A DFT Study of Acetylenic Alkali Metal Thiolates

Quantum-chemical calculations by the density functional theory (DFT) method showed that of acetylenic thiolates and their structural analogs, thioketene or thiirene anions, acetylenic thiolates and thioketene anions are only stable, and the negative charge in them is mostly localized on the sulfur atom.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 7, 2005, pp. 1206–1210.Original Russian Text Copyright © 2005 by Petrov, Belyakov.     

Unusual N,Se-heterocycles with cyclic Se–N+ bond of isoselenazolopurinium type

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Addition of Nitrile Oxides to N-Allylsaccharin

The addition of nitrile oxides to N-allylsaccharin has been studied and it has been shown that the reaction occurs regiospecifically to form a 5-substituted isomer. The molecular structure of 2-{ 5-[(3-methyl)isoxazolin-2-yl]methyl}-3-oxo-2,3-dihydrobenz[d]isothiazole 1,1-dioxide has been determined by X-ray analysis. A feature of the crystal of this compound is the presence of a supersymmetrical crystalline structure with two independent molecules associated by a center of pseudoinversion.Dedicated to Professor V. I. Minkin on the occasion of his anniversary__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 450–456, March, 2005.     

Macrocycle Embrace: Encapsulation of Fluoroarenes by m‐Phenylene Ethynylene Host

We report structural characterization of a new member of m‐phenylene ethynylene ring family. This shape‐persistent macrocycle also co‐crystallizes with hexafluoro‐, 1,2,4,5‐tetrafluoro‐, 1,3,5‐trifluoro, and 1,4‐difluorobenzene. The four complexes are almost isostructural, and all show the fluoroarene included into the central cavity of the macrocycle. Characterized by multiple short C?H???F?C contacts, these inclusion complexes further dimerize in the solid state into a 2+2 assembly, in which the two macrocycles embrace each other by their large hydrophobic groups that are rotated by 60° relative to one another.     

An efficient synthesis of multisubstituted 4-nitrobuta-1,3-dien-1-amines and application in cyclisation reactions

The synthesis of multisubstituted 4-nitrobuta-1,3-dien-1-amines (nitrodienamines) from 3-aminocrotonates and nitroacetaldehyde potassium salt, has been performed in 45–89% yields. This one-step protocol works efficiently with a broad range of N-H and N-substituted 3-aminocrotonates and delivers both primary and secondary nitrodienamines. In addition, the possible variations of the substituents at the positions 2 and 3 of 4-nitrobuta-1,3-dien-1-amine have been shown. Generally, the yields of secondary 4-nitrobuta-1,3-dien-1-amines were lower than those of primary ones. The synthetic usefulness of obtained 4-nitrobuta-1,3-dien-1-amines has also been demonstrated by achieving the synthesis of multisubstituted 5-nitro-1,6-dihydropyridines in two-component cyclocondensation reactions of 4-nitrobuta-1,3-dien-1-amines with aromatic or aliphatic aldehydes. Lastly, diverse N-H and N-substituted 5-nitro-1,6-dihydropyridines have been obtained in 35–87% yields.     

8‐Chloro‐7‐(2,6‐di­chloro­benzyl)‐1,3‐di­methyl‐7H‐purine‐2,6(1H,3H)‐dione

The title compound, C₁₄H₁₁Cl₃N₄O₂, consists of two planar fragments which are nearly perpendicular to one another. The crystal packing is controlled by intra‐ and intermolecular C—H·O hydrogen bonds, and Cl·phenyl‐ring‐centroid and weak stacking interactions.