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1.
The synthesis of atropisomeric 2-substituted benzamides 2a-e, 3a-e, and 4a-e, and characterization by X-ray structure analysis of 2d, 2e, 3c, 3e, 4c, and 4e are reported. Dynamic 1H NMR spectroscopic studies of benzamides 2b-d, 3b-d, and 4b-d indicate that only two of the four possible rotamers are present in solution, with population ratios ranging between 1.5:1 and 4.1:1. The measured free energy of activation to interconversion of the rotamers ranged from 12.4 to 18.9 kcal mol−1. Benzamides ArCON[(S)-phenethyl]2 (2e, 3e, and 4e), exhibited atropisomer ratios between 1.7:1 and 1:1, and free energies of interconversion of the rotamers ranged from 11.5 to 17.6 kcal mol−1. The highest rotation barriers were observed for the ortho-nitro derivatives 2a-e. Molecular calculations at the semiempirical level (PM3MM) gave free energies of activation for benzamides 2e and 3e of 23.6 and 12.4 kcal mol−1, respectively, which are comparable to the experimental values.  相似文献   

2.
Four new coordination complexes with azole heterocycle ligands bearing acetic acid groups, [Co(L1)2]n (1), [CuL1N3]n (2), [Cu(L2)2·0.5C2H5OH·H2O]n (3) and [Co(L2)2]n (4) (here, HL1=1H-imidazole-1-yl-acetic acid, HL2=1H-benzimidazole-1-yl-acetic acid) have been synthesized and structurally characterized. Single-crystal structure analysis shows that 3 and 4 are 2D complexes with 44-sql topologies, while another 2D complex 1 has a (43)2(46)-kgd topology. And 2 is a 3D complex composed dinuclear μ1,1-bridging azido CuII entities with distorted rutile topology. The magnetic properties of 1 and 2 have been studied.  相似文献   

3.
Novel condensation reaction of tropone with N-substituted and N,N′-disubstitued barbituric acids in Ac2O afforded 5-(cyclohepta-2′,4′,6′-trienylidene)pyrimidine-2(1H),4(3H),6(5H)-trione derivatives (8a-f) in moderate to good yields. The 13C NMR spectral study of 8a-f revealed that the contribution of zwitterionic resonance structures is less important as compared with that of 8,8-dicyanoheptafulvene. The rotational barriers (ΔG) around the exocyclic double bond of mono-substituted derivatives 8a-c were obtained to be 14.51-15.03 kcal mol−1 by the variable temperature 1H NMR measurements. The electrochemical properties of 8a-f were also studied by CV measurement. Upon treatment with DDQ, 8a-c underwent oxidative cyclization to give two products, 7 and 9-substituted cyclohepta[b]pyrimido[5,4-d]furan-8(7H),10(9H)-dionylium tetrafluoroborates (11a-c·BF4 and 12a-c·BF4) in various ratios, while that of disubstituted derivatives 8d-f afforded 7,9-disubstituted cyclohepta[b]pyrimido[5,4-d]furan-8(7H),10(9H)-dionylium tetrafluoroborate (11d-f·BF4) in good yields. Similarly, preparation of known 5-(1′-oxocycloheptatrien-2′-yl)-pyrimidine-2(1H),4(3H),6(5H)-trione derivatives (14a-d) and novel derivatives 14e,f was carried out. Treatment of 14a-c with aq. HBF4/Ac2O afforded two kinds of novel products 11a-c·BF4 and 12a,c·BF4 in various ratios, respectively, while that of 14d-f afforded 11d-f. The product ratios of 11a-c·BF4 and 12a-c·BF4 observed in two kinds of cyclization reactions were rationalized on the basis of MO calculations of model compounds 20a and 21a. The spectroscopic and electrochemical properties of 11a-f·BF4 and 12a-c·BF4 were studied, and structural characterization of 11c·BF4 based on the X-ray crystal analysis and MO calculation was also performed.  相似文献   

4.
The reaction of salicylaldehyde (1), o-aminophenols (2a-2f), and di-n-butyltinIV oxide (3) to give six di-n-butyltinIV compounds (4a-4f) was achieved in good yields. All compounds were characterized by 1H, 13C, 15N, 119Sn NMR, mass spectrometry, IR, elemental analysis and in the case of compounds 4a, 4b, 4d and 4e by X-ray diffraction analysis. Compound 4a crystallized with trigonal bipiramidal (TPB) geometry surrounding the tin atom while 4b and 4e crystallized as dimeric molecules joined by two O?Sn bonds with distorted octahedron (DOC) geometry. The X-ray structure of 4d presents one cocrystallized monomeric TBP with one dimeric DOC molecule. Correlations of σHammett vs. spectroscopic values were found for 4a-4b and 4d-4f, indicating the substituents in the aromatic ring derived from o-aminophenol serve as modulators of the O?Sn supramolecular interaction. The O?Sn bond formation is selective for the five-membered ring oxygen atom.  相似文献   

5.
Two binuclear complexes [CpM(Cl)CarbS]2 (Cp = η5-C5Me5, M = Rh (1a), CarbS = SC2(H)B10H10, Ir (1b)) were synthesized by the reaction of LiCarbS with the dimeric metal complexes [CpMCl(μ-Cl)]2 (M = Rh, Ir). Four mononuclear complexes CpM(Cl)(L)CarbS (L = BunPPh2, M = Rh (2a), Ir (2b); L = PPh3, M = Rh (4a), Ir (4b)) were synthesized by reactions of 1a or 1b with L (L = BunPPh2 (2); PPh3 (4)) in moderate yields, respectively. Complexes 3a, 3b, 5a, 5b were obtained by treatment of 2a, 2b, 4a, 4b with AgPF6 in high yields, respectively. All of these compounds were fully characterized by IR, NMR, and elemental analysis, and the crystal structures of 1a, 1b, 2a, 2b, 4a, 4b were also confirmed by X-ray crystallography. Their structures showed 3a, 3b and 5a, 5b could be expected as good candidates for heterolytic dihydrogen activation. Preliminary experiments on the dihydrogen activation driven by these half-sandwich Rh, Ir complexes were done under mild conditions.  相似文献   

6.
The preparation and characterization of the ammonium hexafluorosilicate salts, 2[R]+ [SiF6]2− (where R=piperidinium (2), methylammonium (3), quinolinium (4), acridinium (5), 2,2,6,6-tetramethylpiperidinium (6), and propylammonium (7)) is described.The salts were prepared from the reaction of the corresponding alkylammonium fluoride with silica gel. The compounds were characterized by NMR, IR, mass spectrometry and in the case of 1 (piperidinium fluoride), 2-4 by X-ray crystallography. Compounds 1-3 crystallize in the orthorhombic crystal system (space groups Iba2, Fdd2, and Pnnm, respectively), with Z=8, 14, and 4, respectively. Compound 4 crystallizes in the triclinic space group P-1, with Z=2. Compounds 1-4 exhibit hydrogen bonding.  相似文献   

7.
The reactions of hexachlorocyclotriphosphazene, N3P3Cl6, with mono (1 and 2) and bis(4-fluorobenzyl) diamines (3-5), FPhCH2NH(CH2)nNHR (RH or FPhCH2-), produce mono (1a and 2a) and bis(4-fluorobenzyl) monospirocyclophosphazenes (3a-5a). The tetraaminomonospirocyclophosphazenes (1b-2d) are obtained from the reactions of the partly substituted phosphazenes (1a and 2a) with excess pyrrolidine, morpholine and 1,4-dioxa-8-azaspiro[4,5]decane (DASD), respectively. The tetrachlorobis(4-fluorobenzyl) monospirocyclophosphazenes (4a and 5a) with excess pyrrolidine, morpholine and DASD afford the fully substituted bis(4-fluorobenzyl) monospirocyclophosphazenes (4b, 4d-5d) in boiling THF. In addition, monochlorobis(4-fluorobenzyl) monospirocyclophosphazenes (4e and 4f) have also been isolated from the reactions with excess morpholine and DASD in boiling THF. The structural investigations of the compounds have been verified by elemental analyses, MS, FTIR, 1H, 13C, 19F (for 1d and 2d), 31P NMR, HSQC and HMBC techniques. The crystal structures of 3a, 4a, 5a and 2b have been determined by X-ray crystallography. The compounds 2a-5a, 1b-2d, 4b, 4d-5d, 4e and 4f have been screened for antibacterial effects on bacteria and for antifungal activity against yeast strains. The compounds 1b and 4b showed antimicrobial activity against three species of bacteria, Bacillus subtilis, Bacillus cereus and Staphylococcus aureus, and two fungi, Candida albicans and Candida tropicalis. Minimum inhibitory concentrations (MIC) were determined for 1b and 4b. The MIC values were found to be 5000 μM for each bacteria. The most effective compound, 4b has exhibited activity with a MIC of 312 μM for C. albicans and 625 μM for C. tropicalis. DNA-binding and the nature of the interaction with pBR322 plasmid DNA are studied. All of the compounds induce changes on the DNA mobility and intensity. Prevention of HindIII digestion with the compounds indicates that the compounds bind with AT nucleotides in DNA.  相似文献   

8.
Aryldiazepinothiophenones 4 were prepared from the reaction of o-phenylenediamines with acetone in the presence of 2-mercaptocarboxylic acids along with thiazolobenzodiazepines 6, thiazolobenzimidazoles 7 and 1,5-benzodiazepines 5, which were obtained as by-products. The benzodiazepinothiophenones 4a-d and the benzodiazepines 5a-d were also isolated from the reaction of o-phenylenediamines 1a-c with phorone. Structural assignments of the new compounds as well as complete assignment of 1H and 13C NMR signals were based on the analysis of their 1H and 13C NMR (1D and 2D), IR, MS and elemental analysis data. Compounds 4 were evaluated for aldose reductase inhibition and also as antioxidants.  相似文献   

9.
10.
Six organotin compounds with 4,4′-thiodibenzenethiol (LH2) of the type RnSnL4−nSnRn (n = 3: R = Me 1, Ph 2, PhCH23, n = 2: R = Me 4, Ph 5, PhCH26) have been synthesized. All compounds were characterized by elemental analysis, IR and NMR (1H, 13C, and 119Sn) spectra. The structures of compounds 1, 2, 4, 5 and 6 were also determined by X-ray diffraction analysis, which revealed that compounds 1 and 2 were monomeric structures, compounds 4, 5 and 6 were centrosymmetric dinuclear macrocyclic structures, and all the tin(IV) atoms are four-coordinated. Furthermore, supramolecular structures were also found in compounds 1, 2, 4, 5 and 6, which exhibit one-dimensional chains, two-dimensional networks or three-dimensional structures through intermolecular C–H?S weak hydrogen bonds (WHBs), non-bonded Sn?S interactions or C–H?π interactions.  相似文献   

11.
Through ring-closure reactions of N- or 1′-substituted 1-(2′-aminoethyl)-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolines (5a-e) with phenylphosphonyl dichloride, 1- or 3-substituted 4-phenyl-1,3,4,6,7,11b-tetrahydro-2H-1,3,2-diazaphosphorino[6,1-a]isoquinolin-4-one diastereomers (7a-e and 8a-c,e), the first representatives of a new ring system, were prepared. The diastereomeric ratios in the cyclizations and the conformer (A-E) populations of the nitrogen-bridged tricyclic systems (7 and 8) were strongly influenced by the N- and 1′-substituents of the starting diamines. The conformational analysis of compounds 7 and 8 was performed by 1H, 13C and 31P NMR methods.  相似文献   

12.
Photoinduced cycloadditions of N-methyl-1,8-naphthalenedicarboximide 1 with phenylacetylenes 2a-2c, cyclopropylacetylene 2d, diphenylacetylenes 2e-2f and 1-phenylpropyne 2g were investigated. In the case of phenylacetylenes 2a, 2b and cyclopropylacetylene 2c, photoreaction with 1 takes place at the naphthalene C(1)C(2) bond to give the cyclobutene products. For 4-methoxyphenylacetylene 1c, the cyclobutene 3c is obtained together with the 4-benzo[a]thebenidinone 4c derived from a primary oxetene product formed by [2+2] addition of the imide carbonyl with the alkyne. Similar to 2c, photocycloaddition of 1 with 2e and 2f gave the cyclobutenes 7e, 7f, 8f and the 4-benzo[a]thebenidinone products 9e, 9f and 10f, respectively, derived from the corresponding oxetenes. Photoreaction of 1 with 2g gave cyclobutene 7g and benzo[a]thebenidinone 9g. Sensitization experiment and internal heavy atom effect study showed that these reactions proceed from the ππ* singlet excited state of 1. Estimation of the free energy change for electron transfer between 11* and the alkynes and the calculation of charge and spin density distribution in the anion radical of 1 and the cation radical of the alkynes suggested that the cyclobutene products are formed by direct [2+2] cycloaddition of 11* with the alkyne, while the formation of the oxetene products is the result of electron transfer interaction between 11* and the alkyne. The regioselectivity in the oxetene formation is accounted for by charge and spin density distribution in the anion radical of 1 and the cation radical of the alkyne.  相似文献   

13.
Two new N-pyrazole, P-phosphinite hybrid ligands 3-(3,5-dimethyl-1H-pyrazol-1-yl)propyldiphenylphosphinite (L3) and 2-(3,5-diphenyl-1H-pyrazol-1-yl)ethyldiphenylphosphinite (L4) are presented. The reactivity of these ligands and two other ligands reported in the literature (3,5-dimethyl-1H-pyrazol-1-yl)methyldiphenylphosphinite (L1) and 2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyldiphenylphosphinite (L2) towards [RhCl(CO)2]2 (1) have been studied and complexes [RhCl(CO)L] (L = L2 (2), L3 (3) and L4 (4)) have been obtained. For L1 only decomposition products have been achieved. All complexes were fully characterised by analytical and spectroscopic methods and the resolution of the crystalline structure of complexes 2 and 3 by single-crystal X-ray diffraction are also presented. In these complexes, the ligands are coordinated via κ2(N,P) to Rh(I), forming metallocycles of seven (2 and 4) or eight (3) members and finish its coordination with a carbonyl monoxide and a trans-chlorine to phosphorus atom. In both complexes, weak intermolecular interactions are present. NMR studies of complexes 2-4 show the chain N-(CH2)x-O becomes rigid and the protons diastereotopic.  相似文献   

14.
The cothermolysis of benzoyl(tert-butyl)bis(trimethylsilyl)silane with 2,3-dimethylbutadiene in a sealed tube at 140 °C for 24 h afforded cis- and trans-1-tert-butyl-4,5-dimethyl-2-phenyl-2-(trimethylsiloxy)-1-(trimethylsilyl)-1-silacyclohex-4-ene (2 and 3) in a ratio of approximately 1:1 in 66% combined yield. When cis-silacyclohex-4-ene 2 was heated in a sealed tube at 250 °C for 24 h, dyotropic ring contraction took place to give 1-[(tert-butyl)(trimethylsiloxy)(trimethylsilyl)silyl]-3,4-dimethyl-1-phenylcyclopent-3-ene (4), but not trans-2-tert-butyl-4,5-dimethyl-2-phenyl-1-(trimethylsiloxy)-1-(trimethylsilyl)-1-silacyclohex-4-ene (6). The thermolysis of trans-silacyclohex-4-ene 3 under the same conditions, however, afforded two products, 1-silyl-1-phenylcyclopent-3-ene 4 and trans-1-tert-butyl-4,5-dimethyl-2-phenyl-1-(trimethylsiloxy)-2-(trimethylsilyl)-1-silacyclohex-4-ene (5). The theoretical calculations were carried out to characterize the transition states and other local minima, and to evaluate the activation energies for the dyotropic rearrangement of 2 to 4 and 6, and 3 to 4 and 5. The energy barriers between 2 and 4, between 3 and 4, and between 3 and 5 were evaluated to be 188, 191, 192 kJ mol−1, respectively. The energy barrier between 2 and 6, however, was calculated to be 201 kJ mol−1 or higher. These results are consistent with the experimental finding that the thermal isomerization of 2 affords only 4, but 3 produces both 4 and 5.  相似文献   

15.
Cyclocondensation of 1-aryl-3-ferrocenyl-2-propen-1-ones (1) with hetaryl hydrazines resulted in N-hetaryl-3-aryl-5-ferrocenyl pyrazolines (3, 4). The analogous 3-aryl-1-ferrocenyl-2-propen-1-ones (5) gave the isomeric N-hetaryl-5-aryl-3-ferrocenyl-pyrazolines (6, 10), but in lower yield. The reaction of aryl-chalcones (7) with 4-hydrazino-phthalazinone led to 3,5-bis-aryl-N-hetaryl-pyrazolines (8) or to the corresponding ene-hydrazones (9). The structure of the new compounds was established by IR, 1H and 13C NMR spectroscopy, including DNOE, HMQC, HMBC and DEPT methods. For compounds 1b, 3b and 8b the stereo structure was elucidated also by X-ray diffraction.  相似文献   

16.
Syntheses of rac/meso-{PhP(3-t-Bu-C5H3)2}Zr{Me3SiN(CH2)3NSiMe3} (rac-3/meso-3) and rac/meso-{PhP(3-t-Bu-C5H3)2}Zr{PhN(CH2)3NPh} (rac-4/meso-4) were achieved by metallation of K2[PhP(3-t-Bu-C5H3)2] · 1.3 THF (2) with Zr{RN(CH2)3NR}Cl2(THF)2 (where R = SiMe3 or Ph, respectively) using ethereal solvent. These isomeric pairs were characterized by 1H, 13C{1H}, and 31P{1H} NMR spectroscopy; rac-3 and rac-4 were also examined via single crystal X-ray crystallography. The structures of rac-3 and rac-4 are notable in the tendency of the cyclopentadienyl rings towards η3 coordination. While isolated samples of rac-3/meso-3 and rac-4/meso-4 slowly isomerize in tetrahydrofuran-d8 to equilibrium ratios, the isomerization rate for 3 is more than 15-fold greater than that for 4. In addition, equilibrium ratios are rapidly reached when isolated samples of rac-3/meso-3 and rac-4/meso-4 are exposed to tetrabutylammonium chloride in tetrahydrofuran-d8 solvent. We propose that a nucleophile (either chloride or the phosphine interannular linker) brings about dissociation of one cyclopentadienyl ring, thus promoting the rac/meso isomerization mechanism.  相似文献   

17.
The syntheses and structures of a series of metal complexes, namely Cu2Cl4(L1)(DMSO)2·2DMSO (L1 = N,N′-bis(2-pyridinyl)-1,4-benzenedicarboxamide), 1; {[Cu(L2)1.5(DMF)2][ClO4]2·3DMF} (L2 = N,N′-bis(3-pyridinyl)-1,4-benzenedicarboxamide), 2; {[Cd(NO3)2(L3)]·2DMF} (L3 = N,N′-bis-(2-pyrimidinyl)-1,4-benzenedicarboxamide), 3; {[HgBr2(L3)]·H2O}, 4, and {[Na(L3)2][Hg2X5]·2DMF} (X = Br, 5; I, 6) are reported. All the complexes have been characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. Complex 1 is dinuclear and the molecules are interlinked through S?S interactions. In 2, the Cu(II) ions are linked through the L2 ligands to form 1-D ladder-like chains with 60-membered metallocycles, whereas complexes 3 and 4 form 1-D zigzag chains. In complexes 5 and 6, the Na(I) ions are linked by the L3 ligands to form 2-D layer structures in which the [Hg2X5] anions are in the cavities. The L2 ligand acts only as a bridging ligand, while L1 and L3 show both chelating and bridging bonding modes. The L1 ligand in 1 adopts a trans-anti conformation and the L2 ligand in 2 adopts both the cis-syn and trans-anti conformations, whereas the L3 ligands in 36 adopt the trans conformation.  相似文献   

18.
Copper complexes [Cu(Ln)2] 1-4 bearing N,O-chelating β-ketoamine ligands Ln based on condensation products of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone with aniline (L1), α-naphthylamine (L2), o-methylaniline (L3), and p-nitroaniline (L4), respectively, were synthesized and characterized by IR, 1H NMR and X-ray crystallography (except 2). They were shown to catalyze the vinyl polymerization of norbornene when activated by methylaluminoxane (MAO). Both steric and electronic effects are important and influential factors contributing to the catalytic activity of the complexes with the order of 2 > 4 > 3 > 1.  相似文献   

19.
A series of organotin(IV) complexes with 2,5-dimercapto-1, 3, 4-thiodiazole (HHdmt) of the type (RnSnClm)2(dmt) (m=0, n=3, R=Ph 1, PhCH22, n-Bu 3; m=1, n=2, R=Ph 4) and [R2Sn(dmt) · L]n (L=0.5C6H6, R=CH35; L=0, n=5, R=n-Bu 6) have been synthesized. All complexes 1-6 were characterized by elemental analysis, IR, 1H and 13C NMR spectra. And except for 3, complexes 1, 2, 4, 5 and 6 were also determined by X-ray crystallography. The tin atoms of complexes 1, 2, 3 and 4 are all five-coordinated. The geometries at tin atoms of 1, 2, 3 and 4 are distorted trigonal bipyramidal. The tin atoms of complexes 5 and 6 are six-coordinated and their geometries are distorted octahedral.  相似文献   

20.
The synthesis of [(E)-arylimino]-acetonitriles 3 has been described. It was found that the title compounds can be obtained on the three ways, namely by: (i) dehydrogenation of arylaminoacetonitriles 1, (ii) thermal fragmentation of 1-aryl-4-cyano-β-lactams 4 and (iii) retro-ene reaction of (allyl-p-methoxyphenyl-amino)-acetonitrile (7a) under FVT conditions. 1H and 13C NMR spectra of compounds 3, 5 and 6, and all their precursors 1 and 4, were recorded and analysed in detail using chemical shifts δH and δC [from GIAO DFT B3LYP/6-31(d) calculations] and J-couplings predicted at the DFT B3LYP/IGLO-II level. Also, UV-photoelectron spectra of 4a,d and 3a,d were measured and analysed considering the theoretical evaluation of their ionisation potentials.  相似文献   

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