Hydrogenation of cinnamyl methyl ether and allylbenzene on palladium catalysts

1987 ◽  
Vol 52 (4) ◽  
pp. 1015-1020 ◽  
Author(s):  
Libor Červený ◽  
Ivo Paseka ◽  
Eva Fialová ◽  
Vlastimil Růžička
Keyword(s):  
Double Bond ◽  
Solvent Effect ◽  
Benzene Ring ◽  
Methyl Ether ◽  
Atmospheric Pressure ◽  
Palladium Catalysts ◽  
Polar Medium ◽  
Adsorbed Molecules ◽  
Ionic Nature ◽  
Bond Splitting

The hydrogenation of cinnamyl methyl ether and allylbenzene in hexane and acetone at 20 °C and atmospheric pressure of hydrogen has been studied on eight palladium catalysts. The hydrogenation of cinnamyl methyl ether is accompanied by C-O bond splitting giving rise to propylbenzene and methanol, the hydrogenation of allylbenzene is associated with the isomerization of the double bond resulting in its conjugation with the benzene ring. A marked solvent effect on the selectivity of hydrogenation of cinnamyl methyl ether has been observed and ascribed to the effect of solvated protons on the adsorbed molecules of the ether which is promoted by polar medium. The solvent effect on the isomerization of allylbenzene during the hydrogenation is little pronounced, which suggests that this reaction is not of ionic nature.

scholarly journals Crystal structure of (3E)-3-(2,4-dinitrophenoxymethyl)-4-phenylbut-3-en-2-one

2014 ◽  
Vol 70 (9) ◽  
pp. o1051-o1052 ◽  
Author(s):  
Ignez Caracelli ◽  
Stella H. Maganhi ◽  
Paulo J. S. Moran ◽  
Bruno R. S. de Paula ◽  
Felix N. Delling ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Double Bond ◽  
Nitro Group ◽  
Benzene Ring ◽  
Torsion Angle ◽  
Title Compound ◽  
Phenyl Ring ◽  
Aromatic Rings ◽  
Compound C ◽  
The One

In the title compound, C17H14N2O6, the conformation about the C=C double bond [1.345 (2) Å] isE, with the ketone moiety almost coplanar [C—C—C—C torsion angle = 9.5 (2)°] along with the phenyl ring [C—C—C—C = 5.9 (2)°]. The aromatic rings are almost perpendicular to each other [dihedral angle = 86.66 (7)°]. The 4-nitro moiety is approximately coplanar with the benzene ring to which it is attached [O—N—C—C = 4.2 (2)°], whereas the one in theorthoposition is twisted [O—N—C—C = 138.28 (13)°]. The molecules associateviaC—H...O interactions, involving both O atoms from the 2-nitro group, to form a helical supramolecular chain along [010]. Nitro–nitro N...O interactions [2.8461 (19) Å] connect the chains into layers that stack along [001].

N.M.R. STUDIES OF BRIDGED RING SYSTEMS: II. UNUSUAL MAGNETIC DESHIELDING EFFECT ON THE BRIDGE METHYLENES OF NORBORNADIENE AND BENZONORBORNADIENE

1964 ◽  
Vol 42 (4) ◽  
pp. 926-933 ◽  
Author(s):  
K. Tori ◽  
Y. Hata ◽  
R. Muneyuki ◽  
Y. Takano ◽  
T. Tsuji ◽  
...  
Keyword(s):  
Double Bond ◽  
Benzene Ring ◽  
Chemical Shifts ◽  
Electron System ◽  
Electron Systems ◽  
Double Bonds ◽  
Diamagnetic Anisotropy ◽  
Anisotropy Effect ◽  
Transannular Interaction ◽  
Olefinic Double Bond

Proton magnetic resonance spectra of some norbornane derivatives having double bonds and (or) a benzene ring in the skeleton were studied. Differences in the chemical shifts between the bridge methylenes of norbornene and benzonorbornene and that of norbornane result from the diamagnetic anisotropy effect of a double bond or a benzene ring being in good agreement with the values calculated theoretically. However, in the norbornadiene derivatives which have two double bonds or one olefinic double bond with a benzene ring in a part of the skeleton, the signals of their bridge methylenes show extraordinarily larger downfield shifts by about 0.8 p.p.m. than those expected from the additive shielding due to each π-electron system. This anomaly is not observed in bicyclo[2.2.2]octane ring series. A large transannular interaction between two π-electron systems in that system would be a major contribution to the above anomaly.

Solvent effect on the radical addition reaction to double bond: Experimental and quantum chemical investigations

2005 ◽  
Vol 415 (4-6) ◽  
pp. 202-205 ◽  
Author(s):  
Jacques Lalevée ◽  
Xavier Allonas ◽  
Jean Pierre Fouassier ◽  
Daniel Rinaldi ◽  
Manuel F. Ruiz Lopez ◽  
...  
Keyword(s):  
Double Bond ◽  
Solvent Effect ◽  
Quantum Chemical ◽  
Addition Reaction ◽  
Radical Addition

scholarly journals Crystal structure determination of two pyridine derivatives: 4-[(E)-2-(4-methoxyphenyl)ethenyl]-1-methylpyridin-1-ium hexafluoro-λ6-phosphane and 4-[(E)-2-[4-(dimethylamino)phenyl]ethenyl]-1-phenyl-1λ5-pyridin-1-ylium hexafluoro-λ6-phosphane

2019 ◽  
Vol 75 (2) ◽  
pp. 288-291
Author(s):  
J. Arul Martin Mani ◽  
M. Mercina ◽  
S. Antony Inglebert ◽  
P. Narayanan ◽  
V. Joseph ◽  
...  
Keyword(s):  
Double Bond ◽  
Benzene Ring ◽  
Pyridine Ring ◽  
Crystal Packing ◽  
Pyridine Derivatives ◽  
Compound I ◽  
Π Interactions ◽  
Molecular Salts ◽  
Compound Ii

The title molecular salts, C16H16NO+·PF6 −, (I), and C21H21N2 +·PF6 −, (II), are pyridine derivatives. In compound (I), the cation comprises a methyl N-substituted pyridine ring and a methoxy-substituted benzene ring connected by a C=C double bond. The F atoms of the PF6 − anion are disordered over two sets of sites with refined occupancy factors of 0.614 (7):0.386 (7). In compound (II), the cation comprises a pyridine ring attached to unsubstituted phenyl ring and a dimethylaniline ring, which are connected by a C=C double bond. The anion is PF6 −. In both salts, the cation adopts an E configuration with respect to the C=C bond. The pyridine ring makes a dihedral angle of 9.86 (12)° with the methoxy-substituted benzene ring in compound (I) and 11.2 (3)° with the dimethylamine-substituted benzene ring in compound (II). In compound (I), the crystal packing is stabilized by weak C—H...F intermolecular interactions which result in R 4 3(14) ring motifs, forming molecular sheets running parallel to (\overline{1}03). These are further stabilized by weak P—F...π interactions. In compound (II), the crystal packing is stabilized by C—H...F interactions, which result in R 6 6(40) ring motifs, forming molecular sheets running parallel to (101) and these are further connected by π–π interactions.

The UV Photolysis (λ = 185 nm) of Liquid Methyl n-Propyl Ether

1975 ◽  
Vol 30 (5-6) ◽  
pp. 399-403 ◽  
Author(s):  
Heinz-Peter Schuchmann ◽  
Clemens von Sonntag
Keyword(s):  
Quantum Yield ◽  
Methyl Ether ◽  
Quantum Yields ◽  
Uv Photolysis ◽  
Photochemical Processes ◽  
Butyl Methyl Ether ◽  
Bond Splitting

The main products of the 185 nm photolysis of liquid methyl n-propyl ether (quantum yields in parentheses) are n-propanol (0.70), methane (0.29), sec-butyl methyl ether (0.20), methanol (0.16), propionaldehyde (0.13), 3,4-dimethoxyhexane (0.09), ethane (0.08), and ethyl n-propyl ether (0.08). The quantum yields of further 24 minor products have been measured. The quantum yield of the sum of primary photochemical processes, the main ones of which are the homolytic scissions of the C–O bonds (reactions i and ii), is close to unity.Reaction (i) is favoured over reaction (ii) by nearly a factor of five. The elimination of molecular methane (iii) is the only other process of importance. C–H and C–C bond splitting is marginal.

scholarly journals Crystal structure and Hirshfeld surface analysis of a chalcone derivative: (E)-3-(4-fluorophenyl)-1-(4-nitrophenyl)prop-2-en-1-one

2019 ◽  
Vol 75 (1) ◽  
pp. 53-57
Author(s):  
Qin Ai Wong ◽  
Tze Shyang Chia ◽  
Huey Chong Kwong ◽  
C. S. Chidan Kumar ◽  
Ching Kheng Quah ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bond ◽  
Double Bond ◽  
Benzene Ring ◽  
Surface Analysis ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Chalcone Derivative ◽  
Centroid Distance

The molecular structure of the title chalcone derivative, C15H10FNO3, is nearly planar and the molecule adopts a trans configuration with respect to the C=C double bond. The nitro group is nearly coplanar with the attached benzene ring, which is nearly parallel to the second benzene ring. In the crystal, molecules are connected by pairs of weak intermolecular C—H...O hydrogen bonds into inversion dimers. The dimers are further linked by another C—H...O hydrogen bond and a C—H...F hydrogen bond into sheets parallel to (104). π–π interactions occur between the sheets, with a centroid–centroid distance of 3.8860 (11) Å. Hirshfeld surface analysis was used to investigate and quantify the intermolecular interactions.

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