaction time (20 s), a wide substrate scope, and good to excellent yields (up to 98 %) of the desired adducts. The practicality of the proposed protocol was demonstrated by setting up a sodium‐mediated multigram‐scale synthesis of the anticholinergic drug orphenadrine. [ABSTRACT FROM AUTHOR]

In this paper, we report a gold(I)‐catalyzed cascade cyclization of N‐ or O‐nucleophile tethered‐vinylidenecyclopropanes (VDCPs), resulting in the synthesis of pyrrole, furan, pyrrolidine, and piperidine skeletons in 30%‐98% yields. Depending on the carbon chain length connecting the nucleophile and VDCPs, two reaction pathways are available, leading to different products. Both α‐amino VDCPs and α‐hydroxyl VDCPs, where nucleophiles and VDCPs are connected by a methylene group, undergo intramolecular nucleophilic addition and aromatization, followed by ring‐opening of the cyclopropane unit to produce substituted pyrroles and furans. By extending the chain length to three or four carbons, it becomes possible to form pyrrolidines and piperidines with a cyclobutene moiety via ring expansion of the cyclopropane unit, accompanied by gold carbene induced vinylogous nucleophilic addition. [ABSTRACT FROM AUTHOR]

Magnetic resonance imaging (MRI) is limited in clinical application due to its low sensitivity. Hyperpolarization technology overcomes this limitation by enhancing molecular MRI signal. At present, ［1-13C］pyruvate is the most important hyperpolarized biological probe, which is widely used in hyperpolarized MRI research. In this study, an efficient two-step sequence of nucleophilic addition reaction and ozonation reaction for synthesis of ［1-13C］pyruvate from 13CO2 was developed, with the yield of 71.5%, and the chemical purity was above 98%. Furthermore, the ozonation reaction was optimized to furnish the one-pot synthesis of ［1-13C］pyruvate in 70.5% yield, and the chemical purity was above 98%. The synthesis of ［1-13C］pyruvate provides a basis for the development of magnetic resonance imaging research.

The aim of this essay is to disclose the similarity of a great variety of reactions that proceed between nucleophiles and π-electrophiles—both aromatic and aliphatic. These reactions proceed via initial reversible addition, followed by a variety of transformations that are common for the adducts of both aliphatic and aromatic electrophiles. We hope that understanding of this analogy should help to expand the scope of the known reactions and inspire the search for new reactions that were overlooked. [ABSTRACT FROM AUTHOR]

The use of N‐alkyl imines in decarboxylative Mannich reaction with substituted malonic acids half oxyesters (SMAHOs) has been developed to afford a direct access to secondary β2,3‐aminoesters. The transformation occurs under very practical conditions (DABCO as a catalyst in bulk toluene and open to air) and can be performed with a broad range of each substrate in yields of 36 to 97 %. Importantly, the reaction was found to require the use of acidic additives in combination with the organocatalyst to limit the competitive olefination reaction. [ABSTRACT FROM AUTHOR]

Reactions of highly electrophilic azolo[b]pyridines with di- and triatomic phenols lead to products of 1,4-addition of C-nucleophiles to the pyridine cycle. It is found that another type of azoloazines, namely [1,2,4]triazolo[1,5-a]pyridines, are also capable to form adducts with polyphenols. Synthesized compounds containing simultaneously several pharmacophoric fragments are of interest as potential biologically active compounds. [ABSTRACT FROM AUTHOR]