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1.
《Magnetic resonance in chemistry : MRC》2003,41(7):554-556
The 13C NMR spectra of 22 piperidine‐, tropine‐ and tetradecahydroacridine‐derived saturated amine oxides were measured. The chemical shifts were assigned on the basis of APT and 2D‐INADEQUATE spectra, and are briefly discussed. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
2.
Potmischil F Marinescu M Nicolescu A Deleanu C Hillebrand M 《Magnetic resonance in chemistry : MRC》2008,46(12):1141-1147
The (15)N NMR chemical shifts of 1,2,3,4,5,6,7,8-octahydroacridine, 12 of its 9-substituted derivatives, and of the corresponding N-oxides were measured and examined in terms of the 9-substituent effects and the effects of N-oxidation. For the 9-substituent effects, good linear correlations were found with the Taft and Swain-Lupton substituent constants, for both octahydroacridines and their N-oxides. The (15)N chemical shifts of both octahydroacridines and their N-oxides also correlate well, linearly with the (13)C chemical shifts of the para-carbons in analogously substituted benzene derivatives.Within the studied compounds, the magnitudes of the N-oxidation effects range from - 16.4 to - 27.4 ppm (shielding), and also correlate linearly with the Taft and Swain-Lupton substituent constants, as well as with the bond orders of the N(+)-O(-) bonds in the corresponding N-oxides. Furthermore, a very good linear correlation is found between the (15)N chemical shifts of octahydroacridines and those of the corresponding N-oxides. From the (15)N chemical shifts data, the Taft and Swain-Lupton substituent constants for the diacetylamino group (-NAc(2)) were evaluated in the present paper, as follows: sigma(R) = 0.07 and sigma(I) = 0.15; R = 0.08 and F= 0.20. 相似文献
3.
《Magnetic resonance in chemistry : MRC》2002,40(3):237-240
The complete 1H NMR chemical shift assignments of 1,2,3,4,5,6,7,8‐octahydroacridine ( 1 ), 1,2,3,4,5,6,7,8‐octahydro‐9‐(3‐pyridyl)acridine ( 2 ), 1,2,3,4,5,6,7,8‐octahydro‐9‐(4‐pyridyl)acridine ( 3 ) and the corresponding N(10)‐oxides 1a , 2a and 3a , respectively, were achieved on the basis of 400 MHz 1H NMR spectra and proton–proton decoupling, HMQC and NOEDIFF experiments. The spectral data for the above compounds provided the first experimental evidence of the difference in the anisotropy effect of the two non‐symmetrical moieties of the pyridine nucleus, and allowed us to ascertain that the shielding effect of the moiety defined by the C(2′)—N—C(6′) atoms is weaker than that of the C(3′)—C(4′)—C(5′) moiety. The 13C NMR spectra of 1 – 3 and 1a – 3a and the effect of N(10)‐oxidation on the 13C NMR chemical shifts are also discussed. The N‐oxidation of 2 and 3 with m‐chloroperbenzoic acid occurred regiospecifically, affording the N(10)‐oxides 2a and 3a free of N(1′)‐oxide isomers. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
4.
Comparison of the substituent effects on the 13C NMR with the 1H NMR chemical shifts of CHN in substituted benzylideneanilines 下载免费PDF全文
Fifty‐two samples of substituted benzylideneanilines XPhCH?NPhYs (XBAYs) were synthesized, and their NMR spectra were determined in this paper. Together with the NMR data of other 77 samples of XBAYs quoted from literatures, the 1H NMR chemical shifts (δH(CH?N)) and 13C NMR chemical shifts (δC(CH?N)) of the CH?N bridging group were investigated for total of 129 samples of XBAYs. The result shows that the δH(CH?N) and δC(CH?N) have no distinctive linear relationship, which is contrary to the theoretical thought that declared the δH(CH?N) values would increase as the δC(CH?N) values increase. With the in‐depth analysis, we found that the effects of σF and σR of X/Y group on the δH(CH?N) and the δC(CH?N) are opposite; the effects of the substituent specific cross‐interaction effect between X and Y (Δσ2) on the δH(CH?N) and the δC(CH?N) are different; the contributions of parameters in the regression equations of the δH(CH?N) and the δC(CH?N) [Eqns 4 and 7), respectively] also have an obvious difference. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
5.
Nelson L. C. Domingues Paulo R. Olivato Adriana K. C. A. Reis Mirta G. Mondino Filipe S. Lima Roberto Rittner 《Magnetic resonance in chemistry : MRC》2009,47(3):270-272
The complete assignment of the 1H and 13C NMR spectra of the diastereomeric pairs of some α‐arylsulfinyl‐substituted N‐methoxy‐N‐methylpropionamides with the substituents methoxy, methyl, chloro, nitro is reported. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
6.
The 1H and 13C NMR data for 3-azabicyclo[3.3.1]nonanes with OH and OMe substituents at C-6 and C-9 were measured using 1D (DEPT) and 2D (COSY, HSQC, HMBC, NOESY) experiments. Comparison of this NMR data illustrates the effects of stereochemistry and substitution at these positions. 相似文献
7.
《Magnetic resonance in chemistry : MRC》2002,40(7):480-482
1H, 13C and 15N NMR chemical shifts of 10 substituted pyrazolo[1,5‐a]pyrimidines were assigned based on DQF 1H, 1H COSY, PFG 1H, 13C HMQC and PFG 1H,X (X = 13C and 15N) HMBC experiments and on literature data. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
8.
Honeyman B Spalding C Jensen D Haddon RC 《Magnetic resonance in chemistry : MRC》2005,43(12):1053-1056
9-Hydroxyphenalenone is a planar multicyclic beta-keto-enol that demonstrates C2V symmetry on the NMR timescale. Off-axis substitution breaks the molecular symmetry and results in tautomers. 1H and 13C NMR assignments were made for 9-hydroxyphenalenone and three methyl derivatives, and the solution-phase tautomers were determined. 相似文献
9.
《Magnetic resonance in chemistry : MRC》2003,41(8):639-640
15N NMR spectral data for 3‐substituted (chloro, bromo, acetyl, carboxy, carboethoxy, methylsulfanyl, methylsulfinyl, N,N‐dimethylsulfamoyl, nitro) 4(1H)‐quinolinones and their 1‐methyl derivatives are presented. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
10.
《Magnetic resonance in chemistry : MRC》2003,41(6):435-440
cis‐ and trans‐2‐imino‐1,3‐ and ‐3,1‐perhydrobenzoxazines and the N‐methyl derivatives of the latter were synthesized from the corresponding cyclic 1,3‐amino alcohol with cyanogen bromide. The configurations of the studied compounds were confirmed by 1H and 13C NMR spectra. All trans‐fused compounds exist in biased chair–chair conformations as expected, whereas the cis‐fused 1,3‐benzoxazines attain exclusively the O‐in conformations. The cis‐fused 3,1‐benzoxazines, especially the 1‐methyl‐substituted derivatives, tend to favor the N‐out form, obviously owing to the favorable axial orientation of this N‐methyl. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
11.
Belén Rubio‐Ruiz Ana Conejo‐García Miguel A. Gallo Antonio Espinosa Antonio Entrena 《Magnetic resonance in chemistry : MRC》2012,50(6):466-469
1H and 13 C NMR spectral data of 13 new compounds containing a 4‐(dimethylamino)‐ or 4‐(pyrrolidin‐1‐yl)pyridinium moiety linked to the N‐9 or N‐3 nitrogen atom of an adenine moiety were assigned. 1D and 2D NMR experiments (DEPT, HSQC and HMBC) allowed the unequivocal identification of N‐9 and N‐3 isomers. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
12.
《Magnetic resonance in chemistry : MRC》2002,40(3):182-186
15N NMR data of a series of 3‐alkyl[aryl] substituted 5‐trichloromethyl‐1,2‐dimethyl‐1H‐pyrazolium chlorides (where the 3‐substituents are H, Me, Et, n‐Pr, n‐Bu, n‐Pe, n‐Hex, (CH2)5CO2Et, CH2Br, Ph and 4‐Br‐C6H4), are reported. The 15N substituent chemical shifts (SCS) parameters are determined and these data are compared with the 13C SCS values and data obtained by MO calculations. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
13.
Marta Bugaj Piotr A. Baran Piotr Bernatowicz Patrycja Brożek Krystyna Kamieńska‐Trela Adam Krówczyński Bohdan Kamieński 《Magnetic resonance in chemistry : MRC》2009,47(10):830-842
A series of aryl‐substituted enaminoketones and their thio analogues in CDCl3 solution and in the solid state were studied by the use of high‐resolution 1H and 13C as well as 13C cross polarization magic angle spinning (CP MAS) NMR spectra in combination with gauge including atomic orbitals‐density functional theory (GIAO‐DFT) calculations performed at the B3PW91/6–311 + + G(d,p) level of theory using the B3PW91/6‐311 + + G(d,p)‐optimized geometries. The analysis of the 13C NMR spectra in solution was done by using the Incredible Natural Abundance DoublE QUAntum Transfer Experiment (INADEQUATE) technique, whereas trends observed in the 13C shielding constants, calculated for the compounds studied, were a great help in assigning most of the signals in the 13C CP MAS NMR spectra. It was established on the basis of the experimental and theoretical NMR data that both groups of compounds exist in the form of Z‐s‐Z‐s‐E isomers in CDCl3 solution as well as in the solid state, with the NH hydrogen atom involved in intramolecular hydrogen bonding. This conclusion is in agreement with the fact that some of the compounds studied reveal liquid‐crystalline properties. Three‐bond H, H and C, H coupling constants measured in solution played a crucial role in the structure elucidation. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
14.
《Magnetic resonance in chemistry : MRC》2002,40(4):303-306
The 1H and 13C NMR spectroscopic data for alkyl 4‐aryl‐6‐chloro‐5‐formyl‐2‐methyl‐1,4‐dihydopyridine‐3‐carboxylates were fully assigned by combination of one‐ and two‐dimensional experiments (DEPT, HMBC, HMQC, COSY, NOE). Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
15.
Domingues NL Mondino MG Reis AK Rittner R Lima FS Olivato PR 《Magnetic resonance in chemistry : MRC》2007,45(1):87-89
The complete assignments of the 1H and 13C NMR spectra of the some alpha-arylthio and alpha-arylsulfonyl substituted N-methoxy-N-methyl propionamides, bearing methoxy, methyl, chloro, and nitro as substituents at the phenyl ring are reported. 相似文献
16.
《Magnetic resonance in chemistry : MRC》2003,41(9):721-725
The 1H, 13C and 15N NMR spectra in DMSO‐d6 were measured for eight nitraminopyridine N‐oxides, ten 4‐nitropyridine N‐oxides, four 2‐nitraminopyridines and five 4‐nitropyridines. Their chemical shift assignments are based on PFG 1H,X (X = 13C and 15N) HMQC and HMBC experiments. The relative energies for the tautomers of two nitraminopyridine N‐oxides were determined by ab initio HF/6–311G** calculations. A single‐crystal x‐ray structural analysis was made for 4‐methyl‐2‐nitraminopyridine: C6H7O2N3, M = 153.15, triclinic, space group P‐1 (No. 2), a = 7.0275(4), b = 6.8034(3), c = 8.6086(5) Å, α = 103.620(2), β = 90.309(2), γ = 122.215(3)°, V = 334.11(3) Å3, Z = 2. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
17.
18.
《Magnetic resonance in chemistry : MRC》2003,41(7):549-553
The1H and 13C NMR resonances for acridine derivatives 9‐substituted with chloro, allylamino and propargylamino groups were completely assigned using a concerted application of gs‐COSY, gs‐HMQC and gs‐HMBC experiments. 9‐(N‐Allyl)‐ and 9‐(N‐propargyl)acridinamine derivatives present amino–imino tautomerism including a large broadening of 1H and 13C NMR signals at room temperature. To obtain suitable resolution, therefore, these latter compounds were studied at 370 K in DMSO‐d6 solutions and showed a complete shift towards the imino tautomers. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
19.
Vratislav Blechta Stanislav Šabata Jan Sýkora Jiří Hetflejš Ludmila Soukupová Jan Schraml 《Magnetic resonance in chemistry : MRC》2012,50(2):128-134
Infinite dilution 29Si and 13C NMR chemical shifts were determined from concentration dependencies of the shifts in dilute chloroform and acetone solutions of para substituted O‐silylated phenols, 4‐R‐C6H4‐O‐SiR′2R″ (R = Me, MeO, H, F, Cl, NMe2, NH2, and CF3), where the silyl part included groups of different sizes: dimethylsilyl (R′ = Me, R″ = H), trimethylsilyl (R′ = R″ = Me), tert‐butyldimethylsilyl (R′ = Me, R″ = CMe3), and tert‐butyldiphenylsilyl (R′ = C6H5, R″ = CMe3). Dependencies of silicon and C‐1 carbon chemical shifts on Hammett substituent constants are discussed. It is shown that the substituent sensitivity of these chemical shifts is reduced by association with chloroform, the reduction being proportional to the solvent accessible surface of the oxygen atom in the Si‐O‐C link. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
20.
《Magnetic resonance in chemistry : MRC》2002,40(4):293-299
The proton and carbon spectra of new 2,4‐diaryl‐substituted cycloalkyl[d]pyrimidines prepared in a simple one‐pot reaction, are reported. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献