Reactions of [60]Fullerene with Di(azidomethyl) benzenes

Alargenumberofadditionsto[6O]fullerenehavebeeninvestigated.However,mostoftheworkhaveconcentratedontheformationofthemono-additionproductS0f[60]fullerene'-Thedevelopment0fselechveroutestomultipleadductShascurrentlybecomethefrontierinthechendstryof[60]fuIlerene'~'.FollowingtheaPplicahonoftether-directedremotefunctionalizati0ntotheregi0specificformati0nofthedi-andtriadductSof[60]fullerene,F.Diederichetal6alsodescribed'awayforthedirectdifunctionalizationof[60]fullerenebasedonacyclizationreachono…     

2,4-Bis{[6-(2,2-dimethylpropyl)-3-ethyl-1,3-benzothiazol-2(3H)-yl­idene]methyl}cyclobutenediylium-1,3-­diolate

The title compound, C₃₄H₄₀N₂O₂S₂, adopts a trans conformation. The four conjugated Csp²—Csp² single and double bonds of the polymethinic moiety, which bridges both heterocyclic end groups and the central four-membered ring, display nearly equal bond lengths. The mol­ecule is nearly planar, with interplanar angles between the benzo­thia­zole end groups and the central four-membered ring of 6.9 (1) and 7.7 (1)°; the angle between the heterocyclic systems is 1.8 (1)°. The crystal packing involves π-stacking effects, with intermolecular C⃛C distances varying from 3.755 (3) to 3.991 (3) Å.     

2-[Pyridin-2(4)-yl]-N-[ω-vinyloxyalkyl]ethanamines

Russian Journal of Organic Chemistry -     

Influence of amino acid sequence on the interaction of short peptides containing 3-[2-(9-anthryl)benzoxazol-5-yl]-alanine with β-cyclodextrin

The influence of peptide sequence and Leu chirality in linear and cyclic peptides containing 3-[2-(9-anthryl)benzoxazol-5-yl]alanine on interaction with β-cyclodextrin were studied using fluorescence and NMR spectroscopy. The analysis of enthalpy-entropy compensation effect (α=1.05±0.02 and TΔS₀ ⁰=15.1±0.5 kJ mol^?1) indicates that the entropic contribution connected with the solvent reorganization is the major factor governing the peptides-β-cyclodextrin complexation. Moreover, spatial orientation of guest-host molecule depends more than association constant on Leu residue configuration. However, the cyclization of the peptide chain substantially decrease the association constant with β-CD. An analysis of 2D NMR spectra reveals that inclusion complex is formed by penetration of cyclodextrin cavity from wider and narrow rims by anthryl group in the case of Box(Ant)-SPKL or anthryl and Leu residues for Box(Ant)-SPK(D)L analogue.      

Spectral and thermochemical properties of the [Na(H2O)4] [EuL4]·0.775CH2Cl2 complex,HL = 1,3-bis(1,3-dimethyl-1H-pyrazol-4-yl)-1,3-propanedione

Reaction of Eu(NO₃)₃·6H₂O with 1,3-bis(1,3-dimethyl-1H-pyrazol-4-yl)-1,3-propanedione (HL) in the presence of NaOH affords the complex compound [Na(H₂O)₄] [EuL₄]·0.775CH₂Cl₂ (I). The spectral (UV, IR, ¹H NMR spectroscopy), and thermo-luminescent (TG-DSC-MS) properties of the complex I, as well as its fragmentation at the laser desorption ionization (LDI-MS) were studied.     

Synthesis and Reactivity of 2-(Furan-2-yl)benzo[1,2-d:4,3-d′]bis[1,3]thiazole

Russian Journal of Organic Chemistry - Acylation of 1,3-benzothiazol-6-amine with furan-2-carbonyl chloride in propan-2-ol gave N-(1,3-benzothiazol-6-yl)furan-2-carboxamide which was converted to...     

X-Ray Structural Analysis of Ethyl [2,2-dimethyl-6-(Δ2-thiazolin-2-yl)-4H-1,4-benzoxazin-3-one-4-yl]butyrate

With the aim of discovering new molecules with K⁺ channel modulating properties, we have synthesized analogues of cromakalim, an important molecule which shows specific affinity toward the K⁺ channels, by replacing the benzopyrane ring with a benzoxazine moiety. As a part of this study, we have synthesized and characterized, in solution and in the solid state as well, the compound ethyl [2,2-dimethyl-6-(²-thiazolin-2-yl)-4H-l,4-benzoxazin-3-one-4-yl]butyrate (V). This compound exhibits in the solid state the following parameters: molecular formula C₁₉H₂₄N₂O₄S, triclinic, space group , M_w = 376.5, a = 12.581(3) Å, b = 5.485(4) Å, c = 14.612(2) Å, = 91.85(2), = 108.9(3), = 82.04(4), V = 944.7 ų, Z = 2, d = 1.323 g·cm^–3. We describe here the synthesis and discuss the solid-state conformation of this new molecule; when tested on rat aorta ring precontracted with phenylephrine, the compound showed a concentration-dependent relaxation comparable to that measured for cromakalin taken as reference drug.     

Crystal Structure of Catena-poly-[2,2'-bisbenzimidazole Mn(Ⅱ)-μ-Benzene-1,3-dicarboxylato]

The title complex,[(BBI)Mn(BDC)]n 1(BBI = 2,2'-bisbenzimidazole(C14H10N4),BDC=benzene-1,3-dicarboxylate dianion(C8H10O4)),crystallizes in the monoclinic system,space group C2/c,with a=17.822(8),b=16.181(7),c=13.355(6),β=92.112(5)°,V=3848.67(304)3,Z=8,C22H14MnN4O4,Mr=453.31,Dc=1.565 g/cm3,F(000)=1848,μ=0.725 mm-1,S=1.000,the final R=0.0310 and wR=0.0589.1 contains hydrogen bonds and π-π stacking interactions between the neighboring aryl-ring of BBI's,which helps to form a three-dimensional crystal structure.     

Interaction of 1-methyl-1-({2-[4-(trifluoromethyl)phenyl]-1,3-thiazol-4-yl}methyl) piperidinium chloride with β-CD: spectroscopic,calorimetric and molecular modeling approaches

Spectroscopic investigation supported by molecular modeling methods has been used to describe the inclusion complex of β-cyclodextrin (β-CD) with 1-Methyl-1-({2-[4-(trifluoromethyl)phenyl]-1,3-thiazol-4-yl}methyl) piperidinium chloride (1MPTMPC) in solution and in solid state. The formation of inclusion complex between the β-CD and the 1MPTMPC has been investigated both in solution and in the solid state. Solution-state complexation between the 1MPTMPC and β-CD was established using ¹H NMR spectroscopy and isothermal titration calorimetry (ITC). From the ¹H NMR spectroscopic studies, 1:1 complex stoichiometry was deduced with an association constant (K) of 925 M^?1. Using an independent binding model, the ITC technique provides a K value of the same order with the one determined by NMR and the thermodynamic parameters ΔH, ΔS and ΔG which reveals driving forces involved during complex formation. The formation of the solid inclusion compound was confirmed by X-ray powder diffraction and differential scanning calorimetry. The most probable conformation of the inclusion complex obtained through a molecular docking investigation corroborates well to ROESY experiment.     

Synthesis of C-Nucleoside Analogues： 2-[2-（Hydroxymethyl）-1, 3-dioxolan-5-yl]1, 3-thiazole-4-carboxamide and 2-[2-（Mercaptometh-yl）-1, 3-dioxolan-5-yl] 1, 3-thiazole-4-carboxamide

Novel C-nucleosides of tiazofurin analogue (2-[2-(hydroxymethyl)-1,3-dioxolan-5-yl] 1,3-thiazole-4-carboxamide) and its thiol-substituted derivative (2-[2-(mercaptomethyl)-1,3-dioxolan-5-yl] 1, 3-thiazole-4-carboxamide) were synthesized from methyl acrylate through a multistep procedure. Their structures were confirmed by IR, ^1HNMR, ^13CNMR and elemental analysis.     

Synthesis and characterisation of [tris(1,3-dithiole-2-thione-4,5-dithiolato)-stannate]2−, [Q]2[Sn(dmit)3], [tris(1,3-dithiole-2-one-4,5-dithiolato)stannate]2−, [Q]2[Sn(dmio)3] and [tris(1,3-dithiole-2-thione-4,5-selenolato)stannate]2−, [Q]2[Sn(dsit)3], complexes: Analysis of the structural variations of the [Sn(dmit)3]2− and [Sn(dmio)3]2− dianions

[Tris(1,3-dithiole-2-thione-4,5-dithiolato)stannate]²⁻, [Q]₂[Sn(C₃S₅)₃], [tris(1,3-dithiole-2-one-4,5-dithiolato)stannate]²⁻, [Q]₂[Sn(C₃S₄O)₃], and [tris(1,3-dithiole-2-thione-4,5-diselenolato)stannate]²⁻ [Q]₂[Sn(C₃S₃Se₂)₃], complexes, have been synthesised and characterised. Crystal structure determinations of [Q]₂[Sn(C₃S₅)₃] (Q=1,4-dimethylpyridinium, monoclinic and orthorhombic forms; NMe₄, NEt₄, and PPh₄) and [NEt₄]₂[Sn(C₃S₄O)₃] revealed variations in the overall dianion structures. The geometry about tin in each case is essentially octahedral with the chelate bite angles in the range 80.7(5)–87.45(4)°: the range of Sn–S distances is 2.5207(18)–2.571(17) Å. A statistical analysis, carried out on the crystal structure data for the six complexes, indicated that the most critical factors in controlling the overall shape of the dianion were the distances of the Sn atom from the dithiolate ligand planes [Sn–OOP]. Interanionic S⋯S interactions, within the sum of the van der Waals’ radii for two S atoms, are affected by the size of the cation, Q; the secondary connectivity is 3-dimensional for the smallest cations, Q=1,4-dimethylpyridinium and NMe₄, in chains for the somewhat larger cation, NEt₄ and is absent for the still larger, PPh₄ cation.     

Reaction of [VO(OPr)3] with hexamethyldisylthiane in the presence of β-diketones

The reaction of [VO(OPr)₃] (Pr is n-propyl) with hexamethyldisylthiane Me₃SiSSiMe₃ in the presence of β-diketones (acetylacetone (HAcac), hexafluoroacetylacetone (Hfac), and dipivaloylmethane (Dpm)), is studied. In all cases, vanadium(IV) and vanadium(III) β-diketonate complexes of different types are formed. New crystalline modification [V(Acac)₃] is obtained in the reaction with HAcac. The mixedligand vanadium(III) complex of the composition [V₂(Hfac)₂(μ-OPr)]₂ is formed with Hfac. In the presence of Dpm, the known vanadium(IV) complex [V₂O₂(Dpm)₂(μ-OPr)₂] is obtained in which two vanadyl groups VO²⁺ are linked by two bridging propoxy groups. The structures of all products are determined by X-ray diffraction analysis.     

[4+2] Annulation of 3-(2,2-diethoxyethyl)-1,3-dicarbonyl compounds with indoles catalyzed by Brønsted acid ionic liquid for the synthesis of carbazoles

Various carbazoles were synthesized via [4+2] annulation of 3-(2,2-diethoxyethyl)-1,3-dicarbonyl compounds with indoles. A Brønsted acid ionic liquid, [BPy]HSO₄, was proven to be effective catalyst for this reaction. The ionic liquid catalyst can be recycled three times without significant loss of its catalytic activity.     

A Convenient Synthesis of cis and trans-(±)-4-Amino-1-[2-(hydroxyl-methyl)-1,3-oxathiolan-5-yl]-2(1H)-pyrimidinone

A convenient synthesis of cis-(±) isomer 1 and trans-(±) isomer 2 of lamivudine starting from benzoyloxyacetaldehyde and l,4-dithiane-2,5-diol is described. The key steps include chlorination of oxathiolane lactol 5 by SOCl2/DMF, followed by coupling with silylated N4-acetylcytosine and deprotection. The overall yield was 42.6 % and 20.1 %, respectively.     

Synthesis and Characterization of a Noncovalently Linked Porphyrin-[1,2-(1-acridin-10′-yl-2-aza-2-methylprop-1,3-ylene)-fullerene]Dyad

1,2-(1-Acridin-10'-y1-2-aza-2-methylprop-1,3-ylene)fullerene was synthesized firstly and characterized byUV-Vis,~1H NMR,~(13)C NMR and electrospray ionization mass spectroscopy,which is capable of forming a stablecomplex with zinc tetraphenylporphyrin via the axial ligafion.The steady state fluorescence studies show efficientquenching of the zinc tetraphenylporphyrin emission upon axial coordination of acridine attached to C_(60).     

Remote stereocontrol by the sulfinyl group. Diels–Alder reaction of cyclopentadiene with substituted (S)-[2-(p-tolylsulfinyl)styrenes and (S)-[2-(p-tolylsulfinyl)phenyl] vinyl ketones

The ability of a homochiral sulfinyl group at the dienophile to act as a remote stereocontrol inductor in the Diels–Alder reaction with cyclopentadiene has been evaluated. High pressure conditions were required for the reactions of (S)-2-(p-tolylsulfinyl)styrenes 3–5 (E-1,2-disubstituted double bond) and 6–8 (1,1-disubstituted double bond). A good facial selectivity and total endo selectivity were attained with 1,1-disubstitued dienophiles, though the 1,2-disubstituted ones afforded poorer results. In contrast, (S)-[2-(p-tolylsulfinyl)phenyl] vinyl ketones 9–11 reacted readily at low temperature (?40 °C) with complete endo selectivity and high facial selectivity in the presence of Yb(OTf)₃ as a chelating reagent of sulfinyl and carbonyl oxygen atoms. Concerning furan reactions, β-trifluoromethyl enone 14 afforded Diels–Alder adducts with high facial selectivity in the presence of the Lewis acid, but β-non-substituted enones 9 and 12 yielded products of furan conjugate addition to the double bond.     

Synthesis and reactions of some new (E)-2-сyano-N′-[1-(pyren-3-yl)ethylidene]acetohydrazide derivatives

Russian Journal of General Chemistry - Some novel (E)-2-cyano-3-(substituted phenyl/dimethylamino)-N′-[1-(pyren-3-yl)]acrylohydrazides and benzochromenone-2-carbohydrazide derivatives were...     

Synthesis and hydrazinolysis of β-(1,3,4-oxadiazol-2-yl)pyridines

Cyclization of the hydrazide of 5-ethoxycarbonyl-2,6-dimethylpyridine-3-carboxylic acid by acylation with aromatic or aliphatic acid chlorides with subsequent boiling in POCl₃ or heating in orthoformic acid gave the corresponding ethyl 2,6-dimethyl-5-(5-R-1,3,4-oxadiazol-2-yl)pyridine-3-carboxylate. The cyclization of the reaction products with hydrazine hydrate has been studied. Cyclization of the dihydrazide of 2,6-dimethyl-3,5-pyridinedicarboxylic acid under analogous conditions gave only 3,5-bis-(5-R-1,3,4-oxadiazol-2-yl)-2,6-dimethylpyridines, containing R = 2-FC₆H₄, H.