Electrochemical Synthesis of 3-(Sulfonyl)quinol-4-ones from -Alkynyl--(formyl)anilides and Sulfinates.

Electrolysis of -alkynyl--(formyl)anilides and sodium sulfinates on graphite electrodes delivers biologically sound 3-(sulfonyl)quinol-4-ones with moderate to good yields. The reaction is carried out in an undivided cell in the presence of silver(I) oxide with potassium iodide or sodium tetrafluoroborate as the supporting electrolyte. The reaction tolerates variously substituted anilides as well as aryl and alkyl sulfinates.

Total synthesis of the taraxacine A natural product Ag(I)-catalysed imidate-alkyne cyclization.

A domino approach towards β-carboline natural product taraxacine A and its analogues was developed. The main step relies on a silver(I) and base co-catalysed imidate-alkyne cyclization. The reaction tolerates primary and secondary alcohols, and various substitutions in the indole are possible.

Synthesis of Technetium Carboxylates: Wheel-Like Octanuclear Clusters (Tc(μ-O)(RCOO), Where R = CF, CH)─Potential Nanobuilding Units for Tc-MOFs.

Herein, we studied the behavior of TcO in trifluoroacetic anhydride (TFAA) under visible light irradiation in situ by UV-vis spectroscopy. One carboxylate of Tc(VII) CFOTc () and two wheel-like carboxylate clusters of Tc(IV) Tc(μ-O)(CFCOO) (, ) and Tc(μ-O)(CHCOO) () were synthesized and analyzed using pXRD, TGA, UV-vis spectroscopy, and SCXRD techniques. According to SCXRD, it was found that Tc(IV) trifluoroacetate exists in two crystalline modifications.

Application of the intramolecular Diels-Alder vinylarene (IMDAV) reaction for the synthesis of benzo-, carbocyclo-, thienothiopheneisoindolecarboxylic acids and its limitations.

Thienylallylamines, readily accessible from the corresponding thienyl aldehydes, react with maleic and trifluoromethylmaleic anhydrides leading to the formation of acids with a thieno[2,3-]isoindole core. The reaction sequence involves two successive steps: acylation of the nitrogen atom of the initial allylamine and the intramolecular Diels-Alder vinylarene (IMDAV) reaction. The scope and limitations of the proposed method were thoroughly investigated.

Influence of the organic cation on the formation of hexahalotechnetates: X-ray, thermal and comparative analyses of non-covalent interactions.

In this work, we have reviewed non-covalent interactions in technetium hexahalide compounds and obtained eight new compounds of the CatTcHal type, where Cat = dimethylammonium, tetramethylammonium, caffeinium, benzothiazolium, nicotinamidium, and pyrazolium, and Hal = Cl, Br. SCXRD studies were carried out for new compounds. In some compounds, halide anions and/or crystallization water were present.

Domino Three-Component -Acylation/[4 + 2] Cycloaddition/Alder-ene Synthesis of Polysubstituted Benzo[]isoindole-4-carboxylic Acids.

Diversely substituted, partially saturated benzo[]isoindole-4-carboxylic acids were synthesized by a new three-component reaction (3CR) starting from cinnamic amines (3-arylallylamines), maleimides, and maleic anhydride. The process consists of -acylation of the amines by maleic anhydride, intramolecular [4 + 2] cycloaddition in vinylarenes (the IMDAV reaction), and the concluding Alder-ene reaction between Diels-Alder intermediates and maleimides. All of the reaction steps proceed in a highly regio- and stereoselective manner, furnishing five adjacent chiral centers and leading to a single diastereoisomer of the title compound.

Synthesis, crystal structure and Hirshfeld surface analysis of bis-(caffeinium) hexa-chlorido-platinum(IV) in comparison with some related compounds.

The mol-ecular and crystal structure of the title compound, (CHNO)[PtCl], synthesized from hexa-chloro-platinic acid and caffeine in methanol, was studied by single-crystal X-ray diffraction. The caffeinium cations form a double layer hydrogen bonds and π-stacking inter-actions. The Hirshfeld surface analysis showed that the largest contribution to the crystal packing is made by H⋯H (31.

Intramolecular Re···O Nonvalent Interactions as a Stabilizer of the Polyoxorhenate(VII).

The first polyoxorhenate(VII) compound, pyrazolium polyoxorhenate ((CNH)ReO), and two new rhenium(VII) and technetium(VII) salts have been synthesized and studied. The structure of TcO has been reinvestigated. The [ReO] polyoxoanion contains four Re(VII) atoms: one with an octahedral environment and three with a tetrahedral environment.

Domino Approach for the Synthesis of Pyridinium Salts and 1,2,3,8-Tetrahydroimidazo[1,2-]pyridines from 2-Imidazolines and Propiolic Acid Esters.

Adducts of 1-alkyl-2-imidazolines and two molecules of alkyl propiolate, possessing an -propargyl-β-enaminoester fragment, easily undergo a domino reaction to form pyridinium salts with β-(alkylammonio)ethyl group at the nitrogen atom in the presence of 2 equiv of a protic acid. Treatment of the above reaction mixture with a base gives 1,2,3,8-tetrahydroimidazo[1,2-]pyridines. Reaction of the latter compounds with acid chlorides affords pyridinium salts with β-(alkylamido)ethyl moiety at the nitrogen atom.

Crystal structure and Hirshfeld surface analysis of 2,5-di-imino-8a-methyl-4,9-bis-(4-methyl-phen-yl)-7-oxo-6-phenyl-deca-hydro-2-3,8-methano-pyrano[3,2-]pyridine-3,4a-dicarbo-nitrile ,-di-methyl-formamide monosolvate.

In the title compound, CHNO·CHNO, the bi-cyclo[3.3.1]nonane ring sys-tem adopts a half-chair/twist-boat conformation, with the phenyl rings in equatorial orientations with respect to the piperidine ring.

Synthesis, crystal structure and Hirshfeld surface analysis of di-μ-iodido-bis-[(2,2'-bi-quinoline-κ ,')copper(I)].

The mol-ecular and crystal structures of the title compound, [CuI(CHN)], were examined by single-crystal X-ray diffraction and Hirshfeld surface analysis. The Cu atom is coordinated in a distorted tetra-hedral geometry by two N atoms from the 2,2'-bi-quinoline ligands and the two μ-bridging iodide ligands. The mol-ecules are in contact π-π-stacking inter-actions.

Influence of Substituents in a Six-Membered Chelate Ring of HG-Type Complexes Containing an N→Ru Bond on Their Stability and Catalytic Activity.

An efficient approach to the synthesis of olefin metathesis HG-type catalysts containing an N→Ru bond in a six-membered chelate ring was proposed. For the most part, these ruthenium chelates can be prepared easily and in high yields based on the interaction between 2-vinylbenzylamines and (the common precursor for Ru-complex synthesis). It was demonstrated that the increase of the steric volume of substituents attached to the nitrogen atom and in the α-position of the benzylidene fragment leads to a dramatic decrease in the stability of the target ruthenium complexes.

New Preparative Approach to Purer Technetium-99 Samples-Tetramethylammonium Pertechnetate: Deep Understanding and Application of Crystal Structure, Solubility, and Its Conversion to Technetium Zero Valent Matrix.

Tc is one of the predominant fission products of U and an important component of nuclear industry wastes. The long half-life and specific activity of Tc (212,000 y, 0.63 GBq g) makes Tc a hazardous material.

Thiourea as a Stabilizer of Reduced Forms of Technetium─Tc(III) and Tc(IV): Experimental and Theoretical Studies of Complexes.

This paper presents synthetic methods for the preparation of Tc(III) and Tc(IV) coordination compounds with thiourea. We have shown that the main product of the synthesis is the complex [TcTuX]X, (Tu = (NH)CS, X = Cl, Br) and not [TcTu]Cl·4HO, as previously thought. Tu[TcX]X·3HO is the main technetium-containing byproduct of the reaction.

New O- and N-N-Bridging Complexes of Tc(V), the Role of the Nitrogen Atom Position in Aromatic Rings: Reaction Mechanism, Spectroscopy, DTA, XRD and Hirshfeld Surface Analysis.

In this work, O- and N-N-bridging complexes of technetium (V), previously known only for rhenium, were obtained for the first time. Tc(V) complexes with pyridazine (pyd), 1,2,4-triazole (trz), 3,5-dimethylpyrazole (dmpz) and pyrimidine (pyr) were obtained. In three complexes [{TcOCl}(μ-O)(μ-pyd)], [{TcOCl}(μ-O)(μ-trz)]·Htrz·Cl and [{TcO(dmpz)}(μ-O)(TcOCl)] two technetium atoms are linked by a Tc-O-Tc bond, and in the first two, Tc atoms are additionally linked by a Tc-N-N-Tc bond through the nitrogen atoms of the aromatic rings.

Crystal structure and Hirshfeld surface analysis of 5-amino-5'-bromo-2'-oxo-2,3-di-hydro-1-spiro-[imidazo[1,2-]pyridine-7,3'-indoline]-6,8-dicarbo-nitrile dimethyl sulfoxide disolvate.

In the title compound, CHBrNO·2CHOS, the 1,2,3,7-tetra-hydro-imid-azo[1,2-]pyridine ring system and the oxindole moiety are both nearly planar [maximum deviations = 0.042 (2) and 0.115 (2) Å, respectively] and their planes form a dihedral angle of 86.

Novel Synthesis Methods of New Imidazole-Containing Coordination Compounds Tc(IV, V, VII)-Reaction Mechanism, Xrd and Hirshfeld Surface Analysis.

In this work, we have proposed two new methods for the synthesis of [TcOL] (where L = imidazole (Im), methylimidazole (MeIm)) complexes using thiourea (Tu) and Sn(II) as the reducing agents. The main and by-products of the reactions were determined, and possible reaction mechanisms were proposed. We have shown that the reduction of Tc(VII) with thiourea is accompanied by the formation of the Tc(III) intermediate and further oxidation to Tc(V).

Towards Anion Recognition and Precipitation with Water-Soluble 1,2,4-Selenodiazolium Salts: Combined Structural and Theoretical Study.

The synthesis and structural characterization of a series of supramolecular complexes of bicyclic cationic pyridine-fused 1,2,4-selenodiazoles with various anions is reported. The binding of trifluoroacetate, tetrachloroaurate, tetraphenylborate, perrhenate, and pertechnetate anions in the solid state is regarded. All the anions interact with selenodiazolium cations exclusively via a pair of "chelating" Se⋯O and H⋯O non-covalent interactions, which make them an attractive, novel, non-classical supramolecular recognition unit or a synthon.

Crystal structure and Hirshfeld surface analysis of 5-acetyl-2-amino-4-(4-bromo-phen-yl)-6-oxo-1-phenyl-1,4,5,6-tetra-hydro-pyridine-3-carbo-nitrile.

The crystal structure of the title compound, CHBrNO, was determined using an inversion twin. Its asymmetric unit comprises two crystallographically independent mol-ecules ( and ) being the stereoisomers. Both mol-ecules are linked by pairs of N-H⋯O hydrogen bonds, forming a dimer with an (16) ring motif.

Synthesis, crystal structure and Hirshfeld surface analysis of 2-(perfluoro-phen-yl)acetamide in comparison with some related compounds.

The mol-ecular and crystal structures of the title compound, CHFNO, were examined by single-crystal X-ray diffraction and Hirshfeld surface analysis. The title compound was synthesized by a new method at the interface of aqueous solutions of LiOH and penta-fluoro-phenyl-aceto-nitrile. In the crystal, hydrogen bonds and π-halogen inter-actions connect the mol-ecules into double layers.

5,5-Di-chloro-6-hy-droxy-dihydro-pyrimidine-2,4(1,3)-dione: mol-ecular and crystal structure, Hirshfeld surface analysis and the new route for synthesis with Mg(ReO) as a new catalyst.

The mol-ecular and crystal structures of the title compound, CHClNO, were investigated by single-crystal X-ray diffraction and a Hirshfeld surface analysis. The title compound was synthesized by a new type of reaction using Mg(ReO) as a new catalyst and a possible mechanism for this reaction is proposed. The six-membered ring adopts a half-chair conformation.