Sterically Crowded Heterocycles. I. Molecular Structure of 3-Chain Substituted 2-Phenylimidazo[1,2-a]pyridinium Salts

1994 ◽  
Vol 59 (12) ◽  
pp. 2677-2690 ◽  
Author(s):  
Stanislav Böhm ◽  
Richard Kubík ◽  
Martin Hradilek ◽  
Jan Němeček ◽  
Michal Hušák ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Nmr Spectra ◽  
Molecular Structures ◽  
Pyridinium Salts ◽  
Protonation Site ◽  
X Ray ◽  
H Nmr ◽  
C Nmr ◽  
Pyridinium Perchlorate

2-Phenyl-3-[(Z)-1,3-diphenyl-3-oxopropenyl]imidazo[1,2-a]pyridine (I) was converted to corresponding 1-alkyl-2-phenyl-3-[(Z)-1,3-diphenyl-3-oxopropenyl]imidazo[1,2-a]pyridinium salts III - VI and 2-phenyl- 3-[(Z)-1,3-diphenyl-3-oxopropenyl]imidazo[1,2-a]pyridinium perchlorate (VII). The protonation site is discussed in terms of calculated molecular energies of alternative cations. The X-ray structure analyses of enone I and its quaternary periodide III are reported and compared with the PM3 molecular optimizations. 1H NMR and 13C NMR spectra reveal well changes of molecular structures caused by the transformation of the base I into salts III - VII.

Synthesis, characterization, and the molecular structures of two new kinds of stilbene

2006 ◽  
Vol 84 (6) ◽  
pp. 867-873 ◽  
Author(s):  
Yan-Hong Liu ◽  
Tong-Lai Zhang ◽  
Jian-Guo Zhang ◽  
Li Yang ◽  
Jin-Yu Guo ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Thermal Decomposition ◽  
High Heat ◽  
Molecular Structures ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Decomposition Processes ◽  
Ft Ir ◽  
C Nmr

We report in this study the synthesis, crystal culture, and single-crystal X-ray crystallography of two new kinds of double stilbene, which were readily prepared from trinitro-p-xylene and p-tolualdehyde in the presence of piperidine. We found that these triclinic crystals belong to the space group P-1. These compounds were also investigated using FT-IR, 1H NMR, 13C NMR, and MS spectroscopy techniques. The thermal decomposition processes of the compounds were tested by DSC and TG-DTG at a heating rate of 10  C/min. These results indicate that the compounds have high heat-resistant stability.Key words: polynitrostilbene, molecular structure, thermal decomposition.

scholarly journals Reactions of 3-(p-substituted-phenyl)-5-chloromethyl-1,2,4-oxadiazoles with KCN leading to acetonitriles and alkanes via a non-reductive decyanation pathway

2018 ◽  
Vol 14 ◽  
pp. 3011-3017
Author(s):  
Akın Sağırlı ◽  
Yaşar Dürüst
Keyword(s):  
Nmr Spectra ◽  
2D Nmr ◽  
Synthetic Route ◽  
X Ray ◽  
H Nmr ◽  
2D Nmr Spectra ◽  
Tof Ms ◽  
C Nmr

The present work describes an unfamiliar reaction of 5-(chloromethyl)-3-substituted-phenyl-1,2,4-oxadiazoles with KCN affording trisubstituted 1,2,4-oxadiazol-5-ylacetonitriles and their parent alkanes, namely, 1,2,3-trisubstituted-1,2,4-oxadiazol-5-ylpropanes. To the best of our knowledge, the current synthetic route leading to decyanated products will be the first in terms of a decyanation process which allows the transformation of trisubstituted acetonitriles into alkanes by the incorporation of KCN with the association of in situ-formed HCN and most likely through the extrusion of cyanogen which could not be detected or isolated. In addition, the plausible mechanisms were proposed for both transformations. The structures of the title compounds were identified by means of IR, 1H NMR, 13C NMR, 2D NMR spectra, TOF–MS and X-ray measurements.

scholarly journals New Synthetic Routes for 1-Benzyl-1,4,7,10-tetraazacyclododecane and 1,4,7,10-Tetraazacyclododecane-1-acetic Acid Ethyl Ester, Important Starting Materials for Metal-coded DOTA-Based Affinity Tags

2007 ◽  
Vol 62 (3) ◽  
pp. 397-406 ◽  
Author(s):  
Stephan W. Kohl ◽  
Katharina Kuse ◽  
Markus Hummert ◽  
Herbert Schumann ◽  
Clemens Mügge ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Ethyl Ester ◽  
Nmr Spectra ◽  
Acid Ethyl Ester ◽  
Affinity Tags ◽  
X Ray ◽  
H Nmr ◽  
Synthetic Routes ◽  
New Compounds ◽  
C Nmr

Two improved routes to synthesize 1-benzyl-1,4,7,10-tetraazacyclododecane (6) and 1,4,7,10- tetraazacyclododecane-1-acetic acid ethyl ester (11) are described as well as the synthesis of 1-{2-[4-(maleimido-N-propylacetamidobutyl)amino]-2-oxoethyl}-1,4,7,10-tetraazacyclododecane- 4,7,10-triacetic acid (17) and its Y, Ho, Tm, and Lu complexes. The 1H and 13C NMR spectra of the new compounds as well as the single crystal X-ray structure analyses of the intermediates 4-benzyl-1,7-bis(p-toluenesulfonyl)diethylenetriamine (3) and 1,4,7-tris(p-toluenesulfonyl)diethylenetriamine (7) are reported and discussed. The rare earth complexes of 17 have been characterized by 1H NMR spectroscopy and MALDI-TOF mass spectrometry.

β-Hydroxydithiozimtsäurederivate als Liganden. Synthese und Charakterisierung neuartiger 1,1-Ethendithiolato- und O,S-Chelatkomplexe / Derivatives of β -Hydroxydithiocinnamic Acids as Ligands. Syntheses and Characterisation of Novel 1,1-Ethenedithiolato and O,S-Chelate Complexes

2007 ◽  
Vol 62 (3) ◽  
pp. 475-482 ◽  
Author(s):  
Karsten Schubert ◽  
Helmar Görls ◽  
Wolfgang Weigand
Keyword(s):  
Bidentate Ligand ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Chelate Complexes ◽  
X Ray ◽  
H Nmr ◽  
Hexyl Ester ◽  
Elemental Analyses ◽  
Derivatives Of ◽  
C Nmr

Starting from 4-bromoacetophenone 1, the 4-bromo-β -hydroxydithiocinnamic acid 2 and the 4-bromo-β -hydroxydithiocinnamic acid hexyl ester 3 were prepared using carbon disulfide and potassium-tert-butylate as a base. Acting as a ligand, the acid gives 1,1-ethenedithiolato complexes with (Ph3P)2Pt(II) (4a), (Et3P)2Pt(II) (4b), dppePt(II) (4c), (Ph3P)2Pd(II) (4d), dppePd(II) (4e), and dppeNi(II) (4f). In contrast to the acid, the deprotonated ester 3 forms a monoanionic bidentate ligand. [O,S] Complexes of Pt(II) (5a), Pd(II) (5b) and Ni(II) (5c) were obtained. All complexes have been fully characterised using 1H NMR, 13C NMR and 31P NMR spectroscopy, mass spectrometry, infrared spectroscopy and elemental analyses. The molecular structures of the complexes 4b and 5a - 5c were determined by X-ray diffraction analyses.

On the chemistry and high field nuclear magnetic resonance spectroscopy of rapamycin

1980 ◽  
Vol 58 (6) ◽  
pp. 579-590 ◽  
Author(s):  
John A. Findlay ◽  
Lajos Radics
Keyword(s):  
High Field ◽  
Nmr Spectra ◽  
Resonance Spectroscopy ◽  
X Ray ◽  
Conformational Isomers ◽  
H Nmr ◽  
Neutral Compounds ◽  
Complete Assignment ◽  
Hydrolysis Of ◽  
C Nmr

Base catalysed hydrolysis of rapamycin (C51H79NO13) affords six neutral compounds identified by chemical and spectroscopic means as 2a, 3b, 3d, 5, 2,4-dimethylphenol, and L(−)-piperidine-2-carboxylic acid 6, and whose generation has been plausibly rationalized. These findings as well as detailed analyses of 13C nmr and 1H nmr spectra provide independent corroboration of the X-ray derived rapamycin crystal structure 1. Structurally homogeneous in the solid state, rapamycin is found to occur in solutions as a mixture of two conformational isomers (approximately 4:1). Through nearly complete assignment of the high field 1H (400 MHz) and 13C (100.6 MHz) nmr spectra, the isomerism is shown to be associated with trans–cis rotation of an amidic bond within the 31-membered macrolide ring. The predominant form corresponds to the conformer portrayed by X-ray analysis.

Preparation of pyridinium salts of 2-furane derivatives

1984 ◽  
Vol 49 (11) ◽  
pp. 2485-2491 ◽  
Author(s):  
Miroslav Kríž ◽  
Jaroslav Kováč ◽  
Vladimír Mlynárik
Keyword(s):  
Nucleophilic Substitution ◽  
Substitution Reaction ◽  
Nmr Spectra ◽  
Nucleophilic Substitution Reaction ◽  
Pyridinium Salts ◽  
H Nmr ◽  
C Nmr

Pyridinium salts have been prepared by nucleophilic substitution reaction of 5-halogeno-2-furane derivatives with pyridine and its 3- and 4-substituted derivatives, where R = 3-methyl, 3-ethyl, 3-amino, 3-methoxycarbonyl, 3-aminocarbonyl, 4-amino, 4-aminocarbonyl, 4-phenoxy, and 3,4-dimethyl, and structure of the derivatives prepared has been confirmed by their 1H NMR and 13C NMR spectra.

On Attempts to Synthesize Lanthanide Complexes of the Dianionic Fluorenyl-alkoxo Ligand [C13H8-cyclo-C6H10-O]2-. Crystal Structure of (C13H9-cyclo-C6H10-O)LaI2(DME)2

2003 ◽  
Vol 58 (5) ◽  
pp. 389-394 ◽  
Author(s):  
Alexander A. Trifonov ◽  
Mikhail N. Bochkarev ◽  
Herbert Schumann ◽  
Sebastian Dechert
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Ir Spectra ◽  
Single Crystal ◽  
Lanthanide Complexes ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Elemental Analyses ◽  
C Nmr

Racemic trans-2-(9(H)-fluoren-9-yl)cyclohexanol, C13H9-cyclo-C6H10-OH (1), reacts with two equivalents of potassium naphthalenide in THF to give the dipotassium salt [C13H8-cyclo-C6H10-O]- K2(THF) (2). Recrystallization of 2 from pyridine affords the solvent free salt [C13H8-cyclo-C6H10- O]K2 (3). The reactions of LaI3(THF)4 with one equivalent of 2 or of YbI2(THF)2 with equimolar amounts of 2 produce the alkoxolanthanum diiodide (C13H9-cyclo-C6H10-O)LaI2(DME)2 (4) and the ytterbium dialkoxide (C13H9-cyclo-C6H10-O)2Yb(THF)0.5(5), respectively. [(Me3Si)2N]3Y reacts with three equivalents of 1 with elimination of hexamethyldisilazane and formation of the yttrium trialkoxide (C13H9-cyclo-C6H10-O)3Y (6). The compounds 2 to 5 were characterized by elemental analyses, 1H NMR, 13C NMR and IR spectra. The molecular structure of 4 was determined by single crystal X-ray diffraction.

Binuclear Fulvalene and Bis(cyclopentadienyl)methane Halfsandwich Complexes of Manganese and Rhenium Containing Tetrahydrothiophene Ligands. X-Ray Structure Analysis of {(CO)2Mn[C5H4-C5H4]Mn(CO)2}(μ-SC4H8)

1993 ◽  
Vol 48 (2) ◽  
pp. 161-170 ◽  
Author(s):  
Max Herberhold ◽  
Martin Biersack ◽  
Thomas E. Bitterwolf ◽  
Arnold L. Rheingold
Keyword(s):  
Molecular Structure ◽  
Ir Spectra ◽  
Structure Analysis ◽  
Nmr Spectra ◽  
X Ray ◽  
Carbonyl Ligands ◽  
Tetrahydrofuran Solution ◽  
C Nmr

AbstractThe photo-induced substitution of carbonyl ligands in the binuclear cyclopentadienyl-type complexes (CO)3M[C5H4(CH2)nC5H4]M(CO)3 (n = 0 (fulvalene), M = Mn (1) and Re (2); n = 1 (bis(cyclopentadienyl)methane), M = Mn (3) and Re (4)) has been studied in the presence of tetrahydrothiophene, SC4H8 (tht). Photodecarbonylation of 1 - 4 in tetrahydrofuran solution leads to solvent-stabilized intermediates which react with tht in the dark to give monosubstituted derivatives (CO)3M[C5H4(CH2)nC5H4]M(CO)2(tht) (1a - 4a). In the case of M = Mn, thtbridged compounds {(CO)2Mn[C5H4(CH2)nC5H4]Mn(CO)2}(μ-tht) (n = 0 (1b) and n = 1 (3b)) are also obtained which are the exclusive products of the photolysis of 1 and 3 in benzene in the presence of tht. Photodecarbonylation of 1 - 4 in neat tetrahydrothiophene produces disubstituted derivatives in the case of manganese, (tht)(CO)2Mn[C5H4(CH2)nC5H4]Mn(CO)2(tht) (n = 0 (1c) and n = 1 (3c)), whereas only the monosubstituted complexes 2a and 4a could be isolated in the case of rhenium. The molecular structure of the tht-bridged fulvalene complex 1b has been determined by an X-ray structure analysis. A special reaction of dimethyl disulfane with the photolyzed tetrahydrofuran solution of 2 leads to the bis(methylthiolato) compound (CO)3Re[C5H4- C5H4]Re(CO)(SMe)2 (5). The new complexes were characterized by their IR spectra v(CO) and their 1H and 13C NMR spectra.

Triferrocenylborane – Molecular Structure in Solution and in the Solid State

1995 ◽  
Vol 50 (2) ◽  
pp. 201-204 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Udo Dörfler ◽  
Wolfgang Milius ◽  
Max Herberhold
Keyword(s):  
Molecular Structure ◽  
Solid State ◽  
Low Temperature ◽  
Single Crystal ◽  
Nmr Spectra ◽  
The Other ◽  
X Ray ◽  
Single Diastereomer ◽  
Structure In Solution ◽  
C Nmr

According to a single crystal X-ray structure determination all three ferrocenyl substituents of triferrocenylborane (1) adopt the same orientation with respect to the BC3-plane [P21/c monoclinic; Z = 4; a = 1353.5(3), b = 1695.6(3), c = 1056.4(2) pm, β = 109.27(3)°]. The simulated X-ray powder pattern of the single crystal is identical with the powder diagram of a macroscopic sample, indicating the presence of a single diastereomer (1a) in the solid state. However, at low temperature (< - 95 °C) in solution, the 13C NMR spectra suggest the presence of the second diastereomer (1b) in which one ferrocenyl group is oriented opposite to the other two with respect to the central BC3-plane.

Kristallstruktur und spektroskopische Untersuchung von Mg(GeMe3)2 · 2 DME / Crystal Structure and Spectroscopic Study of Mg(GeMe3)2 · 2 DME

1984 ◽  
Vol 39 (7) ◽  
pp. 855-860 ◽  
Author(s):  
Lutz Rösch ◽  
Carl Krüger ◽  
A .-P. Chiang
Keyword(s):  
Crystal Structure ◽  
Spectroscopic Study ◽  
Nmr Spectra ◽  
X Ray ◽  
H Nmr ◽  
Magnesium Compound ◽  
C Nmr

Mg(GeMe3)2 · 2 DME is synthesized by reaction of Hg(GeMe3)2 with magnesium in 1 ,2 -- dimethoxyethane. The X-ray structure, IR, Raman, 1H NMR , and 13C NMR spectra of this first organogermyl magnesium compound are reported.

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