Allylation of cobalt-co-ordinated cyclo-octatetraene by the [Fe{P(OMe)3}(NO)2(η3-allyl)]+cation: ring closure to 1,2,3,3a-tetrahydropentalenyl derivatives and the X-ray structure of [Co(η5-C8H8R)(η-C5Me5)][PF6][R = CH2C(Me)CH2]

1988 ◽  
pp. 1631-1636 ◽  
Author(s):  
Neil G. Connelly ◽  
Mark Gilbert ◽  
A. Guy Orpen ◽  
Jonathan M. White
Keyword(s):  
Ring Closure ◽  
X Ray ◽  
Allyl Cation

scholarly journals Stereoselective synthesis and transformation of pinane-based 2-amino-1,3-diols

2021 ◽  
Vol 17 ◽  
pp. 983-990
Author(s):  
Ákos Bajtel ◽  
Mounir Raji ◽  
Matti Haukka ◽  
Ferenc Fülöp ◽  
Zsolt Szakonyi
Keyword(s):  
Alkaline Hydrolysis ◽  
Stereoselective Synthesis ◽  
2D Nmr ◽  
Ring Closure ◽  
Spectroscopic Techniques ◽  
Reductive Alkylation ◽  
X Ray ◽  
Relative Stereochemistry ◽  
Hydrolysis Of

A library of pinane-based 2-amino-1,3-diols was synthesised in a stereoselective manner. Isopinocarveol prepared from (−)-α-pinene was converted into condensed oxazolidin-2-one in two steps by carbamate formation followed by a stereoselective aminohydroxylation process. The relative stereochemistry of the pinane-fused oxazolidin-2-one was determined by 2D NMR and X-ray spectroscopic techniques. The regioisomeric spiro-oxazolidin-2-one was prepared in a similar way starting from the commercially available (1R)-(−)-myrtenol (10). The reduction or alkaline hydrolysis of the oxazolidines, followed by reductive alkylation resulted in primary and secondary 2-amino-1,3-diols, which underwent a regioselective ring closure with formaldehyde or benzaldehyde delivering pinane-condensed oxazolidines. During the preparation of 2-phenyliminooxazolidine, an interesting ring–ring tautomerism was observed in CDCl3.

Chemistry of Polyhalogenated Nitrobutadienes, Part 9: Acyclic and Heterocyclic Nitroenamines and Nitroimines from 2-Nitroperchlorobuta-1,3-diene

2010 ◽  
Vol 65 (7) ◽  
pp. 843-860 ◽  
Author(s):  
Viktor A. Zapol’skii ◽  
Jan C. Namyslo ◽  
Mimoza Gjikaj ◽  
Dieter E. Kaufmann
Keyword(s):  
Single Crystal ◽  
Diffraction Analysis ◽  
Ring Closure ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
Substitution Pattern ◽  
X Ray

Various amino, diamino, aminothio, or benzotriazolo compounds derived from the exceedingly versatile 2-nitroperchlorobutadiene (1) gave structurally interesting and physiologically promising nitro-enamines, -imines, -amidines, and hydrazines as well as ring closure reaction products, e. g. pyrimidines and pyrazoles. Most of these reactions turned out to be highly selective with good to very good yields. The structure of the pyrazole precursor (E,E)-1-(benzotriazol-1-yl)-4,4-dichloro-3- (4-ethoxyphenylamino)-1-(4-ethoxyphenylimino)-2-nitrobut-2-ene (30), due to its exceptional substitution pattern, was evidenced by single-crystal X-ray diffraction analysis.

FTIR and XPS Studies of Polyimide/Metal Interface Formation

1989 ◽  
Vol 154 ◽  
Author(s):  
William C. Stewart ◽  
Jihperng Leu ◽  
Klavs F. Jensen
Keyword(s):  
Photoelectron Spectroscopy ◽  
Polymer Structure ◽  
Ring Closure ◽  
Metal Interface ◽  
Polyimide Films ◽  
Interface Formation ◽  
Xps Spectra ◽  
X Ray ◽  
Spectroscopy Studies ◽  
Thermal Stability Of

AbstractWe describe infrared and x-ray photoelectron spectroscopy studies of the interfaces formed when the PMDA/ODA polyamic acid is imidized on gold, chromium, and copper. Polyimide films ranging from 34 Å to 1328 Å are analyzed as part of these studies. The IR and XPS results indicate that the gold interacts very little with the polyimide, while copper produces significant changes in the IR and XPS spectra. At elevated cure temperatures passivated chromium also reacts with the polyimide. In structures with chromium and copper, the thermal stability of the polyimide at the interface is reduced from that of bulk polyimide. The data demonstrate that the metals interact with the polymer structure at the point where ring closure occurs to form the polyimide from polyarnic acid.

scholarly journals Synthesis and Structural Elucidation of the Acetylation Reaction’s Product(s) of the 2(1H)-Quinoxalinones Derived from L-Ascorbic Acid. X-Ray Molecular Structure of 3-(N-acetyl-2-naphthylhydrazono)-2,3-dihydro-2-acetoxyfuro[2,3-b]quinoxaline [1]

1992 ◽  
Vol 47 (6) ◽  
pp. 861-868 ◽  
Author(s):  
Adel Amer ◽  
Douglas M. Ho
Keyword(s):  
Molecular Structure ◽  
Ascorbic Acid ◽  
Acetic Anhydride ◽  
Structural Elucidation ◽  
Ring Closure ◽  
The Other ◽  
High Yield ◽  
X Ray ◽  
Reaction Condition ◽  
Tricyclic Compound

Acetylation reaction’s product(s) of 3-[L-threo-2,3,4-trihydroxy-1-(2-naphthylhydrazono)-butyl]quinoxalin-2(1H)-one (2b) were found to be dependent on the reaction condition. While the tri-O-acetyl (3b) was isolated in high yield from 2b under the action of acetic anhydride/pyridine mixture, compounds 4b and 5b as well as trace of 3b were obtained when 2b was heated in acetic anhydride. On the other hand, 3-[1-(2-naphthylhydrazono)-glyoxal-1-yl]quinoxalin-2(1H)-one (7) underwent ring closure and afforded the condensed tricyclic compound 8 under the action of acetic anhydride/pyridine mixture.

scholarly journals Design, Synthesis, and Evaluation of X-ray Crystal Structure, Biological Activities, DFT Calculations, and Molecular Docking of Phenyl Imidazolidin-2-One Derivatives

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 713
Author(s):  
Xile Deng ◽  
Can Jin ◽  
Yong Xie ◽  
Junbo Gao ◽  
Xiaomao Zhou
Keyword(s):  
Molecular Docking ◽  
Dft Calculations ◽  
Insecticidal Activity ◽  
Plutella Xylostella ◽  
Density Functional ◽  
Biological Activities ◽  
Phytophthora Sojae ◽  
Ring Closure ◽  
Binding Modes ◽  
X Ray

Eight phenyl imidazolinone derivatives were synthesized from N2-(2,4-dimethylphenyl)-N1-methyformamidine (DPMF) via scaffold-hopping method using the ring-closure approach. The prepared compounds were verified using 1H and 13C NMR and HRMS spectroscopies. The structure of compound 3c was confirmed by single-crystal X-ray diffraction analysis. The mean plane of the phenyl and imidazolinone moieties was almost coplanar with an angle of 8.85(4)°. In the crystal, molecules were interlinked with intermolecular hydrogen bonds (N–H···O and C–H···O), generating a network structure. Additionally, compound 3f displayed the highest insecticidal activity (86.7%) against Plutella xylostella at 600 mg/L, which was significantly higher than the insecticidal activity (23.0%) of DPMF. Also, compound 3d displayed good fungicidal activities against Phytophthora capsici, Phytophthora sojae, and Phytophthora infestans. Density functional theory (DFT) calculations were performed to explain the insecticidal and fungicidal activities of phenyl imidazolidin-2-one derivatives, especially potent compounds 3f and 3d. Moreover, the binding modes of compounds 3a–h and DPMF against octopamine receptor of Plutella xylostella were studied by homology modeling and molecular docking. Therefore, a preliminary structure–activity relationship (SAR) was derived and discussed. These results encourage the exploration of novel insecticides and fungicides based on DPMF.

X-Ray Determination of Strain Distribution in Inconel Alloy 600 C-Ring

1988 ◽  
Vol 142 ◽  
Author(s):  
C. F. Lo ◽  
H. Kamide ◽  
G. Feng ◽  
W. E. Mayo ◽  
S. Weissmann
Keyword(s):  
Surface Layer ◽  
Strain Distribution ◽  
Deformation Process ◽  
Ring Closure ◽  
Alloy 600 ◽  
Plastic Strains ◽  
Rocking Curve ◽  
Inconel Alloy ◽  
X Ray ◽  
Nominal Strain

AbstractAn Inconel Alloy 600 C-ring was subjected to various strain levels and the deformation process was monitored by a Computer Aided Rocking Curve Analyzer (CARCA). A large grain population was sampled, and the calibration curve of average rocking curve halfwidth of the individual grains relating to the nominal strain was established. The strain distribution as a function of the angular position along the peripheral surface layer and layers at different depth distance was obtained. Up to C-ring closure at the nominal strain of 3.3% at the apex, the induced plastic strains were confined to a surface layer of 30–40 gm in depth.The largest strain and strain gradients below the surface occurred at the apex and near apex region. The extent and the spread of microdeformation inhomogeneity increased with applied strain. At ring closure some grains exhibited large plastic strains while others exhibited only small plastic strains or were not affected by the deformation process at all. These experimental results were not in agreement with the current theoretical understanding of the deformation of C-ring since these theories did not take shape changes into account. When such changes were included, good agreement on the angular strain dependence for the apex and near apex region were achieved between experiment and theory. It was concluded that the CARCA X-ray method can be a useful research tool in aiding and guiding mathematical modeling of non-linear inelastic behavior of solids by disclosing important microstructural and micromechanical aspects.

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