Stereochemicai study of 7-aryl-1,7,8,8a-tetrahydro-3(2H)indolizinones by1H and13C NMR

Stereochemistry of 7-aryl-1,7,8,8a-tetrahydro-3(2H)-indolizinones was studied by¹H and¹³C NMR. Complete assignment of¹H NMR signals and analysis of¹H-¹H coupling constants were performed using the iterative PANIC program. Values of³ J _6,7,³ J _7,8endo, and⁴ J _5,7 allow one to unambiguously identify the correspondingexo- andendo-stereoisomers. For stereoisomers with exo-orientation of H(7), complete assignment of¹³C NMR signals was performed on the basis of analysis of the¹³C-¹H coupling constants using two dimensional heteronuclear shift-correlating spectroscopy.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 591–593, March, 1996.     

1H and 13C spectral assignment of 2(1H)-pyridone derivatives

1H and 13C NMR spectroscopic data for 4-aryl-3,4-dihydro-6-methyl-2(1H)pyridone derivatives were fully assigned by a combination of one- and two- dimensional experiments (DEPT, HMBC, HMQC, COSY, NOE).     

1H and 13C NMR studies of 2-functionalized 5-(methylsulfonyl)-1-phenyl-1H-indoles

The 1H and 13C NMR resonances of thirty 2-functionalized 5-(methylsulfonyl)-1-phenyl-1H-indoles were assigned completely and unequivocally using the concerted application of one- and two-dimensional experiments (DEPT, gs-HMQC and gs-HMBC). Finally, the influence of the 2-substituent of 5-(methylsufonyl)-1-phenyl-1H-indoles on the carbon atoms of the indole moiety was estimated.     

Determination of the structure of 7-diethylamino-4-(1,2,3-triazol-1-yl)-2H-1-benzopyran-2-one derivatives using two-dimensional heteronuclear chemical-shift correlated NMR techniques

¹H and¹³C NMR spectra of 7-diethylamino-4-(1,2,3-triazol-1-yl)-2H-1-benzopyran-2-one derivatives have been studied. The location of the substituent in the 1,2,3-triazole ring was determined by the 2D COLOC method. It was established that the H(3) and H(5) protons in the coumarin moiety experience anisotropic influence of the phenyl subsituent at the C(5) atom in the triazole ring.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1330–1332, July, 1994.     

Assignment of the 1H and 13C NMR signals of some benzofurocoumarins

The complete 1H and 13C NMR assignment of four 6,7-benzo-fused furocoumarins (1-4) and three 3,4-benzo-fused furocoumarins (5-7) has been performed using 1D and 2D NMR techniques, including COSY, HMQC and HMBC experiments.     

Assignment of the 1H and 13C NMR signals of some hydroxyphenylcoumarins

The complete 1H and 13C NMR assignments of six hydroxyphenylcoumarins have been made using 1D and 2D NMR techniques, including COSY, HMQC and HMBC experiments.     

H and C NMR spectroscopy of 9-acridinones

The ¹H and ¹³C NMR spectra of 9-acridinone and its five derivatives dissolved in CDCl₃, CD₃CN and DMSO-d₆ were measured in order to reveal the influence of the constitution of the compounds and features of the solvents on chemical shifts and ¹H-¹H coupling constants. Experimental data were compared with theoretically predicted chemical shifts, on the GIAO/DFT level of theory, for DFT (B3LYP)/6-31G^∗∗ optimized geometries of molecules—also for four other 9-acridinones. This comparison helped to ascribe resonance signals in the spectra to relevant atoms and enabled revelation of relations between chemical shifts and physicochemical features of the compounds. It was found that experimentally or theoretically determined ¹H and ¹³C chemical shifts of selected atoms correlate with theoretically predicted values of dipole moments of the molecules, as well as bond lengths, atomic partial charges and energies of HOMO.     

Specific intramolecular C-H...O interactions in 1-vinyl-2-formylimidazole and 1-vinyl-2-formylbenzimidazole studied by1H and13C NMR spectral data

According to the¹H and¹³C NMR spectral data, the vinyl group in 1-vinyl-2-formylimidazole and 1-vinyl-2-formylbenzimidazole istrans-oriented with respect to the formyl fragment, while the carbonyl group occupies theanti-position with respect to the N atom of pyridine cycle. A specific intramolecular C—H...O interaction of a weak hydrogen bond type is realized between the -H atom of the vinyl group and O atom of the carbonyl group.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1197–1201, May, 1996.     

Complete assignment of 1H and 13C NMR data of some flavonol derivatives

Nine flavonol derivatives were studied. Previously reported NMR data of three of these derivatives were corrected. We report complete assignments of the NMR data for six flavonol derivatives not previously studied.     

Complete assignment of (1)H and (13)C NMR data of dihydroxyflavone derivatives

Six flavone derivatives were studied. Previously reported NMR data of three of these derivatives were corrected and the NMR data for the other three derivatives not studied previously were completely assigned on the basis of the basic 1D and 2D NMR experiments and molecular modeling.     

In situ complexation of rhodium(II) tetracarboxylates with some derivatives of cysteine and related ligands studied by 1H and 13C nuclear magnetic resonance spectroscopy

The complexation of N-phthaloyl, N-formyl, and N,N-dimethyl derivatives of S-methylcysteine methyl ester (both racemic and optically pure) with three dimeric rhodium(II) salts, acetate Rh₂AcO₄, trifluoroacetate Rh₂TFA₄, and (R)-(+)-α-methoxy-α-trifluoromethylphenylacetate Rh₂Mosh₄ was investigated by nuclear magnetic resonance spectroscopy (NMR) at room and lower temperatures. The complexation was carried out in situ, in CDCl₃ solution using titration procedure; the results were examined by the analysis of ¹H and ¹³C NMR chemical shift change (Δδ). The complexation of free S-methyl cysteine and hydrochloride salt of its methyl ester was performed in D₂O solution. For comparison, complexation of some derivatives of leucine, phenylalanine, and proline was examined.

N-phthaloyl and N-formyl derivatives of cysteine formed 1 : 1 and 1 : 2 axial complexes with all dirhodium salts. Rhodium substrates were bonded via sulfur. In one case, the complexation of Rh₂TFA₄ by both sulfur and N-formyl oxygen was noted. Similar complexation of Rh₂TFA₄, via CHO group, was found for N-formyl derivatives of leucine, phenylalanine, and proline. For N,N-dimethyl derivative of cysteine, both N and S atoms were involved in bonding. At room temperature, in all cases, ligand exchange was fast on the NMR timescale.     

1H and13C NMR studies on lanthanide complexes with proline and hydroxyproline

The formation and the mode of coordination of rare earth (Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Lu) complexes with proline and hydroxyproline have been investigated by¹H and¹³C NMR spectral techniques. It has been established that the nitrogen and the carboxyl group of the ligands are involved in complexation, and that the OH^– group of hydroxyproline does not participate in coordination.

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¹H und¹³C NMR Untersuchungen an Lanthanid-Komplexen mit Prolin und Hydroxyprolin

Zusammenfassung Die Bildung und die Koordination von seltenen Erden (Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Lu) in Komplexen mit Prolin und Hydroxyprolin wurden mit Hilfe von¹H- und¹³C-NMR-Spektroskopie untersucht. Es wurde festgestellt, daß in den Komplexen der Stickstoff und der Carboxylsauerstoff der Liganden koordinieren. Die OH^–-Gruppe von Hydroxyprolin nimmt keinen Anteil an der Koordinierung.

     

1H and 13C NMR spectral assignments of pyridinium salts linked to a N‐9 or N‐3 adenine moiety

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.     

1H and 13C NMR spectral assignments of some natural abietane diterpenoids

An NMR study of 11 naturally occurring abietane diterpenoids is described. In addition to one‐dimensional NMR methods, including DPFGSE 1D‐NOE spectra, two‐dimensional shift‐correlated experiments [¹H,¹H COSY, ¹H,¹³C‐gHSQC ¹J(C,H) and ¹H,¹³C‐gHMBC ⁿJ(C,H) (n = 2 and 3)] were used for the complete and unambiguous ¹H and ¹³C chemical shift assignments of these substances. Copyright © 2003 John Wiley & Sons, Ltd.     

Synthesis and complete assignment of the 1H and 13C NMR signals of some oxopyrancoumarin and oxofuropyrancoumarin derivatives

The synthesis of four pyranocoumarins starting from phloroglucinol and the complete (1)H and (13)C NMR assignment of seven pyranocoumarins has been performed using 1D and 2D NMR techniques including COSY, HMQC and HMBC experiments.     

1H and 13C chemical shifts for some 6,6a-dihydrochromeno(3,4-b)chromene derivatives

The 1H and 13C NMR resonances of five 6,6a-dihydrochromeno(3,4-b)chromene derivatives were assigned completely with certainty using a concerted application of one- and two-dimensional experiments (DEPT, gs-COSY, gs-HMQC and gs-HMBC).     

Gold(III)pentafluorophenylarylazoimidazole: Synthesis and spectral (H, C, COSY, HMQC NMR) characterisation

Reaction of [Au^III(C₆F₅)₃(tht)] with RaaiR′ in dichloromethane medium leads to [Au^III(C₆F₅)₃ (RaaiR′)] [RaaiR′=p-R-C₆H₄-N=N-C₃H₂-NN-l-R′, (1-3), R = H (a), Me (b), Cl (c) and R′= Me (1), CH₂CH₃ (2), CH₂Ph (3), tht is tetrahydrothiophen]. The nine new complexes are characterised by ES/MS as well as FAB, IR and multinuclear NMR (¹H,¹³C,¹⁹F) spectroscopic studies. In addition to dimensional NMR studies as¹H,¹H COSY and¹H¹³C HMQC permit complete assignment of the complexes in the solution phase.     

1-(1-Adamantyl)diaziridine

The reaction of 1-aminoadamantane with CH₂O and H₂NOSO₃H in the presence of K₂CO₃ under phase-transfer conditions leads to hitherto unknown 1-(1-adamantyl)diaziridine and (1-adamantyl)aminoacetonitrile, characterized by spectral data. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 861–862, April, 1997.     

Warifteine and methylwarifteine: 1H and 13C assignments by two‐dimensional NMR spectroscopy

The identity and structures of warifteine and methylwarifteine, two tertiary bisbenzylisoquinoline alkaloids of an unusual type, were elucidated and verified by 2D NMR spectroscopy. Complete ¹H and ¹³C NMR spectral assignments were obtained. Copyright © 2003 John Wiley & Sons, Ltd.     

1H and 13C NMR spectral assignment of alkyl and polyamine-linked bis(2-thioxo-[1,3,5]-thiadiazinan-3-yl) carboxylic acids

The 1H and 13C NMR spectroscopic data for alkyl and polyamine-linked bis(2-thioxo-[1,3,5]thiadiazinan-3-yl) carboxylic acids, prepared from alkyl diamines and N4-(benzyl) spermidine have been fully assigned by combination of one- and two-dimensional experiments (DEPT, HMBC, HMQC, COSY).