scholarly journals Molecular rearrangement of pyrazino[2,3-c]quinolin-5(6H)-ones during their reaction with isocyanic acid

2021 ◽  
Author(s):  
Antonín Klásek ◽  
Antonín Lyčka ◽  
Filip Křemen ◽  
Aleš Růžička ◽  
Michal Rouchal
Keyword(s):  
Nmr Spectra ◽  
Ethylene Diamine ◽  
Isocyanic Acid ◽  
Molecular Rearrangement ◽  
X Ray ◽  
Hydantoin Derivatives

A new tetrahydropyrazino[2,3-c]quinolin-5(6H)-ones were prepared from 3-chloroquinoline-2,4(1H,3H)-diones and ethylene diamine. In their reaction with HNCO, an unprecedented molecular rearrangement produced new types of hydantoin derivatives. All prepared compounds are characterized using their 1H, 13C, and 15N NMR spectra and the results of the X-ray analysis are also presented. A proposed mechanism of rearrangement is discussed in this essay.

The Electron Effect of Aromatic Group: Control Conformation of 2-Aromatic Cyclododecanone Derivatives

2020 ◽  
Vol 24 (10) ◽  
pp. 1139-1147
Author(s):  
Yang Mingyan ◽  
Wang Daoquan ◽  
Wang Mingan
Keyword(s):  
1H Nmr ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Coupling Constants ◽  
The Other ◽  
Repulsive Interaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Effect ◽  
Group Control

2-Phenylcyclododecanone and 2-cyclohexylcyclododecanone derivatives were synthesized and characterized by 1H NMR, 13C NMR, HR-ESI-MS and X-ray diffraction. Their preferred conformations were analyzed by the coupling constants in the 1H NMR spectra and X-ray diffraction, which showed the skeleton ring of these derivatives containing [3333]-2-one conformation, and the phenyl groups were located at the side-exo position of [3333]-2-one conformation due to the strong π-π repulsive interaction between the π- electron of benzene ring and π-electron of carbonyl group. The cyclohexyl groups were located at the corner-syn or the side-exo position of [3333]-2-one conformation depending on the hindrance of the other substituted groups. The π-π electron effect played a crucial role in efficiently controlling the preferred conformation of 2-aromatic cyclododecanone and the other 2-aromatic macrocyclic derivatives with the similar preferred square and rectangular conformations.

Preparation, properties and structure of some intermediate nido- and arachno-monocarbaboranes

1981 ◽  
Vol 46 (10) ◽  
pp. 2345-2353 ◽  
Author(s):  
Karel Baše ◽  
Bohumil Štíbr ◽  
Jiří Dolanský ◽  
Josef Duben
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Nmr Spectra ◽  
Liquid Ammonia ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Starting Compound

The 6-N(CH3)3-6-CB9H11 carbaborane reacts with sodium in liquid ammonia with the formation of 6-CB9H12- which was used as a starting compound for preparing the 4-CB8H14, 9-L-6-CB9H13 (L = (CH3)2S, CH3CN and P(C6H5)3), 1-(η5-C5H5)-1,2-FeCB9H10-, and 2,3-(η5-C5H5)2-2,31-Co2CB9H10- carboranes. The 4-CB8H14 compound was dehydrogenated at 623 K to give 4-(7)-CB8H12 carborane. Base degradation of 6-N(CH3)3-6-CB9H11 in methanol resulted in the formation of 3,4-μ-N(CH3)3CH-B5H10. The structure of all compounds was proposed on the basis of their 11B and 1H NMR spectra and X-ray diffraction was used in the case of the transition metal complexes.

Axially Chiral Bis(α-amino Acid)s and Their Deamino Analogues. Synthesis and Configurational Assignment

1998 ◽  
Vol 63 (2) ◽  
pp. 211-221 ◽  
Author(s):  
Miloš Tichý ◽  
Luděk Ridvan ◽  
Miloš Buděšínský ◽  
Jiří Závada ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Amino Acid ◽  
Nmr Spectra ◽  
Building Blocks ◽  
X Ray Diffraction ◽  
Amino Groups ◽  
X Ray ◽  
Configurational Assignment ◽  
Symmetry Properties ◽  
Axially Chiral ◽  
Polymeric Structures

The axially chiral bis(α-amino acid)s cis-2 and trans-2 as possible building blocks for polymeric structures of novel type of helicity were prepared. Their configuration has been determined by NMR spectroscopy and, in the case of the trans-isomer, confirmed by single-crystal X-ray diffraction. Analogous pair of stereoisomeric diacids cis-3 and trans-3, devoid of the amino groups, was also prepared and their configuration assigned. The observed differences in the NMR spectra of cis- and trans-isomers of 2 and 3 are discussed from the viewpoint of their different symmetry properties.

Unusual Rearrangement of Naphthalene in the Synthesis of a Novel B8-B8-Bridged Derivative in the [(1,2-C2B9H11)2-3-Co]- Series. X-Ray Structure and 11B NMR Spectra of [8,8'-μ-(CH2-C9H6)-(1,2-C2B9H10)2-3-Co]- (CH3)4N+

1997 ◽  
Vol 62 (5) ◽  
pp. 746-751 ◽  
Author(s):  
Andreas Franken ◽  
Jaromír Plešek ◽  
Christiane Nachtigal
Keyword(s):  
Nmr Spectroscopy ◽  
Single Crystal ◽  
Nucleophilic Substitution ◽  
Nmr Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Unusual Rearrangement ◽  
Multinuclear Nmr Spectroscopy ◽  
11B Nmr ◽  
Isolated Compound

On treatment of the [(1,2-C2B9H11)2Co]- ion with naphthalene in presence of AlCl3 a remarkably bridged [8,8'-μ-(CH2-C9H6)-(1,2-C2B9H10)2-3-Co]- ion is obtained as a single isolated compound. The triatomic -CH2-C9H6- bridge is derived from the rearranged naphthalene nucleus. The mechanism of this reaction is obscure but it does resemble the "Electrophile-Induced Nucleophilic Substitution" reported earlier. The structure of the compound was established by multinuclear NMR spectroscopy and by single crystal X-ray diffraction.

The 1H NMR spectra and fluxional behaviour of [Mo(η-C5H5)(CO)(CNR)3][PF6] complexes (R = Me, Et, Pr OR Bu ): the x-ray structure of [Mo(ν-C5H5)(CO)(CNB )3][PF6]

Polyhedron ◽  
1986 ◽  
Vol 5 (11) ◽  
pp. 1741-1746 ◽  
Author(s):  
Gerard Lawless ◽  
Gerard McNally ◽  
A.R. Manning ◽  
Desmond Cunningham ◽  
Patrick McArdle
Keyword(s):  
1H Nmr ◽  
Nmr Spectra ◽  
1H Nmr Spectra ◽  
X Ray

Multinuclear Paramagnetic NMR Spectra and Solid State X-ray Crystallographic Characterization of Manganese(III) Schiff-Base Complexes

1997 ◽  
Vol 36 (22) ◽  
pp. 4968-4982 ◽  
Author(s):  
Yangzhen Ciringh ◽  
Scott W. Gordon-Wylie ◽  
Richard E. Norman ◽  
George R. Clark ◽  
Susan T. Weintraub ◽  
...  
Keyword(s):  
Schiff Base ◽  
Solid State ◽  
Nmr Spectra ◽  
Schiff Base Complexes ◽  
Paramagnetic Nmr ◽  
X Ray

6π-Tricarbonyl-Komplexe von Pyridin-Derivaten, Synthesen und Reaktionen / 6π-Tricarbonyl-Chromium Complexes of Pyridine Derivatives, Syntheses and Reactions

1984 ◽  
Vol 39 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Karl Dimroth ◽  
Rüdiger Thamm ◽  
Hans Kaletsch
Keyword(s):  
Hydrogen Atom ◽  
Phosphorus Atom ◽  
Nmr Spectra ◽  
Pyridine Derivatives ◽  
Chromium Complexes ◽  
X Ray ◽  
Chromium Hexacarbonyl ◽  
Allyl Rearrangement ◽  
Tricarbonylchromium Complexes ◽  
C Nmr

New 6π-tricarbonylchromiumpyrnftne complexes 5c and 5d could be synthesized from 2,6-di-rbutyl- and 2,4,6-tri-f-butylpyridines (3c and 3d) with chromium hexacarbonyl. They are characterized by their 1H and 13C NMR Spectra and their CO-frequencies which are rather similar to those of 6π-tricarbonylchromium-2,4 ,6-triphenyl [1] or 2,4,6-trw-butyl- [2] λ3-phosphorins. When 5d is reacted with lithiumphenyl, the phenyl residue adds to C-4, giving probably compound 7, which by methanolysis and allyl rearrangement of the hydrogen atom from position 4 to position 2 affords tricarbonylchromium-2,6-di-f-butyl-4-phenyl-1,2-dihydropyridine (8) in 56% yield. The 6π-tricarbonylchromium complexes of 2,4,6-triphenyl- or 2,4,6-tn-t-butyl-λ3-phosphorins react with lithiumorganic compounds by addition only to the phosphorus atom whose reaction with methyliodide lead to tricarbonylchromium-λ5-phosphorin-ylid complexes [2], 5 d is a well crystallized compound, the X-ray analysis of the first 6π-tricarbonylchromium pyridine derivate could be performed [3] and compared with the results of the X-ray analysis of 6π-tricarbonylchromiumx 2,4,6-triphenyl-λ3-phosphorin [4]

Organometallic oxides: preparation of the cluster [(η-C5Me5)Mo]4O7 by reduction of [(η-C5Me5)MoCl(O)]2(μ-O) or (η-C5Me5)MoCl2(O)

2000 ◽  
Vol 78 (3) ◽  
pp. 383-394
Author(s):  
Frank Bottomley ◽  
Victor Sanchez ◽  
Robert C Thompson ◽  
Olusola O Womiloju ◽  
Zhiqiang Xu
Keyword(s):  
Nmr Spectra ◽  
Chloroform Solution ◽  
X Ray Diffraction ◽  
Broad Resonance ◽  
Nmr Spectrum ◽  
X Ray ◽  
Temperature Range ◽  
H Nmr ◽  
Tributyltin Hydride ◽  
Effective Moment

Reduction of [(η-C5Me5)MoCl(O)]2(μ-O) or (η-C5Me5)MoCl2(O) with sodium or magnesium amalgam, magnesium turnings, or tributyltin hydride produced [(η-C5Me5)Mo]4O7, with [(η-C5Me5)Mo(O)(μ-O)]2 as a co-product. [(η-C5Me5)Mo]4O7 was characterized by X-ray diffraction, mass spectrometry, 1H NMR and IR spectroscopies, and magnetism. Crystals of [(η-C5Me5)Mo]4O7 contained a tetrahedral [(η-C5Me5)Mo]4 unit (Mo-Mo = 2.909 (3) Å) with the Mo4O7 core having the structure Mo4(μ2-O(b))3(µ2-O(c))3(µ3-O(a)) (3). Microcrystalline samples of [(η-C5Me5)Mo]4O7 were paramagnetic over the temperature range 2-300 K, with an effective moment of 1.26 μB at 300 K. [(η-C5Me5)Mo]4O7 was also paramagnetic in chloroform solution, over the temperature range 223-298 K, with an effective moment of 1.43 µB at 298 K. The 1H NMR spectrum showed a broad resonance at 16.3 ppm (Δν 1/2 = 113 Hz) and two narrow resonances at 1.89 ppm and 1.69 ppm (Δν 1/2 = 5 Hz). The magnetism and NMR spectra showed that [(η-C5Me5)Mo]4O7 existed in two forms which were in equilibrium in solution. One form was paramagnetic (S = 1), with the Mo4O7 core having the geometry 3, and the other was diamagnetic (S = 0), with the Mo4O7 core having the geometry 4.Key words: cluster, cyclopentadienyl, molybdenum, oxide, paramagnetism.

Nuclear magnetic resonance studies on the anions [M(SnCl3)5Cl]4− (M = Ru, Os) and [Ru(SnCl3)5(MeCN)]3−: the X-ray crystal structure of [N(C2H5)4]4[Ru(SnCl3)5Cl]

1982 ◽  
Vol 60 (11) ◽  
pp. 1304-1316 ◽  
Author(s):  
Louis J. Farrugia ◽  
Brian R. James ◽  
Claude R. Lassigne ◽  
Edward J. Wells
Keyword(s):  
Crystal Structure ◽  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Octahedral Geometry ◽  
Coupling Constants ◽  
Order Effects ◽  
Magnetic Resonance Studies ◽  
X Ray ◽  
Crystallographic Study

The octahedral anions [M(SnCl3)5Cl]4− (M = Ru, Os) have been fully characterized by 119Sn FT nmr spectroscopy. For M = Ru, 117Sn and 115Sn nmr spectra were also recorded, and an X-ray crystallographic study was carried out on the tetraethylammonium salt, isolated as a disolvate from acetonitrile. The Ru—Sn bond lengths indicate some degree of dπ–dπ interactions. The slight distortions from octahedral geometry are discussed in connection with the packing of the chlorine atoms. The Sn nmr spectra reveal the first observed coupling to a 99Ru nucleus (I = 5/2, 12.7% natural abundance), very large 2J(119Sn—117Sn) coupling constants, and the first observed second-order effects on a heteronuclear system. The octahedral anion [Ru(SnCl3)5(MeCN)]3− was also synthesized as the tetraethylammonium salt and characterized spectroscopically.

Sign in / Sign up

Export Citation Format

Share Document