Reaction of electron deficient NN bonds with acyloxyketenes and mesoionic 1,3-dioxolium-4-olates: fast equilibrium between acyloxyketenes and mesoionic 1,3-dioxolium-4-olates

Reaction of azodicarboxylates with acyloxyketenes arising from dehydrochlorination of acyloxyphenylacetyl chlorides was carried out to give triacylamidine derivatives in good yields. The same triacylamidine derivatives were also obtained in good yields from the reaction with mesoionic 1,3-dioxolium-4-olates generated by Rh₂(OAc)₄-catalyzed decomposition of phenyldiazoacetic anhydride derivatives. Formation of the same compounds from different starting materials is explained by 1,3-dipolar addition between electron deficient NN bonds and mesoionic 1,3-dioxolium-4-olates, indicating fast equilibrium between acyloxyketenes and mesoionic 1,3-dioxolium-4-olates.     

Alkylation of 2H-1,2,3-benzothiadiazine 1,1-dioxides. Formation of a new family of mesoionic compounds

Alkylation of 2H-1,2,3-benzothiadiazine 1,1-dioxide and its aromatic ring substituted derivatives was studied in detail. It was found that alkylation took place both at N(2) and N(3) atoms. In the latter case, a series of interesting mesoionic compounds was prepared. Various alkylation conditions were tried, and due to the substantially different solubility of the two products formed in the reactions, the target compounds could be selectively isolated without chromatographic separation.     

Synthesis of 3-[4-(1-Benzofuran-2-yl)-1,3-thiazol-2-yl]-2-(4-aryl)-1,3-thiazolidin-4-one Derivatives as Biological Agents

A protocol for the synthesis of 3-[4-(1-benzofuran-2-yl)-1,3-thiazol-2-yl]-2-(4-aryl)-1,3-thiazolidin-4-one derivatives (5a–e) has been developed from 1-(1-benzofuran-2-yl)-2-bromoethanone (2),which served as a key intermediate for the synthesis of the title compounds. The reaction of compound 2 with thiourea furnished 4-(1-benzofuran-2-yl)-1,3-thiazol-2-amine 3, which upon further reaction with various aromatic aldehydes, gave Schiff bases 4a–e. These Schiff bases, when treated with thioacetic acid in the presence of catalytic amount of anhydrous ZnCl₂, yielded thiazolidinone derivatives 5a–e. All the newly synthesized compounds have been characterized by analytical and spectral data and screened for their antimicrobial and analgesic activity.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

NO(HSO4), a Fairly Ionic Solid

The colourless solid NO(HSO₄), known as “lead‐chamber crystals”, was investigated ever since its first preparation more than two centuries ago. Its overall ionic nature now is confirmed by X‐ray crystallography [Pna2₁, a = 7.3558(4), b = 6.8924(3), c = 7.7017(3) Å, Z = 4]. The next neighbours of the NO⁺ cations are four hydrogensulfate oxygen atoms, forming a distorted square at a distance of about 2.5 Å from the nitrogen atom. The square pattern next to the nitrogen atom is the most widespread coordination figure about an NO⁺ ion in a nitrosyl salt. Depending on the anion, the interaction goes along with a decrease of the N–O stretch's excitation energy.     

Synthesis of 3,3,5,5-tetrabenzyl-1,2,4-trithiol and 1,2-dis(1,3-arylpropan-2-yl)disulfane

Novel sulfur-containing compounds (3a-3c, 4a-4c) were obtained in ethanol with 1,3-diphenyl-2-propanone as the starting material. The advantages of this procedure were mild reaction conditions, simple protocol, and high yields. The structures of the products were characterized by IR, 1H NMR, MS and elementary analysis. The crystal of the new compound 4a belongs to monoclinic, space group C2 with a = 18.727(3), b = 6.5179(9), c = 13.7576(18)Å, β = 131.0610(10)°, V = 1266.2(3)Å3, Z = 2, Dc = 2.136 g/cm3, μ = 1.078 mm-1, F(0 0 0) = 843, R = 0.0490 and wR = 0.1247 for 3211 observed reflection with I > 2σ(I). X-ray analysis reveals that the molecule is not symmetrical, the molecular structure is stabilized by weak π-π stacking interactions, and no classical hydrogen bonds can be observed.     

3-(4,5-二苄硫基-1,3-二硫杂环戊烯-2-亚基)萘吡喃酮的合成、性质及量子化学计算

设计合成了一种新的具有D-π-A体系的有机分子:3-(4,5-二苄硫基-1,3-二硫杂环戊烯-2-亚基)萘吡喃酮,通过UV-vis,1H NMR,13C NMR,TOFMS和IR确定了其结构.初步研究了该化合物的电子光谱、荧光光谱和热稳定性.运用Gaussian 03量子化学程序包,采用密度泛函(DFT)B3PW91的方法优化了其基态几何结构,得到的几何参数与实验结果吻合得很好.研究结果表明,体系中存在着分子内的电荷转移,有较好的荧光性质,为寻找新的发光材料具有一定的实际意义.     

(4-甲基-1,3-二噻烷-2-亚甲基)-1,7-二芳基-1,6-二烯-3,5-二酮的合成

从2,4-戊二酮和1,2,3-三溴丙烷出发合成了一类新的α-羰基二硫缩烯酮类化合物,并以其为底物合成了(4-甲基-1,3-二噻烷-2-亚甲基)-1,7-二芳基-1,6-二烯-3,5-二酮类化合物,通过IR和1H NMR方法对其进行了表征.     

Bis(1,3-dithiol-2-ylidene)-[3.3]paracyclophanes: orthogonal intramolecular charge transfer interaction

A novel donor-cyclophane, orthogonally incorporated 1,3-dithiol-2-ylidene units (DT) to the cyclophane benzene rings, was synthesized in order to observe the intramolecular charge transfer (ICT) between the donor units and the cyclophane benzene rings.     

Synthesis of Geminally Activated 4-(Furan-2-yl)- and 4-(Thiophen-2-yl)-1-nitrobuta-1,3-dienes

The condensation of 3-(furan-2-yl)- and 3-(thiophen-2-yl)prop-2-enals with nitro-substituted CH acids, namely ethyl nitroacetate, nitroacetone, nitroacetophenone, and nitroacetonitrile, afforded a series of geminally activated nitro dienes, 4-(furan-2-yl)- and 4-(thiophen-2-yl)-1-nitrobuta-1,3-dienes. The product structure was confirmed by NMR and IR spectroscopy.

     

Synthesis and characterization of functionalized 1,3-bis(2- alkyltetrazol-5-yl)triazenes

A series of 1,3-bis(2-alkyltetrazol-5-yl)triazenes have been synthesized in high yields by treatment of sodium nitrite and hydrochloric acid with substituted-5-aminotetrazoles. All compounds were fully characterized using IR spectroscopy,~1H NMR and~(13) C NMR spectroscopy and high resolution mass spectrometer(HRMS). Most of these triazenes exhibit good detonation performance comparable with TNT and low melting points ranging from 81°C to 106°C, which are suitable for melt-cast explosives.Among these compounds, 1,3-bis(2-azidoethyltetrazol-5-yl)triazene(2g) displays a low melting point(106°C), moderate onset decomposition temperature(183°C) and good detonation performance(D:7087 m/s; P: 17.6 GPa).     

Cationic photopolymerization of 1,3-di(9-carbazolyl)-2-propanol glycidyl ether

An absorbance probe method was used for the investigation of photolysis of cationic photoinitiators. The rates of the photolysis of diphenyliodonium hexafluorophosphate (DPIH), diphenyliodonium tetrafluoroborate (DPIB), di(tert-butylphenyl)iodonium tetrafluoroborate (DTIB), di(tert-butylphenyl)iodonium bromate (DTIBr), triphenylsulfonium hexafluorophosphate (TPS) and cyclopropyldiphenylsulfonium tetrafluoroborate (CPS) were studied in the presence of acid indicator quinaldine red (QR) in acetonitrile. Diphenyliodonium hexafluorophosphate and triphenylsulfonium hexafluorophosphate showed the highest photolysis rate. Photopolymerization of 1,3-di(9-carbazolyl)-2-propanol glycidyl ether (DCPGE) initiated with the iodonium and sulfonium salts in bulk and in solution was studied. It was established that the highest initial rate of polymerization is characteristic of DCPGE photopolymerization initiated with DPIH and TPS in bulk. The oligomers of DCPGE of number average molecular weight ( ) ranging from 710 to 1220 were obtained in these reactions in bulk and those with ranging from 1300 to 1600 were obtained in solution. Correspondence: Ruta Lazauskaite, Juozas V. Grazulevicius, Department of Organic Technology, Kaunas University of Technology, Radvilenu plentas 19, LT-50254 Kaunas, Lithuania.     

Reaction of carbon disulfide with 2-bromoimidazolium salts. Novel bicyclic mesoionic thiazolo[3,2-a]imidazoles

A new class of thiazolo[3,2-a]imidazole derivatives is obtained in good yields, by reacting 1-methyl-2-bromoimidazolium salts bearing N⁺-CH₂COAr, N⁺-CH₂COMe, N⁺-CH₂COOMe, or N⁺-CH₂CN fragments, with carbon disulfide in the presence of Et₃N at room temperature. The mesoionic structures of these compounds are established by NMR spectroscopy and by single-crystal X-ray analysis.     

Synthesis and molecular structure of 1-(pyrimidin-2-yl)-2-(4-aryl-1,3-thiazol-2-yl)hydrazines

Reactions of some 2-hydrazinopyrimidine hydrochlorides with potassium thiocyanate gave 1-(pyrimidin-2-yl)thiosemicarbazides which underwent Hantzsch condensation with aryl chloromethyl ketones to produce 1-(pyrimidin-2-yl)-2-(4-aryl-1,3-thiazol-2-yl)hydrazine hydrochlorides. The protonation was accompanied by mutually dependent tautomeric rearrangements of heterocyclic fragments.     

Telluranes: potential synthons for charge-transfer complexes (involving hypervalent Te-I bonds) and serendipitous synthesis of the first triphenyl methyl phosphonium salts containing [C4H8TeI4] and [TeI6]anions

Hypervalent Te-I bonds of telluranes (C₄H₈TeI₂, C₅H₁₀TeI₂ and α-Me₂TeI₂) have been utilised to form the charge transfer (CT) complexes (1-3). The reaction of cyclic tellurane (1,1-diiodotetrahydro tellurophene, C₄H₈TeI₂) with I₂/ICl yields C₈H₁₆Te₂I₆ [IC₄H₈TeI-I-I-ITeC₄H₈I] (1); an unusual dinuclear species while the reaction of another cyclic tellurane (1,1-diiodo telluracyclohexane, C₅H₁₀TeI₂) with I₂ yields C₅H₁₀TeI₄ (2) possessing different structural motif than 1. In 2 the iodine molecules are on both sides bonded to iodine atom of hypervalent Te-I bond of C₅H₁₀TeI₂ which is analogous to the structural type present in Me₂TeI₄ (3) obtained by the reaction of α-Me₂TeI₂ with ICl. The reaction of C₄H₈TeI₂ with PPh₃, serendipitously, yields the first triphenyl methyl phosphonium salts [PPh₃Me]₂ ²⁺[C₄H₈TeI₄]²⁻ (4) and [PPh₃Me]₂ ²⁺[TeI₆]²⁻ (5), indicating the oxidation of PPh₃ whereas C₄H₈TeI₂ itself, is converted into [C₄H₈TeI₄]²⁻ and [TeI₆]²⁻ anions. All the complexes 1-5 have been characterised through single crystal X-ray diffraction studies.     

Zur Koordinationschemie des 1,3-Dithiol-2-selon-4,5-diselenolats (dsise) und des 1,3-Dithiol-2-selon-4,5-dithiolats (dmise). Kristall- und Molekülstruktur des Tetrabutylammonium-bis-(1,3-dithiol-2-selon-4,5-diselenolato)nickelat(II) und -(III), [(n-C4H9)4N]2[Ni(dsise)2] und (n-C4H9)4N[Ni(dsise)2]

Coordination Chemistry of 1,3-Dithiole-2-selone-4,5-diselenolate (dsise) and 1,3-Dithiole-2-selone-4,5-dithiolate (dmise). Crystal and Molecular Structure of Tetrabutylammonium bis(1,3-dithiole-2-selone-4,5-diselenolato)nickelate(II) and -(III), [(n-C₄H₉)₄N]₂[Ni(dsise)₂ and (n-C₄H₉)₄[Ni(dsise)₂] Syntheses and properties of metal(II) and metal(III) bis-chelates of 1,3-dithiole-2-selone-4,5-diselenolate (dsise), of the general type (Bu₄N)_n)M(dsise)₂] (n =2 : M = Zn, Cd, Hg, Cu, Ni, Pd; n = 1: M = Ni, Au) are reported and compared with chelates of the isologue 1,3-dichalcogenole-2-chalcogenoe-4,5-dichalcogenolate (i. r., ¹³C-n. m. r., e. p. r., cyclovoltammetric data). The unexpected rearrangement during the syntheses of dsise and 1,3-dithiole-2-selone-4,5-diselenolate (dmise) is characterized by ab-initio SCF calculations. The x-ray structures of (Bu₄N)₂[Ni(dsise)₂] (space group P2₁/c, a = 8.5556(13) Å, b = 15.0009(12) Å, c = 19.696(3) Å, β = 96.018(7)°, V = 2513.9(5) ų, Z = 2) and Bu₄N[Ni(dsise)₂] (space group C2/c, a = 25.133(6) Å, b = 9.828(4) Å, c = 18.104(7) Å, β = 132.81(1)°, V = 3281(2) ų, Z = 4) are given.