Preparation, reactions, and spectroscopic investigation of the 1,1,3,3-tetramethylimidazolidinium and 1,1,4,4-tetramethylpiperazonium dications

1987 ◽  
Vol 65 (11) ◽  
pp. 2526-2528 ◽  
Author(s):  
J. Alan Creighton ◽  
Michael J. Taylor
Keyword(s):  
Spectroscopic Investigation ◽  
Nmr Spectra ◽  
Single Step ◽  
Complex Ions ◽  
Quaternary Nitrogen ◽  
Nmr Data ◽  
Doubly Charged

The title dications are prepared in a single step by the reaction of N,N,N′,N′-tetramethyl-1,2-diaminoethane (tmen) with the halogenoalkanes CH2X2 (X = Cl, Br, or I)orCH2XCH2X (X = Cl or Br), respectively. These bulky dications are useful for the precipitation of complex ions from solution, and show selectivity for doubly-charged anions. Tmen also reacts with CBr4 to yield a dibromo-imidazolidinium heterocyclic dication, whereas reaction with CHBr2CHBr2 produces the dihydrobromide of tmen. Vibrational and nmr spectra are reported, and the protons of the CH2 group between the two quaternary nitrogen atoms of the tetramethylimidazolidinium dication are shown from the nmr data to possess acidic character.

NMR spectroscopic investigation of p-substituted 2,4,4,6-tetraphenyl-1,4-dihydropyridines and their oxa and thia analogues

1989 ◽  
Vol 54 (7) ◽  
pp. 1854-1869 ◽  
Author(s):  
Marián Schwarz ◽  
Petr Trška ◽  
Josef Kuthan
Keyword(s):  
Nmr Spectroscopy ◽  
Trifluoroacetic Acid ◽  
Spectroscopic Investigation ◽  
Nmr Spectra ◽  
Dynamic Equilibrium

The 1H, 13C and 19F NMR spectra of photochromic p-substituted 2,4,4,6-tetraphenyl-1,4-dihydropyridines IIa-IIg, 1-methyl-2,4,4,6-tetraphenyl-1,4-dihydropyridines IIIa-IIIg, 2,4,4,6-tetraphenyl-4H-pyrans IVa-IVh, and 2,4,4,6-tetraphenyl-4H-thiopyran V were inspected; it was found that compounds IIa-IIg occur in a dynamic equilibrium with their dihydro tautomer VIa-VIg. Also deuteriodeprotonation of IIa and IIIa and their reaction with trifluoroacetic acid were investigated by NMR spectroscopy.

scholarly journals Five sesquiterpenes from the root Aucklandia lappa Decne.

2019 ◽  
pp. 5-11
Author(s):  
Chjuo Fuguan ◽  
Seesregdorj S ◽  
Gerelt-Od Ya
Keyword(s):  
Phenolic Compounds ◽  
Nmr Spectra ◽  
Previous Literature ◽  
Two Dimensional ◽  
Nmr Data ◽  
Nmr Techniques ◽  
The One ◽  
Dehydrocostus Lactone ◽  
First Time

The four sesquiterpenes calameone (1), dehydrocostus lactone (2), aristolone (3), alantolactone (4) and one triterpenoid α-amyrine (5), simple phenolic compounds such as 4-hydroxybenzaldehyde, (6), piceol (7), apocynin (8), dihydroconiferyl (9) and coniferyl (10) have been identified by using the proton and carbon NMR spectra which were isolated from a dichloromethane extract of the roots of Aucklandia lappa Decne. Their structures were established by the one‐and two‐dimensional NMR techniques including DEPT, COSY and HMBC spectroscopy. This work examined proton and carbon NMR data of calameone (1) and aristolone (3) for the first time, which had not yet been fully studied in previous literature. Рүда ургамлын (Aucklandia lappa Decne.) терпент нэгдлийн судалгаа Хураангуй: Рүда ургамлын үндэсний дихлорметаны ханднаас хроматографийн аргуудаар эвдесман хэлбэрийн сесквитерпен каламеон (1), аристолон (3), алантолактон (4), гвяан хэлбэрийн сесквитерпен дегидрокостасын лактон (2), тритерпеноид α-амурин (5) болон энгийн фенолт нэгдэл 4-гидроксибензальдегид (6), пицелол (7), апоцинин (8), дегидрокониферол (9), кониферол (10) зэрэг бодисыг химийн цэвэр байдалтай ялгав. Эдгээр бодисын бүтэц байгуулалтыг нэг болон хоёр хэмжээст ЦСР-ын DEPT, COSY, HMBC спектроскопийн аргаар таньж тодорхойлов. Урьд өмнө каламеон (1), аристолон (3) бодисуудын устөрөгч ба нүүрстөрөгчийн атомуудын химийн шилжилтийн утгуудад оноолт бүрэн хийгдээгүй байсан ба энэ хоёр бодисын оноолтыг гүйцээж хийв. Түлхүүр үг: Терпеноид, сесквитерпент лактон, дегидрокостасын лактон, ЦСР.

scholarly journals The NMR Spin Systems of Scutellaria 8β,13-Epoxy-neo-clerod-3-en-15,16-olides and Revision of 1H and 13C NMR Spectra Reported Data

2020 ◽  
Vol 15 (10) ◽  
pp. 1934578X2093378
Author(s):  
Josep Coll Toledano
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Spin Systems ◽  
13C Nmr Spectra ◽  
1H And 13C Nmr ◽  
Nmr Data ◽  
Reported Data ◽  
New Compounds ◽  
C Nmr ◽  
Shielding Effects

The present review of NMR spectroscopic structural elucidation data of new compounds isolated from Scutellaria species is focused on the title compounds, displaying a peculiar 13-spiro feature. It contains a compilation of 1H and 13C NMR data of these diterpenoids grouped by similar substitution patterns. Comparing shielding effects pointed out not only the identity of some compounds (already reported) but also potential misassignments and convenient revisions to get unambiguous structural proposals.

Ein [1,3,4]Thiazaphospholidin, Darstellung und NMR-Daten / A [1,3,4]Thiazaphospholidine, Preparation and NMR Data

1987 ◽  
Vol 42 (1) ◽  
pp. 115-117 ◽  
Author(s):  
Gernot Heckmann ◽  
Ekkehard Fluck ◽  
Peter Kuhm
Keyword(s):  
Nmr Spectra ◽  
Resonance Mode ◽  
Triple Resonance ◽  
H Nmr ◽  
Nmr Data

Abstract Preparation and properties of a [1,3,4]thiazaphospholidine are described. The 31P. 13C and 1H NMR spectra in double and triple resonance mode are recorded and discussed in detail.

Anwendung der 15N-NMR-Spektroskopie zur Charakterisierung reaktiver, koordinativ ungesättigter Zinn-, Bleiund Phosphor-Stickstoff-Verbindungen / Application of 15N-NMR Spectroscopy to the Characterization of Reactive, Coordinatively Unsaturated Tin-, Lead- and Phosphorus-Nitrogen Compounds

1987 ◽  
Vol 42 (12) ◽  
pp. 1515-1519 ◽  
Author(s):  
Carin Stader ◽  
Bernd Wrackmeyer
Keyword(s):  
Nmr Spectra ◽  
Pulse Sequence ◽  
Coupling Constants ◽  
Spin Coupling ◽  
15N Nmr ◽  
Nmr Data ◽  
15N Nmr Spectroscopy ◽  
Spin Coupling Constants ◽  
Spin Spin Coupling

AbstractThe basic INEPT pulse sequence proved most useful for recording 15N NMR spectra at natural abundance of bis(amino)stannvlenes (1). -plumbylenes (2) and of imino-amino-λ2-phosphanes (3), where the nitrogen atoms carry bulky substituents like Me3Si-, t-Bu-, 2.4.4-trimethyl-2- pentyl-groups (t-Oct-groups) or are part of the 2.2.6.6-tetramethylpiperidinyl group. The sensitiv­ity of this technique is proved by the observation of 117/119Sn or 207Pb satellites owing to spin-spin coupling constants 1J(117/119Sn15N) and 1J(117/119Pb15N), respectively. NMR data of bis[bis(trimethylsilyl)methyl]tin (4) are reported in order to corroborate the arguments for the interpretation of the δ(15N) and 1J(119Sn15N) data. The 15N NMR data of the λ2-phosphanes (3) indicate a bonding situation similar to that in triazenes.

The 1H-NMR Spectra of the Biflavones Isocryptomerin and Cryptomerin B - a Critical Comment on Two Recent Publications on the Biflavone Patterns of Selaginella selaginoides and S. denticulata

1996 ◽  
Vol 51 (9-10) ◽  
pp. 757-758 ◽  
Author(s):  
Hans Geiger ◽  
Kenneth R. Markham
Keyword(s):  
1H Nmr ◽  
Nmr Spectra ◽  
Critical Comment ◽  
1H Nmr Spectra ◽  
Current Paper ◽  
Published Data ◽  
Supportive Evidence ◽  
H Nmr ◽  
Nmr Data

Two recent reports from another laboratory on hinokiflavone and robustaflavone in S. selaginoides, and hinokiflavone, isocryptom erin, cryptomerin B and amentoflavone 7-methylether in S. denticulata are shown to be based on 1H -NMR data that are inconsistent with the biflavone structures proposed. In the current paper a comparison of the 1H -nmr spectra is made both with published data and with new data derived from authentic samples. It is concluded that in both reports, only for am entoflavone the NMR data provide convincing supportive evidence. These reports are considered therefore to merely confirm an earlier identification of am entoflavone in these species

scholarly journals 1 H NMR spectra dataset and solid-state NMR data of cowpea ( Vigna unguiculata )

Data in Brief ◽  
2017 ◽  
Vol 11 ◽  
pp. 136-146 ◽  
Author(s):  
Elenilson G. Alves Filho ◽  
Lorena M.A. Silva ◽  
Elizita M. Teofilo ◽  
Flemming H. Larsen ◽  
Edy S. de Brito
Keyword(s):  
Solid State ◽  
Vigna Unguiculata ◽  
Solid State Nmr ◽  
Nmr Spectra ◽  
H Nmr ◽  
Nmr Data

scholarly journals FID-Net: A Versatile Deep Neural Network Architecture for NMR Spectral Reconstruction and Virtual Decoupling

2020 ◽  
Author(s):  
Gogulan Karunanithy ◽  
Flemming Hansen
Keyword(s):  
Neural Network ◽  
Network Architecture ◽  
Nmr Spectra ◽  
Deep Neural Network ◽  
Protein Nmr ◽  
Single Shot ◽  
Neural Network Architecture ◽  
Diverse Range ◽  
Nmr Data ◽  
Wide Range

<p>In recent years, the transformative potential of deep neural networks (DNNs) for analysing and interpreting NMR data has clearly been recognised. However, most applications of DNNs in NMR to date either struggle to outperform existing methodologies or are limited in scope to a narrow range of data that closely resemble the data that the network was trained on. These limitations have prevented a widescale uptake of DNNs in NMR. Addressing this, we introduce FID-Net, a deep neural network architecture inspired by WaveNet, for performing analyses on time domain NMR data. We first demonstrate the effectiveness of this architecture in reconstructing non-uniformly sampled (NUS) biomolecular NMR spectra. It is shown that a single network is able to reconstruct a diverse range of 2D NUS spectra that have been obtained with arbitrary sampling schedules, with a range of sweep widths, and a variety of other acquisition parameters. The performance of the trained FID-Net in this case exceeds or matches existing methods currently used for the reconstruction of NUS NMR spectra. Secondly, we present a network based on the FID-Net architecture that can efficiently virtually decouple <sup>13</sup>C<sub>α</sub>-<sup>13</sup>C<sub>β</sub> couplings in HNCA protein NMR spectra in a single shot analysis, while at the same time leaving glycine residues unmodulated. The ability for these DNNs to work effectively in a wide range of scenarios, without retraining, paves the way for their widespread usage in analysing NMR data. </p>

scholarly journals Direct Access to (±)-10-Desbromoarborescidine A from Tryptamine and Pentan-1,5-diol

2019 ◽  
Author(s):  
Apurba Ranjan Sahoo ◽  
Gummidi Lalitha ◽  
V. Murugesh ◽  
Christian Bruneau ◽  
Gangavaram V. M. Sharma ◽  
...  
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Ruthenium Complex ◽  
Single Step ◽  
Direct Access ◽  
Condensation Process ◽  
13C Nmr Spectra ◽  
Synthetic Strategy ◽  
Supporting Material

A single step synthetic strategy for (±)10- Desbromoarborescidine A is described. Starting from tryptamine and pentan-1,5-diol, this acceptorless dehydrogenative condensation process is efficiently catalyzed by a ruthenium complex featuring proton-responsive phosphine pyridone ligand.<div>Manuscript is available supporting material is available and includes experimental procedures, characterization of compounds, 1H, 13C NMR spectra and chromatograms.</div>

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