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Pyridoxal hydrochloride, a vitamin B6 vitamer, was synthetically converted to a series of diverse redox‐active benzoyl pyridinium salts. Cyclic voltammetry studies demonstrated redox reversibility under basic conditions, and two of the most promising salts were subjected to laboratory‐scale flow battery tests involving galvanostatic cycling at 10 mM in 0.1 M NaOH. In these tests, the battery was charged completely, corresponding to the transfer of two electrons to the electrolyte, but no discharge was observed. Both CV analysis and electrochemical simulations confirmed that the redox wave observed in the experimental voltammograms corresponds to a two‐electron process. To explain the irreversibility in the battery tests, we conducted bulk electrolysis with the benzoyl pyridinium salts, affording the corresponding benzylic secondary alcohols. Computational studies suggest that the reduction proceeds in three consecutive steps: first electron transfer (ET), then proton‐coupled electron transfer (PCET) and finally proton transfer (PT) to give the secondary alcohol. 1H NMR deuterium exchange studies indicated that the last PT step is not reversible in 0.1 M NaOH, rendering the entire redox process irreversible. The apparent reversibility observed in CV at the basic media likely arises from the slow rate of the PT step at the timescale of the measurement. [ABSTRACT FROM AUTHOR]

A practical straightforward synthesis of medicinally important NH‐δ‐lactams through the three‐component Castagnoli‐Cushman reaction of 3‐arylglutaconic anhydrides with carbonyl compound and ammonium acetate has been developed. The scope of the protocol has been thoroughly explored paying particular attention to the carbonyl component using wide array of aliphatic and aromatic aldehydes as well as rarely involved cyclic and acyclic ketones. Synthetic potential of prepared compounds was demonstrated by a series of post‐modifications, including unexpected isomerization. [ABSTRACT FROM AUTHOR]

A four‐component one‐pot transformation involving the Passerini reaction, an aldol addition, and a transesterification has been elaborated, providing an access to a library of densely functionalized tartaric acid derivatives. Two modifications of the process have been explored. In the first modification, carboxylic acids and isocyanides were treated with an excess of ethyl glyoxalate leading to the incorporation of two ethyl glyoxalate residues in the resulting post‐Passerini products. The second modification involved the initial reaction of a carboxylic acid, an aryl glyoxal and an isocyanide to form the Passerini adduct. This was followed by the in situ addition of ethyl glyoxalate to produce the second type of post‐Passerini products through aldol addition and transesterification. [ABSTRACT FROM AUTHOR]

A silver(I) triflate‐catalyzed protocol for the post‐Ugi synthesis of tetracyclic spiroindolines has been developed. The protocol worked best for indole‐3‐carbaldehyde‐derived Ugi adducts obtained using anilines and 3‐aryl propiolic acids. Thus, it is complementary to the previous cationic gold‐catalyzed procedure that was developed for analogues Ugi substrates derived from aliphatic amines and 3‐alkyl propiolic acids. Furthermore, we have demonstrated that under our new settings this domino Friedel‐Crafts ipso cyclization / imine trapping process could be efficiently combined with the preceding four‐component Ugi reaction into a two‐step one‐pot transformation. [ABSTRACT FROM AUTHOR]

A small set of N,O‐chelated isoquinoline‐enol boron complexes featuring an aryl bromide functionality was prepared and employed in palladium‐catalyzed Suzuki couplings with arylboronic acids and bis(pinacolato)diboron. This allowed to obtain two new series of functionalized N,O‐chelated boron complexes and a novel type of bis‐fluorophore hybrid. The optical properties of all obtained complexes were assessed in solid state and in dichloromethane solution. [ABSTRACT FROM AUTHOR]

A gold‐catalyzed post‐Ugi cascade transformation for the synthesis of 2‐pyridones is described. The process involves furan–alkyne cyclization followed by furan ring‐opening and cleavage of the isocyanide‐originated fragment. The initially formed cis double bond can isomerize into a more stable trans double bond upon prolonged exposure to a strong Brønsted acid. Thus, the overall strategy provides a viable access towards two types of 2‐pyridones. [ABSTRACT FROM AUTHOR]

A copper(I) bromide‐catalyzed reaction of A3‐coupling‐derived propargylamines with ethyl buta‐2,3‐dienoate for the fast assembly of a 1,6‐dihydropyridine core is described. The developed protocol was tested on a variety of secondary propargylamines and the possibility of a one‐pot synthesis of 1,6‐dihydropyridine through the A3‐coupling and subsequent ethyl buta‐2,3‐dienoate incorporation was investigated. A copper(I) bromide‐catalysed reaction of A3‐coupling‐derived propargylamines with ethyl buta‐2,3‐dienoate for the fast assembly of a 1,6‐dihydropyridine core is described. The possibility of a one‐pot synthesis of 1,6‐dihydropyridine through the A3‐coupling and subsequent ethyl buta‐2,3‐dienoate incorporation was investigated. [ABSTRACT FROM AUTHOR]

A one-pot procedure involving a four-component Ugi reaction followed by an intramolecular Diels-Alder reaction/HCl elimination cascade has been developed to provide rapid access to the isoindolinone framework in a diversity-oriented fashion. The scope of the process has been investigated with respect to all four components, and a comparison between the one-pot and sequential approaches is given. The possibility of a late-stage one-pot functionalization through Suzuki coupling has been explored. [ABSTRACT FROM AUTHOR]

A series of O,O-chelated boron complexes was prepared through a four-component Ugi reaction followed by complexation of the resulting 1,3-dicarbonyl compounds with boron trifluoride diethyl etherate. The optical properties of these novel luminophores were investigated by UV/Vis spectroscopy and spectrofluorometry, revealing pronounced aggregation-induced emission (AIE) features. [ABSTRACT FROM AUTHOR]

A copper-catalyzed two-step one-pot procedure for the synthesis of thiazolidine-2-thiones has been developed. The process involves a three-component coupling of an alkyne, an aldehyde, and an amine (A3-coupling) followed by trapping the resulting propargylamine with carbon disulfide and subsequent cyclization. [ABSTRACT FROM AUTHOR]

A three‐step synthetic route towards enantioenriched tricyclic tetrahydroquinoline derivatives has been investigated. The first step involved the assembly of 4‐amino‐tetrahydroquinoline core through the asymmetric three‐component Povarov reaction of benzyl (E)‐prop‐1‐en‐1‐ylcarbamate and p‐anisidine with aliphatic aldehydes of various length bearing protected hydroxyl group. The alcohol was then deprotected and employed in an intramolecular reaction with a secondary amine of tetrahydroquinoline moiety producing desired tricyclic scaffolds. [ABSTRACT FROM AUTHOR]

A comprehensive study on gold- and silver-catalyzed cycloisomerizations of hydroxypropargylamides into oxazepines is described. Three different types of hydroxypropargylamide substrates derived from either amide coupling or Ugi reactions have been validated resulting in establishment of selective and general access to a medium-ring oxazepine core. [ABSTRACT FROM AUTHOR]

A cascade transformation involving the Ugi reaction followed by 5-endo-dig carbocyclization and retro-Claisen fragmentation providing access to a 1H-pyrrol-2(5H)-one core is described. The operating protocol is very similar to the typical Ugi reaction settings, while the overall outcome results from the application of a 3-substituted propiolic acid and a phenylglyoxal as acid and aldehyde components, respectively. The utility of process is demonstrated through the synthesis of a small library of 5-oxo-2,5-dihydro-1H-pyrrole-2-carboxamides. [ABSTRACT FROM AUTHOR]

A comparative study on transition metal-catalyzed cycloisomerizations of propargylic ureas derived in situ from secondary propargylic amines and tosyl isocyanate was performed. The influence of catalytic system on the reaction outcome was thoroughly studied on two model examples resulting in the establishment of two selective protocols for both O- and N-cyclizations. The application of cationic gold(I) catalysis generally resulted in a formation of oxazolidin-2-imines as major products while the application of silver(I) triflate selectively provided the corresponding imidazolidin-2-ones. An attempt to rationalize the observed chemoselectivity is described. The scope of both processes was demonstrated through the use of variously substituted secondary propargylic amines. [ABSTRACT FROM AUTHOR]

An efficient procedure for the synthesis of the azocino[5,4- b]indole framework is presented, relying on a cationic gold-catalyzed intramolecular alkyne hydroarylation of propargylic amides derived from various tryptamines and 3-substituted 2-propynoic acids. The triphenylphosphinegold(I) chloride/silver(I) triflate catalytic system was found to be superior to our previously described mercury(II) triflate catalyst, and hence the substrate scope of the process was significantly expanded. [ABSTRACT FROM AUTHOR]

Cover Feature: Three-Component Castagnoli-Cushman Reaction of 3-Arylglutaconic Acid Anhydrides, Carbonyl Compounds, and Ammonium Acetate: a Quick and Flexible Way to Assemble Polysubstituted NH- -lactams (Eur. J. Org. The way chemical building blocks are united to form the desired heterocyclic product is compared to the famous tile-matching Tetris game. B The Cover Feature b shows the synthesis of I NH i - -lactams through three-component Castagnoli-Cushman reaction of 3-arylglutaconic anhydrides with carbonyl compound and ammonium acetate. [Extracted from the article]

Cover Feature: Four-Component One-Pot Process Involving Passerini Reaction Followed by Aldol Addition and Transesterification (Eur. J. Org. B The Cover Feature b shows a novel four-component one-pot transformation that makes use of carboxylic acids, isocyanides, aryl glyoxals, and ethyl glyoxalate to assemble densely functionalized tartaric acid derivatives. More information can be found in the Full Paper by A. A. Peshkov, V. A. Peshkov et al. GLO:5AG/23jun20:ejoc202000798-toc-0001.jpg PHOTO (COLOR): . gl B The Cover Feature b shows a novel four-component one-pot transformation that makes use of carboxylic acids, isocyanides, aryl glyoxals, and ethyl glyoxalate to assemble densely functionalized tartaric acid derivatives. [Extracted from the article]

The Front Cover shows a new method for the fast assembly of 1,6‐dihydro-pyridine core through a copper(I) bromide‐catalyzed reaction of A3‐coupling‐derived propargylamines with ethyl buta‐2,3‐dienoate. The overall transformation involves the addition of secondary propargylamines to ethyl buta‐2,3‐dienoate and subsequent cycloisomerization of resulting 1,5‐enynes. The dancing couple serves as a metaphorical representation of the process under-lying the alliance of science and art. More information can be found in the Full Paper by O. P. Pereshivko, V. A. Peshkov et al. [ABSTRACT FROM AUTHOR]

Shine bright like a dAIEmond! A series of new O,O ‐ chelated boron complexes has been prepared through a four ‐ component Ugi reaction followed by the complexation of the resulting 1,3 ‐ dicarbonyl compounds with boron trifluoride diethyl etherate. The optical properties of these novel luminophores have been assessed, revealing pronounced aggregation ‐ induced emission (AIE) features. The photoluminescence quantum yields for the solid samples were observed in the range of about 0.80–1.00, placing them among the most efficient boron ‐ based luminophores. More information can be found in the Communication by Vsevolod   A. Peshkov, Olga   P. Pereshivko et   al. on page   825 in Issue 8, 2017 (DOI: 10.1002/asia.201700051). [ABSTRACT FROM AUTHOR]

The microwave-assisted title reaction between N-protected 2-(2-bromoaryl)alkylpropargylamides and organo-boron compounds gives the corresponding 3-benzazepin-2-ones. [ABSTRACT FROM AUTHOR]

The article presents chemical equations related to the article "Diversification of the 3-Benzazepine Scaffold Applying Ugi/Reductive Heck Sequence" by A.A. Peshkov and others, published in the periodical "Tetrahedron" in 2015.

The simple procedure is carried out with equimolar amounts of substrates and affords a series of highly functionalized pyrrole structures. [ABSTRACT FROM AUTHOR]

An abstract of the article "Unexpected Regio- and Chemoselectivity of Cationic Gold-Catalyzed Cycloisomerizations of Propargylureas: Access to Tetrasubstituted 3,4-Dihydropyrimidin-2(1H)-ones" by Olga P. Pereshivko, Anatoly A. Peshkov, Luc Van Meervelt, and Erik V. Van der Eycken is presented.

Application of cationic Au(I) catalysis generally results in the formation of oxazolidin product (III) as a major one while the application of AgOTf selectively provides the N-cyclized imidazolidin (IV). [ABSTRACT FROM AUTHOR]

A novel microwave-assisted protocol is developed to give the title products in varying yields depending on the substitution pattern of the substrates. [ABSTRACT FROM AUTHOR]

The AuCl(PPh3)/AgOTf catalyst system efficiently replaces the previously published Hg(OTf)2 catalyst. [ABSTRACT FROM AUTHOR]

A base-promoted 3-alkylation of title compounds (I) with malonate esters (II) affording the corresponding 3-alkylated derivatives (III) is described. [ABSTRACT FROM AUTHOR]