We report on the synthesis and electronic spectra of the chiral, donor‐acceptor (push‐pull) chromophores (±)‐ 4 and (±)‐ 5 with a 6H,12H‐5,11‐methanodibenzo[b,f][1,5]diazocine scaffold (Scheme 1 and Fig. 2). The electronic structures of these compounds were investigated at a quantum‐chemical level (Figs. 2 and 3). The chemical reactivity of 6H,12H‐5,11‐methanodibenzo[b,f][1,5]diazocine ((±)‐ 11 ) towards aromatic electrophilic substitution (Scheme 2 and Table) provided additional information about its electronic structure and confirmed nonnegligible delocalization of the lone pair of the bridge‐head N‐atoms in this heterocyclic system. 相似文献
Preparation of 4‐chloro‐3H‐benzo[b][1,4]diazepine‐2‐carbaldehyde 5 , which is used as a key intermediate in the synthesis of chalcones derivatives, via its condensation with some aromatic acetophenone derivatives under ethanol piperidine condition was described. Also illustrated was the reaction of such chalcones with available nucleophilics and reagents of active methylene group to afford new series of fused and isolated pyrazoles, isoxazolines pyrimidines, pyridines, triazolo[1,5‐a]pyrimidines, benzo[1,4]oxa(thia)zepines, and pyrido[1,2‐a]benzimidazoles incorporating 4‐chloro‐3H‐benzo[b][1,4]diazepine moiety, which have a potential pharmaceutical interest. Furthermore, condensation reaction of 4‐chloro‐3H‐benzo[b][1,4]diazepine‐2‐carbaldehyde with aromatic amine derivatives to afford the Schiff's bases was described. The C═N double bond of the latter compounds has been reacted with chloroketene to give β‐lactams and with sulfanylacetic acid to give the 2‐(4‐oxo‐1,3‐thiazolidinyl)‐substituted derivative. The structures of the newly prepared compounds were established by elemental analysis, IR, MS, and 1H NMR spectral analysis. 相似文献
We announce the establishment of a new family of macrocycles—the asararenes, which are based on para‐methylene linked “asarol methyl ether” (1,2,4,5‐tetramethoxybenzene) units. Macrocycles with 6–12 aromatic units have been synthesized and isolated in a single step from asarol methyl ether and paraformaldehyde. Even larger rings, with up to 15 asarol methyl ether units, have been observed by high‐resolution mass spectrometry. Single‐crystal X‐ray structures of asar[6]‐, asar[7]‐, asar[8]‐, asar[9]‐, asar[10]‐ and asar[11]arene highlight the diverse structural features of this family of macrocycles. While the cavities of the asar[6–8]arene macrocycles are mostly filled with methoxyl groups, the asar[9]‐ and asar[10]arene rings contain accessible cavities and self‐assemble into infinite channels filled with solvent molecules in the solid state. These solid‐state structures highlight the potential of this family of macrocycles for a wide range of potential applications. 相似文献
Metal‐organic frameworks were achieved from triple metal helical iron complex [(Fe2L3)·(H2O)4] (L = bis[2‐hydroxybenzaldehyde]hydrazonate). The phenyl rings of the helical units contact the neighbors via π‐π and C‐H···π interactions to form two‐dimensional channeled frameworks in which four solvent water molecules are included in the channels of the structure. Thermogravimetric analyses reveal that the solvent water molecules can be evacuated from the pores without loss of the framework periodicity. The crystal lattice is thermally stable up to 339.9 °C, and water can be re‐included by putting the heated material in water. 相似文献
Enantio‐ and stereoselective cyclopolymerization of hexa‐1,5‐diene was achieved by enantiomerically pure dichloro zirconium(IV) pre‐catalysts 2 possessing chiral [OSSO]‐type bis(phenolate) ligands (−)‐ 1 and (+)‐ 1 in combination with dried methylaluminoxane (dMAO) as an activator. The corresponding activities were recorded with quite high values up to 1,960 g mmol( 2 )–1 h–1, which are extremely larger than those of the related complexes. The microstructure analysis for the PMCPs furnished by pre‐catalysts (Λ,S,S)‐ 2 and (Δ,R,R)‐ 2 showed good isotacticity factors (α = 75−78%) and relatively high proportions of trans‐cyclopentane rings (σ = 14−21%). These enantiomeric PMCPs exhibited large specific optical rotations ([α]D = +28 to +32° from (Λ,S,S)‐ 2 , −26 to −34° from (Δ,R,R)‐ 2 ).
The compound 2[Ca(H2O)3 (DMF@CB[6])] · 2(BTC) · 15H2O ( CCUT ‐ 102 , CB[6] = cucurbit[6]uril; H3BTC = 1,3,5‐benzenetricarboxylic acid) was synthesized using the approach of organic guest‐induced formation of polymers or frameworks based on the coordination of metal ions and cucurbit[n]urils. The compound was characterized by X‐ray diffraction analysis, PXRD, IR spectroscopy, thermogravimetric and elemental analyses. According to the X‐ray diffraction data, the calcium atom is coordinated by the oxygen atoms of the CB[6] molecule, water molecules, and N ,N‐dimethylformamide (DMF). The internal cavity of CB[6] is occupied by DMF. Each H3BTC molecule interacts the CB[6] molecules through π?π interactions between aromatic rings of H3BTC and the rings of CB[6]. The luminescence behaviors and sensing properties of CCUT ‐ 102 in different solvents were also studied. 相似文献
5‐Amino‐3‐methyl‐4‐phenylazo‐1H ‐pyrazole and ethyl cyanoacetate reacted in solvent‐free media at 150°C to produce 7‐amino‐3‐phenylazo‐2‐methyl‐4H ‐pyrazolo[1,5‐a]pyrimidine‐5‐one ( 3 ). A series of aromatic amines was coupled using this compound ( 3 ) and nitrous acid to produce new pyrazolo[1,5‐a] pyrimidine derivatives with two arylazo groups 4(a‐m) . The structures of these dyes were determined via UV–vis, Fourier transform infrared, proton nuclear magnetic resonance, high‐resolution mass spectral data, and elemental analysis. After synthesis, the solvent and acid–base effects of the dyes were investigated within the UV–vis region. The antimicrobial properties of the dyes were also studied. All dyes exhibited activity against Gram‐positive and Gram‐negative bacteria, and even against fungi. The results were compared to conventional reference results from the antibiotics ciprofloxacin and ketoconazole. Antioxidant potentials were analyzed using in vitro antioxidant models on the basis of DPPH (1,1‐d iphenyl‐2‐picrylhydrazyl) radical scavenging activities. Most of the compounds exhibited excellent antioxidant activities. In particular, compound 4b had a higher activity than Vitamin C. 相似文献
The 4‐chloro‐ [C14H11ClN2O2, (I)], 4‐bromo‐ [C14H10BrN2O2, (II)] and 4‐diethylamino‐ [C18H21N3O2, (III)] derivatives of benzylidene‐4‐hydroxybenzohydrazide, all crystallize in the same space group (P21/c), (I) and (II) also being isomorphous. In all three compounds, the conformation about the C=N bond is E. The molecules of (I) and (II) are relatively planar, with dihedral angles between the two benzene rings of 5.75 (12) and 9.81 (17)°, respectively. In (III), however, the same angle is 77.27 (9)°. In the crystal structures of (I) and (II), two‐dimensional slab‐like networks extending in the a and c directions are formed via N—H...O and O—H...O hydrogen bonds. The molecules stack head‐to‐tail viaπ–π interactions involving the aromatic rings [centroid–centroid distance = 3.7622 (14) Å in (I) and 3.8021 (19) Å in (II)]. In (III), undulating two‐dimensional networks extending in the b and c directions are formed via N—H...O and O—H...O hydrogen bonds. The molecules stack head‐to‐head viaπ–π interactions involving inversion‐related benzene rings [centroid–centroid distances = 3.6977 (12) and 3.8368 (11) Å]. 相似文献
The intramolecular [2+2] photocycloaddition of four 4‐(but‐3‐enyl)oxyquinolones (substitution pattern at the terminal alkene carbon atom: CH2, Z‐CHEt, E‐CHEt, CMe2) and two 3‐(but‐3‐enyl)oxyquinolones (substitution pattern: CH2, CMe2) was studied. Upon direct irradiation at λ=300 nm, the respective cyclobutane products were formed in high yields (83–95 %) and for symmetrically substituted substrates with complete diastereoselectivity. Substrates with a Z‐ or E‐substituted terminal double bond showed a stereoconvergent reaction course leading to mixtures of regio‐ and diastereomers with almost identical composition. The mechanistic course of the photocycloaddition was elucidated by transient absorption spectroscopy. A triplet intermediate was detected for the title compounds, which–in contrast to simple alkoxyquinolones such as 3‐butyloxyquinolone and 4‐methoxyquinolone–decayed rapidly (τ≈1 ns) through cyclization to a triplet 1,4‐diradical. The diradical can evolve through two reaction channels, one leading to the photoproduct and the other leading back to the starting material. When the photocycloaddition was performed in the presence of a chiral sensitizer (10 mol %) upon irradiation at λ=366 nm in trifluorotoluene as the solvent, moderate to high enantioselectivities were achieved. The two 3‐(but‐3‐enyl)oxyquinolones gave enantiomeric excesses (ees) of 60 and 64 % at ?25 °C, presumably because a significant racemic background reaction occurred. The 4‐substituted quinolones showed higher enantioselectivities (92–96 % ee at ?25 °C) and, for the terminally Z‐ and E‐substituted substrates, an improved regio‐ and diastereoselectivity. 相似文献
The synthesis of a novel benzimidazole derivative with a long‐chain‐ester substituent, namely methyl 8‐[4‐(1H‐benzimidazol‐2‐yl)phenoxy]octanoate, (3), is reported. Ester (3) shows evidence of aggregation in solution and weak gelation ability with toluene. The octan‐1‐ol solvate, methyl 8‐[4‐(1H‐benzimidazol‐2‐yl)phenoxy]octanoate octan‐1‐ol monosolvate, C22H26N2O3·C8H18O, (4), exhibits a four‐molecule hydrogen‐bonded motif in the solid state, with N—H…O hydrogen bonds between benzimidazole molecules and O—H…N hydrogen bonds between the octan‐1‐ol solvent molecules and the benzimidazole unit. The alkyl chains of the ester and the octan‐1‐ol molecules are in unfolded conformations. The phenylene ring is canted by 10.27 (6)° from the plane of the benzimidazole ring system. H…C contacts make up 20.7% of the Hirshfeld surface coverage. Weak C—H…π interactions involving the benzimidazole alkyl chain and three aromatic rings are observed. 相似文献
A three‐dimensional metal–organic framework (MOF), poly[[μ6‐5′‐pentahydrogen [1,1′‐biphenyl]‐3,3′,5,5′‐tetrayltetrakis(phosphonato)]erbium(III)] 2.5‐hydrate], formulated as [Er(C12H11O12P4)]·2.5H2O or [Er(H5btp)]·2.5H2O ( I ) and isotypical with a Y3+‐based MOF reported previously by our research group [Firmino et al. (2017b). Inorg. Chem. 56 , 1193–1208], was constructed based solely on Er3+ and on the polyphosphonic organic linker [1,1′‐biphenyl]‐3,3′,5,5′‐tetrakis(phosphonic acid) (H8btp). The present work describes our efforts to introduce lanthanide cations into the flexible network, demonstrating that, on the one hand, the compound can be obtained using three distinct experimental methods, i.e. hydro(solvo)thermal (Hy), microwave‐assisted (MW) and one‐pot (Op), and, on the other hand, that crystallite size can be approximately fine‐tuned according to the method employed. MOF I contains hexacoordinated Er3+ cations which are distributed in a zigzag inorganic chain running parallel to the [100] direction of the unit cell. The chains are, in turn, bridged by the anionic organic linker to form a three‐dimensional 6,6‐connected binodal network. This connectivity leads to the existence of one‐dimensional channels (also running parallel to the [100] direction) filled with disordered and partially occupied water molecules of crystalization which are engaged in O—H…O hydrogen‐bonding interactions with the [Er(H5btp)] framework. Additional weak π–π interactions [intercentroid distance = 3.957 (7) Å] exist between aromatic rings, which help to maintain the structural integrity of the network. 相似文献
In this communication, a simple and straightforward procedure for the heterocyclization of 1H‐4,5‐dihydro‐3‐(4‐haloaryl)‐5‐substituted phenylpyrazoles (4) with 1‐bromo‐3‐chloropropane and 2,3‐dibromo‐1‐(4‐fluoro‐3‐methylphenyl)‐3‐phe‐ nylpropanone affording 2,3,4,8,9‐pentahydro‐7‐(4‐haloaryl)pyrazolo[5,1‐e]benzo[1,5] oxazocines 5 and regioselective synthesis of 2,3(erythro),7,8‐tetrahydro‐2‐ aryl‐3‐(4‐fluoro‐3‐methylbenzoyl)‐6‐(4‐halophenyl)pyrazolo[5,1‐d]benzo[1,4]oxa‐ zepines 6, respectively, via solid–liquid PTC is reported. All the synthesized compounds have been characterized on the basis of their spectral studies (IR, PMR, and MS) and analytical data. 相似文献
The pure diolefinic ligand 1,4‐bis(pyridin‐4‐yl)‐1,3‐butadiene (bpbde) is photostable in the crystalline state. With the assistance of coordination‐driven metal‐organic assemblies, the photoreactivity of this diolefinic ligand can be significantly enhanced. A hydrothermal reaction of bpbde with Cd(NO3)2?4 H2O and the auxiliary ligand adipic acid resulted in the formation of a two‐dimensional photoreactive coordination polymer (CP), [Cd(adipate)(bpbde)]n ( 1 ). When the aliphatic carboxylic acid was replaced by pimelic acid, another photoreactive CP [Cd(pimelate)(bpbde)]n ( 2 ) with a three‐dimensional framework was obtained. With irradiation of 365 nm UV light, the bpbde ligands in crystalline 1 and 2 underwent a regioselective photochemical [2+2] cycloaddition reaction and converted to 3,4,7,8‐tetra(pyridin‐4‐yl)tricyclo[4.2.0.02,5]octane (tptco) and 1,3‐bis(pyridin‐4‐yl)‐2,4‐bis(2‐(pyridin‐4‐yl)vinyl)cyclobutane (bpbpvcb), respectively. The results provide an interesting insight into the rational design of highly regio‐ or stereoselective photocatalytic reactions for the formation of special organic molecules. 相似文献
In contrast with the reported phosphine‐ and DABCO‐catalyzed [3+2] and [2+2] annulation of allenoates with trifluoromethylketone, the [2+2+2] annulation of allenoates and two molecules of trifluoromethylketone was found under the condition of N‐heterocyclic carbene catalysis. 相似文献