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1.
The 13C NMR spectra of [1.2]-spirenes 2 and spiro[2.4]hepta-(4.6)-dienes 5 are described and the effects of substituents are discussed. A bonding model of the [1.2]-spirenes 2 is derived on the basis of C-H coupling constants and calculated charge densities. The 13C NMR shifts of 1-aryl-spiro[2.4]hepta-(4.6)-dienes 6 show a good correlation with the Hammett σp constants of the substituents in p-position of the phenyl ring. Conclusions on spiroconjugation in [1.2]-spirenes 2 are drawn from comparing the 13C shifts of similar substituted [1.2]-spirenes and spiro[2.4]hepta-(4.6)-dienes. The spiroconjugation in [1.2]-, [2.2]- and [2.3]-spirenes 2, 3 and 4 is discussed comparing the calculated charge densities with the δ (13C) values, as well as the UV and p.e. spectra.  相似文献   

2.
《Tetrahedron: Asymmetry》2000,11(5):1109-1122
A mixture of cis- and trans-2-(6-m-methoxyphenyl-3-oxohexyl)-2,4-dimethylcyclopenta-1,3-dione (±)-10 was synthesized and incubated with Schizosaccharomyces pombe (NRRL Y-164) to give (+)-11, (+)-12, (−)-13, and (−)-14 in 19, 13, 22, and 16% yields, respectively. Chromic acid oxidation of these microbiologically reduced products gave (−)-10a, (+)-10b, (+)-10a, and (−)-10b, respectively.  相似文献   

3.
The self-assembly of unsymmetrical tecton 3-nitro-5-(pyridin-4-yl)benzoic acid (HL)with cobalt chloride under hydrothermal conditions affords a new 2D coordination polymer [Co(L)2] n (1, L = 3-nitro-5-(pyridin-4-yl)benzoate), which is characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, powder X-ray diffraction analysis, and single crystal X-ray diffraction. Compound 1 is of the triclinic system, space group P-1 with a = 9.7857(12) Å, b = 10.3417(13) Å, c = 10.8463(13) Å, α = 85.155(2)°, β = 74.785(2)°, γ = 88.962(2)°, V = 1055.4(2) Å3. The crystal structural analysis of complex 1 shows that the cobalt center is six-coordinated in an octahedral geometry by four O atoms from four different L ligands and two N atoms from two different L ligands; the Co(II) cations are bridged by μ3-L into an interesting two-dimensional network structure. It should be pointed out that the thermal analysis results indicate that complex 1 is quite stable up to 420°C.  相似文献   

4.
The Grignard reagents R3Si(CC)nMgBr (R = Me, n = 1; R = Et, n = 1,2) couple with cyclooctatetraene dibromide 1 in THF to give, as major products, the silyl-stabilised E, Z, Z, E-polyeneynes, Me3SiCC(CHCH)4CCSiMe33a, Et3SiCC(CHCH)4CCSiEt34a and Et3Si(CC)2(CHCH)4(CC)2SiEt36a together with minor proportions of configurational isomers Z, E, Z, Z 3c, all -E 3b, 4b, 6b and compounds in which a bicyclo-octadiene structure 2, 5 and 7 is retained. Irradiation converts the cis(Z)-rich isomers e.g. 3c into the all-trans(E) products. Treatment of the bissilyl compounds 3, 4 and 6 with aqueous base liberates the respective parent polyeneynes, H(CC)n(CHCH)4(CC)nH, in each case.  相似文献   

5.
The Wittig olefination of ferrocene-containing chalcones leads to 1,3-dienes and their cyclodimers. The reaction of 1,3-dienes with dibromocarbene yields gem-dibromo(ferrocenylvinyl)cyclopropanes. Upon reductive dehalogenation with ethylmagnesium bromide they afford the corresponding monobromo derivatives. All the obtained compounds were characterized by 1H and 13C NMR, elemental analysis, and mass spectrometry. The structures of compounds 5a,b, 6g, 6h, and 7i were confirmed by X-ray diffraction analysis.  相似文献   

6.
Tetrakis(1H-pyrazol-1-yl)methanes are very rare compounds of which only two are known: the unsubstituted 1 obtained classically by Hückel in 1937 from carbon tetrachloride and prepared again several times and the 3,5-dimethyl substituted 2 obtained serendipitously by Pombeiro in 2009. We have now extended this group to include four new derivatives 8, 9, 11 and 12 bearing methyl groups. The X-ray crystal structure of the four compounds has been determined. They have been studied by NMR both in solution (1H, 13C, 15N) and in the solid state (13C and 15N). DFT calculations of the six compounds (geometries, energies and absolute shieldings) have been used to discuss the experimental observations.  相似文献   

7.
The reaction of (SPY-5-34)-dichloro-(κ2(C,O)-2-formylbenzylidene)(H2IMes)ruthenium (H2IMes=1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene) with potassium hydridotris(pyrazolyl)borate (KTp) in dichloromethane yielded an unusual ruthenium complex chloro(κ3(N,N,N)-chlorotris(pyrazolyl)borate)(κ2(C,C)-1-(2,4,6-trimethylphenyl)-3-(4,6-dimethylphenyl-2-methylidene)-4,5-dihydroimidazol-2-ylidene)ruthenium (2). In 2, a chlorotris(pyrazolyl)borate ligand, which had been created during this reaction, binds in κ3(N,N,N)-mode to the central ruthenium atom. Additionally, a double C–H activation of a methyl group of the H2IMes resulted in the formation of a chelating N-heterocyclic biscarbene ligand and liberation of the former 2-formylbenzylidene as 2-methylbenzaldehyde. Formally, a double hydrogen transfer from a methyl group of the H2IMes to the initial carbene carbon occurred. 2 was characterized by NMR spectroscopy, elemental analysis and single crystal X-ray structure determination. The reaction of KTp with (SPY-5-34)-dichloro(κ2(C,O)-2-ethoxycarbonylbenzylidene)(H2IMes)ruthenium, on the other hand, gave the expected product chloro(κ3(N,N,N)-hydridotris(pyrazolyl)borate)(H2IMes)(2-ethoxycarbonylbenzylidene)ruthenium (6). Compound 6 was characterized by NMR spectroscopy, elemental analysis and single crystal X-ray structure determination. Investigations of the relative activities of these complexes in model ring opening metathesis polymerizations showed a pronounced thermal latency. Polymerizations proceeded at temperatures above 100 °C in case of 6 and 130 °C in case of 2.  相似文献   

8.
Seven new indole alkaloids including a new indoloazepinone derivative (2), two new quinazolinone derivatives (7, 8) and four new pyrazinoquinazolinone derivatives: epi-fiscalin C (10), epi-fiscalin A (12), neofiscalin A (13), epi-neofiscalin A (14) were isolated, together with 4-dihydroxy-3-methylacetophenone (1), tryptoquivaline (3), tryptoquivalines L (4), H (5), F (6) as well as fiscalins A (11) and C (9), from the culture of the fungus Neosartorya siamensis (KUFC 6349). The absolute configuration of the stereogenic carbons of the previously reported tryptoquivalines F, H, L was revised using the data obtained from an X-ray analysis of tryptoquivaline l and the NOESY correlations. The structures of the new pyrazinoquinazolinone derivatives (10, 12, 13, 14) were established based on 1D and 2D NMR spectral analysis, and the absolute configuration of their stereogenic carbons was determined by an X-ray crystallographic analysis of fiscalin C (9) and a new compound epi-fiscalin C (10), in conjunction with the correlations observed in their NOESY and long range COSY spectra. Compounds 28 and 12 were evaluated for their in vitro growth inhibitory activity on the human U373 and Hs683 glioblastoma, the A549 non-small cell lung cancer, the MCF-7 breast cancer and the SKMEL-28 melanoma cell lines by MTT colorimetric assay.  相似文献   

9.
The compounds [o-C6-H4CH2E]2Sn-W(CO)5, (E = NMe2 (1) or PPh2 (2)) have been prepared by reaction of o-LiC6H4CH2E with pentacarbonyltungsten tin(II) chloride (CO)5WSnCl2. The complexes were characterized by 13C, 31P, and 119Sn NMR spectroscopy and by X-ray diffraction analyses. 1 crystallizes monoclinically in the space group C/c (no. 15) with a 1310.2(4), b 1552.1(4), c 1202.9(4) pm, β 90.11(4)°, and Z = 4. 2 crystallizes monoclinically in the space goup P21/n (no. 14) with a 2108.1(4), b 1707.7(4), c 1283.7(3) pm, β 97.47(2)° and Z = 4. The structures were refined to final R values of 0.029 and 0.039, respectively.The SnW bond distances of 274.9 and 276.2 pm are very similar in both complexes. The Sn atoms are penta-coordinated by 2C, 2N and W in 1 and by 2C, 2P and W in 2. The penta-coordination comprises one SnW and two SnC single bonds, and either a SnN (in 1) or a SnP bond (in 2) of bond order 0.45. In the stannyl group of 1 the SnN bond distances both are identical by symmetry (256.4 pm), whereas the two SnP bond lengths of 2 differ to some extent (283.1 and 301.2 pm).  相似文献   

10.
《Tetrahedron: Asymmetry》2007,18(14):1701-1711
Both enantiomers (8aR)-7 and (8aS)-7 of bicyclofarnesol were synthesized from the enzymatic resolution products (1R,4aR,8aR)-1,2,3,4,4a,5,6,7,8,8a-decahydro-5,5,8a-trimethyl-2-oxo-trans-naphthalene-1-methanol-2-ethylene acetal (8aR)-5 (98% ee) and acetate of (1S,4aS,8aS)-1,2,3,4,4a,5,6,7,8,8a-decahydro-5,5,8a-trimethyl-2-oxo-trans-naphthalene-1-methanol-2-ethylene acetal (8aS)-6 (>99% ee), respectively. The formal synthesis of (+)-wiedendiol 1 was achieved via a coupling reaction of an ate complex derived from 1,2,4-trimethoxybenzene with allyl bromide (8aS)-8 derived from (8aS)-7. The total synthesis of (+)-norsesterterpene diene ester 2 was achieved, based on the synthesis of (13E,10S)-α,β-unsaturated aldehyde 12, derived from (8aS)-7, followed by the selective construction of the (3E,5E)-diene moiety including a C(2)-stereogenic centre in (+)-2. The total synthesis of (−)-subersic acid 3 was carried out based on a Stille coupling between allyl trifluoroacetate congener 25c, derived from (8aR)-7, corresponding to the diterpene part, and aryl stannane congener 26 in the presence of Pd catalyst and CuI as an additive.  相似文献   

11.
The diiron ynamine complex [Fe2(CO)7{μ-CR)C(NEt2)}] (1:R=Me,2:R = C3H5.3:R=SiMe3.4:R = Ph) reacts at room temperature with diphenyldiazomethane Ph2CN2, in hexane to yield complexes [Fe2(CO)6{C(R)C(NEt2)N (NCPh2)] (5a:R=Me,6a:R=C3H5.7a R=SiMe3.8a:R=Ph) resulting from the insertion of the terminal nitrogen atom into the Fe=C carbene bond. Insertion the second nitrogen atom and formation of compounds [Fe2(CO)6zμ-C(R)C(NEt2)NN(CPh2)}] (5b:R=Me,6b:R=C3H5,7b:R=SiMe3,8b:R=Ph) is observed when compounds5a-5a are treated in refluxing hexane. Transformation of compoundsa tob is also obtained at room temperature within a few days. All compounds were identified by their1H NMR spectra. Compounds6a, 7a, 8a, and8b were characterized by single crystal X-ray diffraction analyses. Crystal data: for6a: space group = P21/n,a=12.853(1) A,b=24.800(7) A,c=8.947(6) A,β=99.29(3)°,Z=4, 2227 rellectionsR=0,038; for7a: space group=Pl,a=ll.483(4) A,b=14.975(4) A,c = 17.890(8) A,α = 82.80(3)°,β=94.29(7)°,γ=85.42(2),Z = 4, 5888 reflectionR = 0.035: for8a: space group = Pcab.a = 31.023(8) A.b=20.137(1) A.c=9.686(2) A.Z=8. 1651 reflections,R=0.071; for8b: space group=P21/n,a=21.459(4),b=10,100(3) A,c=28,439(8) A,ß=103.86(4)°,Z=8. 2431 reflections.R=0.057.  相似文献   

12.
Synthesis, structural characterization, and biological activity studies of o-carborane-substituted 1,3,5-triazines (9-12) containing polar functional groups such as methoxyethyl and t-butoxycarbonylmethyl amine units are described. De-methylation of di(methoxyethyl)amine functionalized triazines 9 and 10 resulted in the production of di(hydroxyethyl)amine derivatives 13 and 14. NMR (1H and 13C) and X-ray crystallographic studies confirmed the structures derived from the sequential o-carborane substitution on the 1,3,5-triazine core. Preliminary in vitro studies revealed that compounds 9, 10, 13, and 14, despite their low cytotoxicity, accumulated at high levels in B-16 melanoma cells.  相似文献   

13.
《Polyhedron》2001,20(7-8):695-702
Three Co(III) complexes of the type [Co(salophen)(amine)2]ClO4, salophen=N,N′-disalicylidene-1,2-phenylendiamine dianion and amine=morpholine (1), pyrrolidine (2), and piperidine (3), have been synthesized and characterized by elemental analysis, IR, UV–Vis, 1H, and 13C NMR spectroscopy. [Co(salophen)(morpholine)2]ClO4 (1) and [Co(salophen)(pyrrolidine)2]ClO4 (2) have been studied by X-ray diffraction. Compound 1 crystallizes in ribbons of complexes and perchlorates held together by weak NH⋯O and CH⋯O hydrogen bonds between morpholines and perchlorates. The latter also interconnect the chains to a 3D network. Some minor π–π interactions exist. Compound 2 crystallizes as endless chains of complexes linked by weak CH⋯O hydrogen bonds to the disordered perchlorates. The pyrrolidine moiety is turned by 90° with respect to 1 and forms intramolecular NH⋯O hydrogen bonds. The coordination polyhedra of 1 and 2 possess Cs symmetry, and the salophens are not planar in either of them.  相似文献   

14.
Synthesis of chalcogen (S and Se) derivatives of 4-chloro- and 4-methoxy-N,N-diisopropylpyridine-2-carboxamide (1a and 1b respectively) has been reported. 1a and 1b were lithiated with 2 equiv. of n-BuLi or LDA at ?78 °C. Addition of elemental sulfur or selenium to the carbanion led to the formation of corresponding thiolate or selenolate anions respectively. The selenolate anions were aerial oxidized to afford the corresponding diselenides. The thiolate/selenolate anions were quenched with a variety of electrophiles to give unsymmetrical thio/selenoalkanes in moderate to good yields. Reductive cleavage of Se–Se bond has also been studied. The synthesized compounds were characterized by elemental analysis, NMR (1H, 13C and 77Se), FT-IR and mass spectral techniques. Crystal structures of two compounds, 6b and 7a, were determined by single crystal X-ray crystallography. Their crystal structure exhibits 1,4-type S?OCH3 and Se?Cl intramolecular secondary interactions respectively. The relative thermal stability of 3a, 3b and 4a has also been established by thermogravimetric analysis.  相似文献   

15.
Wittig reaction of (E)-3-(3-guaiazulenyl)propenal (11) with (3-guaiazulenylmethyl)triphenylphosphonium bromide (9) in ethanol containing NaOEt at 25 °C for 24 h under argon gives the title new (2E,4E)-1,3-butadiene derivative 4, in 33% isolated yield, which upon treatment with hexafluorophosphoric acid (i.e., 65% HPF6 aqueous solution) in tetrahydrofuran (=THF) at 25 °C for 1 h under aerobic conditions affords a new air (two-electron) oxidation product (E)-ethylene-1,2-bis(3-guaiazulenylmethylium) bis(hexafluorophosphate) (14), quantitatively, and further, zinc-reduction of 14 in trifluoroacetic acid (=CF3COOH) at 0 °C for 1 h under argon reverts 4, quantitatively. Along with the above interesting results, our discovered another preparation method, spectroscopic properties, crystal structure, and electrochemical behavior of 4, which serves as a strong two-electron donor and acceptor, compared with those of the previously reported (E)-1,2-di(3-guaiazulenyl)ethylene (3) are documented in detail.  相似文献   

16.
The (alkynylcarbyne)tungsten complexes [L3(CO)2WCCCR] (3a,b6a,b) [L3=hydro[tris(3,5-dimethylpyrazol-1-yl)]borato (Tp′, 3), hydro[tris(pyrazol-1-yl)]borato (Tp, 4), cyclopentadienyl (Cp, 5), bis(3,5-dimethylpyrazol-1-yl)acetato (bdmpza, 6); R=SiMe3 (a), Ph (b)] were prepared in a stepwise fashion from [W(CO)6] and Li[CCR], (CF3CO)2O and M[L3] (M=Na, K). The formation of 6a,b was highly selective, only complexes with a trans arrangement of the carboxylate group of bdmpza and the alkynylcarbyne ligand were detected. The reaction of [W(CO)6] with Li[CCR], C2O2Cl2 and tmeda afforded trans-[Cl(CO)2(tmeda)WCCCR] (7a,b). The electron-donating potential of the different tripodal ligands L3 was studied by IR- and 13C-NMR spectroscopy and compared to that of the ligand combination Cl/tmeda. The IR data suggest that in these complexes bdmpza is a weaker electron donor than Tp′ and Tp but displays stronger electron-donating abilities than Cp. The structures of 6b and 7b were established by X-ray structural analyses.  相似文献   

17.
Three Cd(II) or Co(II) macroacyclic Schiff-base complexes [CoL1Br]ClO4 (1), [CdL2Cl]ClO4 (2) and [CdL3(NO3)]ClO4 (3) were prepared by template condensation of 2-pyridinecarboxaldehyde and three different amines containing piperazine moiety, N,N′-bis(2-aminoethyl)piperazine, N,N′(2-aminoethyl)(3-aminopropyl)piperazine and N,N′-bis(3-aminopropyl)piperazine, in the presence of Co(II) or Cd(II) metal ions, respectively. All complexes have been studied with IR, FAB mass and microanalysis and for complex (3) by 1H and 13C NMR spectra. One of these complexes, [CdL3(NO3)]ClO4 (3) has been characterized through X-ray crystallography. In complex (3), the Cd(II) ion is coordinated by the six nitrogen donor atoms from the ligand and by one oxygen atom from a monodentate nitrate ion in a N6O environment.  相似文献   

18.
Shaoman Zhou  Jiri Zemlicka 《Tetrahedron》2007,63(38):9406-9412
Synthesis of methylene-2-ethynylcyclopropane analogues of nucleosides 12a, 12b, 13a, and 13b is described. Ethyl methylenecyclopropane carboxylate 14 was hydroxymethylated to give alcohol 15, which was reduced to diol 16. Selective protection with tert-butyldimethylsilyl group gave derivative 17, which was oxidized to aldehyde 18. Wittig reaction with CBr4 gave dibromoalkene 19. Elimination of both bromine atoms afforded methylene-2-ethynylcyclopropane 20. Bromoselenenylation using N-bromosuccinimide and diphenyldiselenide gave intermediate 21. Alkylation of adenine and 2-amino-6-chloropurine with 21 provided the Z,E-isomeric mixtures 22a and 22c. Oxidation afforded selenoxides 23a and 23c. Mild thermolysis furnished methylenecyclopropanes Z-24a, E-24a, and 24c. Deprotection and separation of Z,E-isomers gave adenine analogues 12a and 13a, and 2-amino-6-chloropurine intermediates 12c and 13c. Hydrolytic dechlorination of 12c and 13c afforded guanine analogues 12b and 13b. Adenine Z-isomer 12a inhibits replication of Epstein-Barr virus through its cytotoxicity. The E-isomer 13a is a substrate for adenosine deaminase.  相似文献   

19.
Palladium(II) complexes containing di-(2-pyridyl)-N-methylimine (1), di-(2-pyridyl)methanol (2) and di-(2-pyridyl)methyl-N,N-diethyldithiocarbamate (4) ligands were synthesized and characterized by 1H and 13C NMR in solution, IR and X-ray single crystal diffraction. Crystal structures of cis-dichloro[di-(2-pyridyl)-N-methylimine]palladium(II) (5), cis-dichloro[di-(2-pyridyl)methanol]palladium(II) (6) and cis-dichloro[di-(2-pyridyl)methyl-N,N-diethyldithiocarbamate]palladium(II) (7) showed a bidentate coordination mode of the di-(2-pyridyl)methane derivatives 1, 2 and 4. In these complexes is observed the formation of a five-membered chelate ring with the iminic ligand 1 and six-membered chelate rings with the pyridinic ligands 2 and 4. In all complexes the palladium atom displays a distorted square planar geometry.  相似文献   

20.
A new series of di- and tri-organotin(IV) compounds with the general formula R4?n SnL n , where R?=?Me (1,2), Et (3), n-Bu (4,5), n-Oct (6), Ph (7) and L?=?(E)-3-(4-methoxyphenyl)-2-(4-chlorophenyl)-2-propenoate, were synthesized by reaction of silver salt of ligand or ligand acid with diorganotin dichloride/oxide and triorganotin chloride in 2:1 and 1:1 molar ratio, respectively. These compounds were characterized by elemental analyses, FT-IR, multinuclear (1H, 13C, 119Sn) NMR and mass spectrometry. The spectroscopic results revealed that all the diorganotin(IV) compounds possess trigonal bipyramidal structures in solution and octahedral geometry in the solid state around the tin atom. A linear polymeric trigonal bipyramidal structure in the solid state and a tetrahedral environment around the tin atom in non-coordinating solvents has been proposed for the triorganotin(IV) compounds. All synthesized compounds were tested in vitro against a number of microorganisms to assess their biocidal activity. These studies revealed that ligand acid and some of its organotin compounds show promising activity against different strains of bacteria and fungi but lowered than reference drugs.  相似文献   

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