Formation of 2-substituted benzofuran fragment ions from 6-alkyl- and 6-aryldibenzo(d,f)(1,3)dioxepine derivatives under electron ionization-a useful precursor ion for isomeric differentiation

Tandem mass spectrometry has been applied to differentiate three sets of o-, m- and p-methyl, -methoxy and -nitro-substituted-6-phenyl-dibenzo(d,f)(1,3)dioxepines. Collision-induced dissociation (CID) experiments have been carried out on 2-phenylbenzo[b]furan fragment ions, which originate from the decomposition of the molecular ions after their EI-induced isomerization to spirocyclic structures. With the exception of m- and p-methylphenylbenzo[b]furan isomers, which display identical CID mass spectra, the three isomeric methoxy- and nitrophenylbenzo[b]furan fragment ions display very characteristic CID behavior which allows unequivocal differentiation of the 6-phenyl-dibenzo(d,f)(1,3)dioxepine isomers. 6-(o-nitrophenyl)-dibenzo(d,f)(1,3)dioxepine isomer, does not form a 2-(o-nitrophenyl)benzo[b]furan ion and, therefore, it can be differentiated from the m- and p- isomers based on the mere EI mass spectra. Furthermore, it shows a characteristic ion most likely due to an ortho effect between the nitro group and the dioxepine ring. Multiple stage mass spectrometric techniques (MSn), labeled derivatives and reference compounds were used in order to gain additional information on the structures of product ion from the CID fragmentation.     

Electron ionization-induced fragmentation of N-(alkoxymethyl)anilides

Electron ionization-induced fragmentation patterns of the series of N-(alkoxymethyl)acetanilides and related formanilides and benzanilides have been studied. The main fragmentation reaction observed for all compounds studied is the loss of an alkyl radical from the N-alkoxymethyl group leading to the appropriate protonated N-acylformanilide derivatives. This reaction is accompanied by unusually high kinetic energy release. Other important fragmentations common for majority of the compounds studied are (i) loss of an aldehyde molecule derived from an alkoxyl group yielding an appropriate N-acyl-N-methylaniline, (ii) elimination of a C(n)H(2n)O(2) fragment derived from N-alkoxymethyl group and carbonyl group oxygen atom and (iii) formation of N-methyleneaniline radical cation.     

Synthesis, Crystal Structure, Physical Properties, and Application of a Series of Functional Dibenzo[d,f][1,3]dioxepine Derivatives

The twisted aromatics, functional dibenzo[d,f][1,3]dioxepine derivatives were synthesized in high yields from reactions of 5,5＇-dibromo-2,2＇-biphenol with corresponding ketal or ketone compounds under acid catalysis. The structures of these compounds were characterized by ^1H NMR, elemental analysis, UV-Vis absorption spectrum and X-ray diffraction analysis. The conformation of O--C--O bridged biphenyl derivatives with varied substitute groups on 6,6＇-position was studied by X-ray crystallography and force-field simulation. The result of calculations by UNIVERSAL 1.02 force field in Cerius2 package（4.6） indicates that dibenzo[d,f][1,3]dioxepine derivatives show twisted conformations and the twisted angle between the phenyl rings is about 40°, which is accordant with the result from crystal structure determination, though the obtained angles in the crystal of dibenzo[d,f][1,3]dioxepine derivatives with the varied substitute groups on 6,6＇-position are shown to be slightly shifted to 40° owing to intermolecular interactions in crystal stacking. DSC studies exhibit that the substitute groups on 6,6＇-position can induce a large variation of endothermic peaks ranging from 80 to 135 ℃. The conjugated polymers based on dibenzo[d,f][1,3]dioxepine derivatives, which have ultraviolet emitting with a quantum efficiency of 10%, were obtained by Yamamoto coupling.     

区域选择性合成二苯并[d,f][1,3]二噁烷

针对二苯并[d,f][1,3]二噁烷传统制备方法中易产生二羟基联苯乙烯副产物的缺点,本文以路易斯酸性胍盐离子液体为催化剂,2,2'-二羟基联苯和端基炔为原料,高区域选择性的合成了二苯并[d,f][1,3]二噁烷,收率39%~84%。 本方法适用于各种端基炔。路易斯酸性胍盐离子液体循环利用5次,活性不变。     

Indium(III) chloride catalyzed one step synthesis of some new dibenzo(d,f)(1,3)dioxepines and 12H-dibenzo(d,g)(1,3)dioxocin derivatives

In the presence of catalytic amount of indium(III) chloride (10 mol %), 2,2′-dihydroxybiphenyl and bis(2-hydroxyphenyl)methane react quickly, without using any solvent, with ketones or β-keto esters possessing at least one hydrogen atom in α to the ketone-carbonyl group, to afford some new dibenzo(d,f)(1,3)dioxepines and some 12H-dibenzo(d,g)(1,3)dioxocin derivatives, respectively.     

Preparation of 4-trifluoroethylidene-1,3-dioxolane derivatives via new stable (trifluoromethyl)ethynylation reagent

Perfluoroalkylated 4-trifluoroethylidene-1,3-dioxolane derivatives 2a-q were prepared in excellent yields from the reaction of new stable (trifluoromethyl)ethynylation reagent 1a with 1.3 equiv. of TBAF at −15°C for 10 min, followed by treatment with 2 equiv. of phenyl perfluoroalkylated ketone derivatives at room temperature. The reaction of 1a with 1.3 equiv. of TBAF, followed by treatment with 1 equiv. of aldehyde or ketone at −15°C for 10 min and then with trifluoroacetophenone (1 equiv.) at room temperature afforded perfluoroalkylated 4-trifluoroethylidene-1,3-dioxolane derivatives 2t-u in moderate yields.     

Synthesis of Alkyl 6-(2-Alkoxy-2-oxoethyl)dibenzo[d,f][1,3]dioxepine-6-carboxylates from Stabilized Phosphorus Ylides

Protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and dialkyl acetylenedicarboxylates, by biphenyl-2,2′ -diol leads to vinyltriphenylphosphonium salts, which undergo a Michael addition reaction with a conjugate base to produce the corresponding stabilized phosphorus ylides. Magnesium oxide powder was found to catalyze the conversion of the stabilized phosphorus ylides to alkyl 6-(2-alkoxy-2-oxoethyl)dibenzo[d,f][1,3]dioxepine-6-carboxylates in solvent-free conditions under microwave (0.5 KW, 3 min) and thermal (90 °C, 60 min) conditions.     

Conformational Behavior of Rigid and Dancing (1,3)(1,4)Cyclophanes

Annelation or substitution of the (1,4)-bridged ring of [2₂](1,3)(1,4)cyclophane 4 , such as in 8 and 9 , respectively, result in two different conformational ground states in each case. Each conformational ground state involves a different destabilizing factor arising from one form of non-bonding interaction. Only the conformers 8b and 9b were isolated experimentally. Their corresponding precursors 11 and 23 were also found to be conformationally rigid. Only the conformers 11a and 23a were isolated indicating an abrupt change in conformational preference going from the dithia[3₂]cyclophanes to the respective [2₂]cyclophanes. The selectively methylated [2₂]cyclophanes 27 , 31 and 32 were, however, found to be conformationally mobile. There is an increase of about 10–15 kJ mol^?1 in conformational energy barrier going from 4 to 27 or 31 . This is consistent with the fact that the presence of the methyl substituents increases the relative conformational ground-state energy more than it would affect the transition-state energy. The conformational barrier of 32 was unexpectedly found to be similar to those of 27 and 31 . This could be explained by a decrease in the transition-state energy due to an inward bending of the (1,4)-bridged ring accompanied by a decrease in conformational ground-state energy due to an outward bending of the methyl groups in 32 .     

Reactions of cyclic 1,3-dicarbonyl compounds with 1,2(1,4)-dihydro-1-methyl-2(4)-methylene-N-heterocycles. A new access to 6,12-methano-dibenz[d,g]-[1,3]oxazocinones

Summary The enamine-type methylene-N-heterocycles1–5 react with cyclic 2-ethoxymethylene-1,3-dicarbonyl compounds6 to give 2-[2-(hetarylidene)ethylidene]-1,3-dicarbonyl compounds7–14. The result of the reactions between 1,2-dihydro-1-methyl-2-methylene-quinoline (1a) and cyclic 1,3-dicarbonyl compounds depends on the nature of the dihydro intermediatesA/B. Dehydrogenation of keton intermediatesA results in 2-(1,2-dimethyl-4(1H)-quinolylidene)-1,3-dicarbonyl compounds17–21. Enol intermediatesB with 6-membered dicarbonyl ring form 6,12-methano-dibenz-[d,g][1,3]oxazocinones22–25.¹H NMR spectra and X-ray structure analysis prove the structure of23.

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Reaktionen cyclischer 1,3-Dicarbonylverbindungen mit 1,2(1,4)-Dihydro-1-methyl-2(4)-methylen-N-heterocyclen. Ein neuer Zugang zu 6,12-Methano- dibenz[d,g][1,3]oxazocinonen

Zusammenfassung Aufgrund ihres Enamincharakters reagieren die Methylen-N-heterocyclen1–5 mit cyclischen 2-Ethoxymethylen-1,3-dicarbonylverbindungen6 zu den 2-[2-(Hetaryliden)ethyliden]-1,3-dicarbonylverbindungen7–14. Das Ergebnis der Reaktionen zwischen 1,2-Dihydro-1-methyl-2-methylen-chinolin (1a) und cyclischen 1,3-Dicarbonylverbindungen hängt von der Natur der zwischenzeitlich entstehenden DihydroverbindungenA/B ab. Die Intermediat-KetoneA gehen durch Dehydrierung während der Reaktion in die 2-(1,2-Dimethyl-4(1H)chinolyliden)-1,3-dicarbonylverbindungen17–21 über. Die Intermediat-EnoleB mit sechsgliedrigem Dicarbonylring bilden in intramolekularer Reaktion die 6,12-Methano-dibenz[d,g][1,3]oxazocinone22–25, deren Struktur am Beispiel der Verbindung23 durch¹H-NMR sowie durch Röntgenkristallstrukturanalyse bewiesen wird.

     

Electron ionization-induced fragmentation of R2N2Fe2(CO)6 complexes with distinct geometries of the tetrahedral core: investigation of mu-1,2-(1,2-diaza-3-methylcyclopentane)diylbis(tricarbonyliron) and bis(mu2-acetophenoniminato)bis(tricarbonyliron)

Two binuclear bis(tricarbonyliron) title complexes with N(2)Fe(2) tetrahedral cores, 1 and 2, respectively, which show different molecular folding resulting from the appearance (in 1), and absence (in 2) of the N-N sigma-bond, were compared in terms of mass spectral fragmentation routes. A multipath fragmentation noted for the molecule 1 revealing internal stress contrasts with the single-route fragmentation of 2. The fragmentation paths resulting from the admixtures were defined and analyzed from the fragment ion B/E and parent ion B(2)/E linked scan spectra.     

1H and 13C NMR assignments for new heterocyclic TAM leuco dyes, (2Z,2'E)-2,2'-(2-phenyl propane-1,3-diylidene) bis(1,3,3-trimethylindoline) derivatives. Part II

The (1)H and (13)C NMR spectra of the novel heterocyclic Leuco-TAM dyes, (2Z, 2'E)-2,2'-(2-phenyl propane-1,3-diylidene) bis(1,3,3-trimethylindoline) derivatives 1-4 as precursors of triarylmethane (TAM)(+) (Malachite Green FB-analog) dyes were completely assigned by 1D and 2D NMR experiments, including DEPT, COSY, HSQC, HMBC, and NOESY. Especially, the diastereotopic gem-dimethyl protons at the C3 and C3' positions of the FB rings were definitively assigned. The (Z,E) isomers adopt the energetically favored three-bladed propeller conformation in solution.     

Utilization of cyanoacetohydrazide and 2-(1,3-dioxoisoindolin-2-yl) acetyl chloride in the synthesis of some novel anti-proliferative heterocyclic compounds

Abstract

Owing to its high reactivity and commercial availability, 2-cyanoacetohydrazide can be utilized as a versatile and appropriate intermediate for synthesis of a broad variety of heterocyclic compounds. Thus, 2-cyanoacetohydrazide and 2-(1,3-dioxoisoindolin-2-yl) acetyl chloride were used as starting materials for construction of new heterocyclic compounds bearing 1,3-dioxoisoindoline moiety. The newly synthesized compounds were recognized by elemental analyses and spectral data (IR, ¹H-NMR, and ¹³C-NMR spectra). The synthesized compounds were screened for their anti-proliferative activity against two human epithelial cell lines; breast (MCF-7) and liver (HepG2) as well as to normal fibroblasts (WI-38). The data showed distinctly that compounds 1 and 12 presented promising in-vitro anti-proliferative activity against two cell lines (MCF-7 and HepG2) without harming normal fibroblasts.     

Synthesis and characterization of mercury(II) complexes with 2-styryl-1,3-benzothiazole (sb). Presence of two differently coordinated Hg(II) ions in the dinuclear complex Hg2Cl4(sb)3. Structural characterization of 2-styryl-1,3-benzothiazole and some of its derivatives

The molecular and crystal structures of the following compounds 2-styryl-1,3-benzothiazole, sb, (1), Hg₂Cl₄(sb)₃ (2), 1,3-bis(1,3-benzothiazol-2-yl)-2,4-diphenylcyclobutane (3) 1,3-bis(1,3-benzothiazol-2-yl)-2,4-bis(4-chlorophenyl)cyclobutane (4) and HgBr₂(sb)₂ (5) were determined by single-crystal X-ray diffractometry. The crystal structure of 1 consists of discrete sb molecules which are essentially planar. The dimeric molecules of 3 and 4 are characterized by a cyclobutane ring. In both isolated complexes 2 and 5, sb acts as a neutral monodentate ligand coordinated to the mercury atom through the thiazolyl nitrogen atom. The dinuclear complex 2 is characterized by the unique example of two differently coordinated Hg(II) ions bridged via a non-symmetrical linear Cl⁻ bridge. The first one is coordinated by one terminal and one bridging Cl⁻ ion and two thiazolyl nitrogen atoms in the form of distorted tetrahedron. The second one is bonded to two terminal Cl⁻ ions and the bridging Cl⁻ ion and one thiazolyl nitrogen atom in a 2+2 manner. In complex 5 the Hg(II) ion, which is situated on a crystallographic twofold axis, is tetrahedrally coordinated by two Br⁻ ions and two thiazolyl nitrogen atoms. Both complexes are characterized by stronger mercury-to-halide covalent bonds than mercury-to-nitrogen bonds, which are regarded as contacts shorter than the van der Waals radii sum of the corresponding atoms. The geometry of the sb ligand in both complexes 2 and 5 has not been changed remarkably from that one in the uncoordinated state due to not so strong bonds formation with the Hg(II) ion.     

Synthesis,characterization and antimicrobial activity of triorganotin(IV) derivatives of some bioactive Schiff base ligands

Triorganotin(IV) complexes of the type Me₃Sn[OC(R¹):CH(CH₃)C:NR²OH] and Ph₃Sn[OC(R′):CH(CH₃)C:NR″OH] (R′ = ─CH₃, ─C₆H₅; R″ = ─(CH₂)₂─, ─(CH₂)₃─) have been synthesized by the reactions of trimethyl/phenyltin(IV) chloride with the sodium salt of corresponding Schiff base ligands in unimolar ratio in refluxing tetrahydrofuran. All these compounds have been characterized using elemental analyses and their probable structures have been proposed on the basis of infrared, ¹H NMR, ¹³C NMR, ¹¹⁹Sn NMR and mass spectroscopic studies. In the trimethyltin(IV) derivatives the central tin atom is tetracoordinated, whereas in the analogous triphenyltin(IV)derivatives the central tin atom is pentacoordinated. All these ligands, metal precursors and corresponding triorganotin(IV) complexes have been screened for antimicrobial activities. A comparison of activities of the ligands and their corresponding triorganotin(IV) derivatives has been made. Attempts have also been made to relate the activity to the structure of these compounds.     

Four (2,2′‐bipyridyl)(ferrocenyl)boronium derivatives

Crystal structures are reported for four (2,2′‐bipyridyl)(ferrocenyl)boronium derivatives, namely (2,2′‐bipyridyl)(ethenyl)(ferrocenyl)boronium hexafluoridophosphate, [Fe(C₅H₅)(C₁₇H₁₅BN₂)]PF₆, (Ib), (2,2′‐bipyridyl)(tert‐butylamino)(ferrocenyl)boronium bromide, [Fe(C₅H₅)(C₁₉H₂₂BN₃)]Br, (IIa), (2,2′‐bipyridyl)(ferrocenyl)(4‐methoxyphenylamino)boronium hexafluoridophosphate acetonitrile hemisolvate, [Fe(C₅H₅)(C₂₂H₂₀BN₃O)]PF₆·0.5CH₃CN, (IIIb), and 1,1′‐bis[(2,2′‐bipyridyl)(cyanomethyl)boronium]ferrocene bis(hexafluoridophosphate), [Fe(C₁₇H₁₄BN₃)₂](PF₆)₂, (IVb). The asymmetric unit of (IIIb) contains two independent cations with very similar conformations. The B atom has a distorted tetrahedral coordination in all four structures. The cyclopentadienyl rings of (Ib), (IIa) and (IIIb) are approximately eclipsed, while a bisecting conformation is found for (IVb). The N—H groups of (IIa) and (IIIb) are shielded by the ferrocenyl and tert‐butyl or phenyl groups and are therefore not involved in hydrogen bonding. The B—N(amine) bond lengths are shortened by delocalization of π‐electrons. In the cations with an amine substituent at boron, the B—N(bipyridyl) bonds are 0.035 (3) Å longer than in the cations with a methylene C atom bonded to boron. A similar lengthening of the B—N(bipyridyl) bonds is found in a survey of related cations with an oxy group attached to the B atom.     

Brönsted酸性离子液体催化芳香醛和2-甲基喹啉反应合成1,3-二(2-喹啉基)丙烷化合物

以Brönsted酸性离子液体1-乙基-3-丁基咪唑对甲苯磺酸盐为催化剂, 将芳香醛和2-甲基喹啉类化合物在无溶剂或甲苯中于120 ℃反应48 h, 制备了一系列的1,3-二(2-喹啉基)丙烷化合物, 产率56%~92%, 产物结构经核磁共振波谱和高分辨质谱确证. 该方法具有简便易行、 产率较高等特点.     

d(C4)相关序列形成四分子i-Motif结构的电喷雾质谱研究

设计了与富含胞嘧啶(C)的DNA序列d(C4)相关的DNA序列d(C4), d(TC4), d(AC4), d(T2C4), d(A2C4), d(C4T), d(C4A)和d(TC4T); 采用电喷雾质谱测定发现这些序列形成四分子非共价复合物离子, 根据离子的相对丰度可确定形成四链i-motif结构的数量和可能性; 同时考察了腺嘌呤(A)和胸腺嘧啶(T)在d(C4)序列的5'和3'端对其形成四分子i-motif结构的影响. 结果表明, 在d(C4)的5'端增加A碱基或T碱基更易形成四分子复合物; 5'端含T碱基比含A碱基更利于形成四分子复合物; 而在d(C4)序列中增加2个A碱基或T碱基比增加相应的单个碱基形成了更高丰度的四分子离子峰.     

Synthesis and Crystal Structure of N-[(3aR,4R,4aR,5aS,6S,6aS)-1,3-Dioxooctahydro-4,6-ethenocyclopropa[f]lisoindol-2(1H)-yl]-3-(trifluoromethyl)phenylmethanimine

The crystal structure of the title compound (C19H15F3N2O2, Mr= 360.33) was determined by single-crystal X-ray diffraction. The crystal belongs to triclinic, space group P(1), with a = 6.5604(7), b = 13.9614(16), c = 18.1790(18) (A), α = 102.749(7),β = 97.542(6), γ = 94.355(4)°, V= 1600.5(3) (A)3, Z = 4, Dc = 1.495 g/cm3, λ(MoKα) = 0.71070, F(000) = 744, μ(MoKα) = 0.122mm-1, R = 0.0434 and wR = 0.1051. A total of 7590 unique reflections were collected, of which 5429 with |F|2 ≥ 2σ|F|2 were observed. The two cyclohexene rings in the molecule adopt boat-boat conformations with the deviations of ring atoms C(9) and C10 from the C(5)/C(6)/C(7)/C(8) plane (Ⅰ) by 1.1204 (0.0023) and 1.1132 (0.0023) (A), respectively, whereas from the C(2)/C(3)/C(5)/C(8)plane (Ⅱ) by 1.1627 (0.0022) and 1.1818 (0.0021) (A), respectively. In the cyclopropane and lactam rings, atoms C(11) and N(1) point towards the double bond of C(9)-C(10) and the dihedral angle between the ring plane (Ⅲ) containing C(1), C(2), C(3) and C(4) and plane (Ⅳ) consisting of C(6),C(7) and C(11) is 55.76 (0.07)°. The dihedral angles between planes Ⅳ and Ⅰ and Ⅱ and Ⅲ are 63.58 (0.07)° and 58.10 (0.06)°, respectively. The dihedral angle between the benzene ring C(13)～C(18) and plane Ⅳ is 42.41 (0.06)°.     

Hydrothermal Synthesis,Structure, and Magnetic Properties of a Three‐dimensional Polymeric NiII Complex, [Ni(bpp)(NIP)(H2O)]n (bpp = 1,3‐di(4‐pyridyl)propane,NIP = 5‐nitroisophthalate)

A three‐dimensional polymeric Ni^II complex, [Ni(bpp)(NIP)(H₂O)]_n (bpp = 1,3‐di(4‐pyridyl)propane and NIP = 5‐nitroisophthalate), has been synthesized and characterized. The coordination number of the nickel atom is six (NiN₂O₄) and the coordination environment around the Ni^II atom may be described as a distorted octahedron in which two nitrogen atoms of “bpp” ligand occupy the cis positions. The effective magnetic moment for this complex indicate that the interactions between two Ni^II atoms through the effective exchange media are antiferromagnetic. Self‐assembly of these compounds in the solid state via π–π‐stacking interactions is discussed.