The reaction of (η5-cyclopentadienyl)dicarbonyliron(2-thienoyl) with acetylenes; a mechanistic study using proton nuclear magnetic resonance, and application in synthesis

1990 ◽  
Vol 68 (11) ◽  
pp. 1979-1987 ◽  
Author(s):  
Ian R. Butler
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Carbon Monoxide ◽  
Reaction Mechanism ◽  
Proton Nuclear Magnetic Resonance ◽  
Mechanistic Study ◽  
Reaction Products ◽  
Thermal Reactions ◽  
H Nmr ◽  
Substituted Acetylenes ◽  
Acetylene Carbon

The thermal reactions of dicarbonyl-η5-cyclopentadienyl(2-thienoyl)iron with a series of substituted acetylenes to give indenones and cyclopentathiophenones have been reinvestigated. The results obtained support a reaction mechanism involving initial acetylene insertion followed by that of carbon monoxide, in contradiction to the previously reported results. The reaction products were identified and characterized primarily using 2D 1H nmr spectroscopy. Keywords: acetylene, carbon monoxide, iron, indenone, mechanism, thienyl.

scholarly journals Kajian Regiokimia Markovnikov Melalui Mekanisme Reaksi Hidrasi Alkuna Terminal pada Etinilestradiol dengan Katalis FeCl3

2021 ◽  
Vol 6 (1) ◽  
pp. 39
Author(s):  
Hotma Rotua Br. Simbolon ◽  
Rymond Jusuf Rumampuk ◽  
Anderson Arnold Aloanis
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Reaction Mechanism ◽  
Reaction Rate ◽  
Methyl Ketone ◽  
Proton Nuclear Magnetic Resonance ◽  
Hydration Reaction ◽  
Terminal Alkynes ◽  
Terminal Alkyne ◽  
Reaction Products ◽  
Reaction Conditions

The terminal alkynes hydration reaction on 17α-ethynylestradiol (1) with FeCl3 catalyst mediated by dichloromethane aims to determine the reaction products produced and to conduct a Markovnikov regiochemistry study through the proposed reaction mechanism. The reaction conditions were carried out at a temperature of 50oC (48 hours) and 60oC (19 hours), the separation of the reaction properties was carried out using Gravity Column Chromatography, and the reaction products were identification using by Proton Nuclear Magnetic Resonance (1H-NMR). Here we describe the process of the FeCl3 catalyst forming a coordination complex with the terminal alkyne, which is then addition by nucleophilic water following Markovnikov's regiochemistry to finally produce the product of a methyl ketone, 17α-acetylestradiol (6). The catalyst used is a cationic ligand coordinate, where Fe3+ is a Lewis acid and Cl3- acts as a ligand. The dichloromethane solvent used can also increase the reaction rate.

scholarly journals Proton Nuclear Magnetic Resonance Metabolomics Corroborates Serine Hydroxymethyltransferase as the Primary Target of 2-Aminoacrylate in a ridA Mutant of Salmonella enterica

mSystems ◽  
2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Andrew J. Borchert ◽  
Goncalo J. Gouveia ◽  
Arthur S. Edison ◽  
Diana M. Downs
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Metabolic Stress ◽  
Metabolic Changes ◽  
Serine Hydroxymethyltransferase ◽  
Proton Nuclear Magnetic Resonance ◽  
Growth Defect ◽  
Nutrient Supplementation ◽  
Content Type ◽  
H Nmr

ABSTRACT The reactive intermediate deaminase RidA (EC 3.5.99.10) is conserved across all domains of life and deaminates reactive enamine species. When Salmonella enterica ridA mutants are grown in minimal medium, 2-aminoacrylate (2AA) accumulates, damages several pyridoxal 5′-phosphate (PLP)-dependent enzymes, and elicits an observable growth defect. Genetic studies suggested that damage to serine hydroxymethyltransferase (GlyA), and the resultant depletion of 5,10-methelenetetrahydrofolate (5,10-mTHF), was responsible for the observed growth defect. However, the downstream metabolic consequence from GlyA damage by 2AA remains relatively unexplored. This study sought to use untargeted proton nuclear magnetic resonance (1H NMR) metabolomics to determine whether the metabolic state of an S. enterica ridA mutant was accurately reflected by characterizing growth phenotypes. The data supported the conclusion that metabolic changes in a ridA mutant were due to the IlvA-dependent generation of 2AA, and that the majority of these changes were a consequence of damage to GlyA. While many of the metabolic differences for a ridA mutant could be explained, changes in some metabolites were not easily modeled, suggesting that additional levels of metabolic complexity remain to be unraveled. IMPORTANCE The accumulation of the reactive enamine intermediate 2-aminoacrylate (2AA) elicits global metabolic stress in many prokaryotes and eukaryotes by simultaneously damaging multiple pyridoxal 5′-phosphate (PLP)-dependent enzymes. This work employed 1H NMR to expand our understanding of the consequence(s) of 2AA stress on metabolite pools and effectively identify the metabolic changes stemming from one damaged target: GlyA. This study shows that nutrient supplementation during 1H NMR metabolomics experiments can disentangle complex metabolic outcomes stemming from a general metabolic stress. Metabolomics shows great potential to complement classical reductionist approaches to cost-effectively accelerate the rate of progress in expanding our global understanding of metabolic network structure and physiology. To that end, this work demonstrates the utility in implementing nutrient supplementation and genetic perturbation into metabolomics workflows as a means to connect metabolic outputs to physiological phenomena and establish causal relationships.

scholarly journals Correlations between Proton Nuclear Magnetic Resonance Imaging and Retrospective Histochemical Images in Experimental Cerebral Infarction

1985 ◽  
Vol 5 (2) ◽  
pp. 267-274 ◽  
Author(s):  
Hiroyuki Kato ◽  
Kyuya Kogure ◽  
Hitoshi Ohtomo ◽  
Muneshige Tobita ◽  
Shigeru Matsui ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Spin Echo ◽  
Proton Nuclear Magnetic Resonance ◽  
Nmr Imaging ◽  
Resonance Imaging ◽  
H Nmr ◽  
Experimental Cerebral Infarction ◽  
Nuclear Magnetic

Evaluation of ischemic brain injury in experimental cerebral infarction in gerbils and rats was performed by means of both proton nuclear magnetic resonance imaging ([1H]NMR-CT) and various histochemical analyses. In vivo nuclear magnetic resonance (NMR) imaging was carried out employing saturation recovery, inversion recovery, and spin echo pulse sequences. Spatial resolution of the images was excellent. The ischemic lesions were detected with a remarkable contrast in inversion recovery and spin echo images within a few hours after insult. Those changes in NMR images consistently corresponded with the various retrospective histochemical observations, especially with methods related to brain edema (K+ staining) rather than structural (enzymatic) studies. Calculated T1 and T2 relaxation times indicated the evolution of the edema state in the brain in situ. They correlated excellently with the retrospective water content measurement. As a result, detailed characterization of the edema state induced by cerebral ischemia was possible in vivo using [1H]NMR imaging.

scholarly journals 1H Nuclear Magnetic Resonance: A Future Approach to the Metabolic Profiling of Psychedelics in Human Biofluids?

2021 ◽  
Vol 12 ◽  
Author(s):  
Sylvana Vilca-Melendez ◽  
Malin V. Uthaug ◽  
Julian L. Griffin
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Metabolic Profiling ◽  
Proton Nuclear Magnetic Resonance ◽  
Future Directions ◽  
H Nmr ◽  
Nuclear Magnetic ◽  
Psychedelic Research

While psychedelics may have therapeutic potential for treating mental health disorders such as depression, further research is needed to better understand their biological effects and mechanisms of action when considering the development of future novel therapy approaches. Psychedelic research could potentially benefit from the integration of metabonomics by proton nuclear magnetic resonance (1H NMR) spectroscopy which is an analytical chemistry-based approach that can measure the breakdown of drugs into their metabolites and their metabolic consequences from various biofluids. We have performed a systematic review with the primary aim of exploring published literature where 1H NMR analysed psychedelic substances including psilocin, lysergic acid diethylamide (LSD), LSD derivatives, N,N-dimethyltryptamine (DMT), 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) and bufotenin. The second aim was to assess the benefits and limitations of 1H NMR spectroscopy-based metabolomics as a tool in psychedelic research and the final aim was to explore potential future directions. We found that the most current use of 1H NMR in psychedelic research has been for the structural elucidation and analytical characterisation of psychedelic molecules and that no papers used 1H NMR in the metabolic profiling of biofluids, thus exposing a current research gap and the underuse of 1H NMR. The efficacy of 1H NMR spectroscopy was also compared to mass spectrometry, where both metabonomics techniques have previously shown to be appropriate for biofluid analysis in other applications. Additionally, potential future directions for psychedelic research were identified as real-time NMR, in vivo1H nuclear magnetic resonance spectroscopy (MRS) and 1H NMR studies of the gut microbiome. Further psychedelic studies need to be conducted that incorporate the use of 1H NMR spectroscopy in the analysis of metabolites both in the peripheral biofluids and in vivo to determine whether it will be an effective future approach for clinical and naturalistic research.

Synthesis of new 3H-chromeno[2,3-d]pyrimidine-4,6(5H,7H)-diones via the tandem intramolecular Pinner/Dimroth rearrangement

2018 ◽  
Vol 24 (1) ◽  
pp. 31-35 ◽  
Author(s):  
Nasrin Karimi ◽  
Abolghasem Davoodnia ◽  
Mehdi Pordel
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Proton Nuclear Magnetic Resonance ◽  
Phosphoryl Chloride ◽  
Dimroth Rearrangement ◽  
H Nmr ◽  
High Yields ◽  
Aliphatic Carboxylic Acids ◽  
C Nmr ◽  
Nuclear Magnetic

Abstract The reaction of 2-amino-4-aryl-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitriles with excess aliphatic carboxylic acids in the presence of phosphoryl chloride (POCl3) afforded new 2-alkyl-5-aryl-8,8-dimethyl-8,9-dihydro-3H-chromeno[2,3-d]pyrimidine-4,6(5H,7H)-diones in high yields. The suggested mechanism involves a tandem intramolecular Pinner/Dimroth rearrangement. The synthesized compounds were characterized by infrared (IR), proton nuclear magnetic resonance (1H NMR), carbon-13 nuclear magnetic resonance (13C NMR) and elemental analysis.

Serum analysis by1H Nuclear Magnetic Resonance spectroscopy: a new tool for distinguishing neuromyelitis optica from multiple sclerosis

2013 ◽  
Vol 20 (5) ◽  
pp. 558-565 ◽  
Author(s):  
F-M Moussallieh ◽  
K Elbayed ◽  
JB Chanson ◽  
G Rudolf ◽  
M Piotto ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Neuromyelitis Optica ◽  
Demyelinating Diseases ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
H Nmr ◽  
Nuclear Magnetic

Background:Neuromyelitis optica (NMO) and multiple sclerosis (MS), two inflammatory demyelinating diseases, are characterized by different therapeutic strategies. Currently, the only biological diagnostic tool available to distinguish NMO from MS is the specific serum autoantibody that targets aquaporin 4, but its sensitivity is low.Objective:To assess the diagnostic accuracy of metabolomic biomarker profiles in these two neurological conditions, compared to control patients.Methods:We acquired serum spectra (47 MS, 44 NMO and 42 controls) using proton nuclear magnetic resonance (1H-NMR) spectroscopy. We used multivariate pattern recognition analysis to identify disease-specific metabolic profiles.Results:The1H-NMR spectroscopic analysis evidenced two metabolites, originating probably from astrocytes, scyllo-inositol and acetate, as promising serum biomarkers of MS and NMO, respectively. In 87.8% of MS patients, scyllo-inositol increased 0.15 to 3-fold, compared to controls and in 74.3% of NMO patients, acetate increased 0.4 to 7-fold, compared to controls. Using these two metabolites simultaneously, we can discriminate MS versus NMO patients (sensitivity, 94.3%; specificity, 90.2%).Conclusion:This study demonstrates the potential of1H-NMR spectroscopy of serum as a novel, promising analytical tool to discriminate populations of patients affected by NMO or MS.

Titanocene derivatives of purine and adenine. Synthesis and characterization of reaction products with (η5-C5H5)2Ti(CO)2, (η5-C5H5)2TiCl, and (η5-C5H5)2TiCl2

1986 ◽  
Vol 64 (4) ◽  
pp. 751-759 ◽  
Author(s):  
Daniel Cozak ◽  
Abdelhakim Mardhy ◽  
André Morneau
Keyword(s):  
Carbon Monoxide ◽  
Metal Complex ◽  
Elemental Analysis ◽  
Synthesis And Characterization ◽  
Reaction Products ◽  
First Order ◽  
H Nmr ◽  
New Compounds ◽  
Derivatives Of

The reaction of CpTi(CO)2 (1), Cp2TiCl (2), and Cp2TiCl2 (3) (Cp = η5-C5H5) with purine (PuH) and adenine (AdH) in organic solvents is described. The compound 1 reacts with both molecules in an oxidative fashion giving Cp2Ti(C5H3N4)(C5H4N4) (4) and (Cp2Ti)2(C5H3N5) (5) with concomitant liberation of molecular carbon monoxide and hydrogen (4:1) following a first order rate law in metal complex. The compound 2 forms an adduct compound Cp2TiCl(C5H4N4) (6) with PuH. Monosubstituted derivatives Cp2TiCl(C5H3N4) (7) and Cp2TiCl(C5H4N5) (8) are formed from the reaction of the deprotonated bases with 3. In addition to the usual elemental analysis, the characteristic ir, 1H nmr, epr, and ms results are given for the new compounds.

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