Some transformations of 1-(1,2,3,4-tetrahydronaphthylidene)-malononitrile or cyanoacetate

Summary Syntheses of 11-amino-5,6-dihydronaphtho[1,2:4,5]thieno[2,3-d]pyrimidine (8) and its 10-oxide 7 from 2-amino-1-cyano-4,5-dihydronaphtho[2,1-b]thiophene and its derivatives are described. Several open chain tetrahydronaphthylidene derivatives and a substituted pyrimidine derivative9 were also prepared.Dedicated to Professor Dr. K. Gewald on the occasion of his 60th birthday     

1,4‐Methano‐11a‐methyl‐4,4a,11,11a‐tetrahydro‐1H‐benzo­[b]­fluoren‐11‐one

The title compound, C₁₉H₁₆O, crystallizes with two mol­ecules of opposite chirality in the asymmetric unit. In both mol­ecules, the naphthalene and cyclo­pentanone moieties are individually planar. The two cyclo­pentane rings adopt envelope conformations, while the cyclo­hexane ring adopts a boat conformation.     

Synthesis of dithieno[2,3-b:3',2'-d]thiophenes-building blocks for cross-conjugated beta-oligothiophenes

Syntheses of annelated and functionalized beta-trithiophenes (dithieno[2,3-b:3',2'-d]thiophenes), building blocks for the helically annelated, cross-conjugated beta-oligothiophenes, are reported. UV-vis spectra reveal that the effect of octyl substituents on the onset of electronic absorption in annelated beta-trithiophenes is negligible compared to the effect of helical distortion in the higher beta-oligothiophenes.     

Two strong emitting coordination polymers with chain and ladder structures

Two coordination polymers [Zn(Cabo)₂(EtOH)₂(4,4-Bipy)] _n (1), and [Zn₂(Cabo)₂(NO₃)₂(4,4-Bipy)₂] _n (2) (Cabo = carbazolylacetate, 4,4-Bipy = 4,4-bipyridine) with chain and ladder structures, respectively, were prepared and characterized by X-ray single-crystal structural analysis. The results showed that the different anions of metal salts have a large effect on the construction of coordination frameworks. Both complexes show strong emissions in the solid state as well as high thermal stability.     

Cleavage of 1,3-oxathiol-2-one rings withn-butyllithium a new route to alkyl thiolates

1,3-Oxathiol-2-ones are converted byn-butyllithium into alkynyl thiolates.

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Spaltung von 1,3-Oxathiazol-2-on-Ringen mitn-Butyllithium. Ein neuer Weg zu Alkylthiolaten (Kurze Mitteilung)

Zusammenfassung 1,3-Oxathiol-2-one werden mitn-Butyllithium zu Alkinylthiolaten umgesetzt.

     

Helically annelated and cross-conjugated oligothiophenes: asymmetric synthesis, resolution, and characterization of a carbon-sulfur [7]helicene

The synthesis and characterization of a novel oligothiophene, in which the thiophene rings are annelated into a [7]helicene with cross-conjugated pi-system, are described. Such [7]helicenes may be viewed as fragments of the unprecedented carbon-sulfur (C(2)S)(n)() helix, possessing sulfur-rich molecular periphery. Racemic synthesis of [7]helicene is based upon iterative alternation of two steps: C-C bond homocouplings between the beta-positions of thiophenes and annelation between the alpha-positions of thiophenes. Asymmetric synthesis is carried out using (-)-sparteine-mediated annelation of the axially chiral bis(aryllithium) with electrophilic sulfur equivalent. Alternatively, enantiomers of the [7]helicene are obtained via resolution using menthol-based chiral siloxanes. Racemic [7]helicene and four other macrocyclic products of the annelation are characterized by X-ray crystallography. One of the solvent polymorphs of the [7]helicene possesses pi-stacked columns of opposite enantiomers and multiple short intermolecular contacts, including both homochiral and heterochiral short S...S contacts, suggesting an effective intermolecular electronic coupling in two-dimensions. The [7]helicene is configurationally stable at room temperature and racemizes at 199 degrees C with a half-time of about 11 h. Selected physicochemical studies (UV-vis absorption, CD, optical rotation, and cyclic voltammetry) of the [7]helicene are described.     

11‐Methyl‐12a‐phenyl‐9a,12a‐di­hydro­phenanthro­[9′,10:5,6][1,4]­dioxino­[2,3‐d]­thia­zole

In the title compound, C₂₄H₁₇NO₂S, the dioxine and thia­zoline rings are distorted from planarity towards a half‐chair and an envelope conformation, respectively. The configurations of the dioxine ring, the thiazoline ring and the attached phenyl ring are conditioned by the sp³ state of the two bridgehead C atoms. The phenanthrene system is nearly coplanar with the dioxine ring, while the attached phenyl ring is orthogonal to the thia­zoline ring.     

Hexa­methyl­enetetraminium 2,4,6‐tri­nitro­phenolate

In the title complex, the 1:1 ionic adduct of hexa­methyl­enetetraminium and 2,4,6‐tri­nitro­phenolate, C₆H₁₃N₄⁺·­C₆H₂N₃O₇^?, the cation acts as a donor for bifurcated hydrogen bonds to the O atoms of the phenolate and one of the nitro groups of the 2,4,6‐tri­nitro­phenolate anion. The crystal structure is built from sheets of cations and anions, and is stabilized by intermolecular C—H?O and C—H?π interactions.     

The ternary complex 4‐(2‐pyridyl)pyridinium–3,5‐di­nitro­benzoate–3,5‐di­nitro­benzoic acid (1/1/1)

In the title ternary complex, C₁₀H₉N₂⁺·C₇H₃N₂O₆^?·C₇H₄N₂O₆, the pyridinium cation adopts the role of the donor in an intermolecular N—H?O hydrogen‐bonding interaction with the carboxyl­ate group of the 3,5‐di­nitro­benzoate anion. The mol­ecules of the ternary complex form molecular ribbons perpendicular to the b direction, which are stabilized by one N—H?O, one O—H?O and five C—H?O intermolecular hydrogen bonds. The ribbons are further interconnected by three intermolecular C—H?O hydrogen bonds into a three‐dimensional network.