Synthesis of substituted β-styrylmalonates by sequential isomerization of 2-arylcyclopropane-1,1-dicarboxylates and (2-arylethylidene)malonates

Synthesis ◽  
2021 ◽  
Author(s):  
Denis Dmitrievich Borisov ◽  
Grigorii R. Chermashentsev ◽  
Roman A. Novikov ◽  
Yury V. Tomilov
Keyword(s):  
Double Bond ◽  
Aromatic Ring ◽  
Gallium Trichloride

A method has been developed for the synthesis of substituted β-styrylmalonates by conversion of 2-arylcyclopropane-1,1-dicarboxylates (ACDC) in the presence of gallium trichloride into the corresponding 1,2-zwitterionic intermediates or (2-arylethylidene)malonates, followed by treatment with pyridine at rt leading to an isomerization of the emerging double bond. This method allows one to expand these reactions to include ACDC with acceptor substituents at the aromatic ring.

The General Dienol: Benzene Rearrangement of Ring a of the Steroids

2005 ◽  
Vol 2005 (3) ◽  
pp. 141-146 ◽  
Author(s):  
James R. Hanson
Keyword(s):  
Double Bond ◽  
Aromatic Ring ◽  
Ion Source ◽  
Carbonium Ion ◽  
Wide Range

The dienol: benzene type of rearrangement of steroids, to form compounds with an aromatic ring A, occurs under acid-catalysed conditions with a wide range of substrates containing two double bond equivalents and a carbonium ion source on rings A and B.

Diethyl 3-methyl-5-(triphenylphosphoranyleneamino)thiophene-2,4-dicarboxylate

2007 ◽  
Vol 63 (11) ◽  
pp. o4466-o4466
Author(s):  
Yuan-Hong Jiao ◽  
Qian Zhang ◽  
Seik Weng Ng
Keyword(s):  
Double Bond ◽  
Aromatic Ring ◽  
The Other ◽  
Phenyl Rings

The title iminophosphorane, C29H28NO4PS, a thiophene compound with the sterically crowded –N=P(C6H5)3 substituent in the α-position of the aromatic ring, features an N =P double bond of length 1.572 (3) Å. One of the phenyl rings is coplanar with the plane of the three ipso-C atoms, whereas the other two are approximately orthogonal.

scholarly journals Intramolecular 1,5-S...N σ-hole interaction in (E)-N′-(pyridin-4-ylmethylidene)thiophene-2-carbohydrazide

2020 ◽  
Vol 76 (4) ◽  
pp. 557-561
Author(s):  
Valeri V. Mossine ◽  
Steven P. Kelley ◽  
Thomas P. Mawhinney
Keyword(s):  
Crystal Structure ◽  
Double Bond ◽  
Hydrogen Bonds ◽  
Aromatic Ring ◽  
Intermolecular Interactions ◽  
Title Compound ◽  
Molecular Conformation ◽  
Monoclinic Space Group ◽  
Compound C ◽  
Hole Interaction

The title compound, C11H9N3OS, (I), crystallizes in the monoclinic space group P21/n. The molecular conformation is nearly planar and features an intramolecular chalcogen bond between the thiophene S and the imine N atoms. Within the crystal, the strongest interactions between molecules are the N—H...O hydrogen bonds, which organize them into inversion dimers. The dimers are linked through short C—H...N contacts and are stacked into layers propagating in the (001) plane. The crystal structure features π–π stacking between the pyridine aromatic ring and the azomethine double bond. The calculated energies of pairwise intermolecular interactions within the stacks are considerably larger than those found for the interactions between the layers.

scholarly journals On the Importance of the Aromatic Ring Parameter in Studies of the Solvolyses of Cinnamyl and Cinnamoyl Halides

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Malcolm J. D'Souza ◽  
Anthony M. Darrington ◽  
Dennis N. Kevill
Keyword(s):  
Double Bond ◽  
Aromatic Ring ◽  
Alkyl Halides ◽  
Aromatic Rings ◽  
Cinnamoyl Chloride ◽  
Recent Claim

In solvolysis studies using Grunwald-Winstein plots, dispersions were observed for substrates with aromatic rings at the α-carbon. Several examples for the unimolecular solvolysis of monoaryl benzylic derivatives and related diaryl- or naphthyl-substituted derivatives have now been reported, where the application of the aromatic ring parameter (I) removes this dispersion. A recent claim suggesting the presence of an appreciable nucleophilic component to the I scale has now been shown, in a review of the solvolysis of highly-hindered alkyl halides, to be unlikely to be correct. Attention is now focused on the application of the hI term for the solvolysis of compounds containing a double bond in the vicinity of any developing carbocation. Available specific rates of solvolysis (plus some new values) at 25°C of cinnamyl chloride, cinnamyl bromide, cinnamoyl chloride, p-chlorocinnamoyl chloride, and p-nitrocinnamoyl chloride are analyzed using the simple and extended (including the hI term) Grunwald-Winstein equations.

Adsorption of 2-vinyl thiophene on Si(100)2 × 1: A van Der Waals corrected DFT study

2015 ◽  
Vol 14 (02) ◽  
pp. 1550011 ◽  
Author(s):  
Marilena Carbone
Keyword(s):  
Density Functional Theory ◽  
Double Bond ◽  
Aromatic Ring ◽  
Density Functional ◽  
Monomer Unit ◽  
Van Der Waals ◽  
Transition States ◽  
Dft Study ◽  
Functional Theory ◽  
Transition Energies

Oligo- and polythiophenes on surfaces play a fundamental role in building molecular circuits and organic-based electronics and may be assembled via interaction of the monomer units with the surface. In this framework, the nature of interaction of 2-vinyl thiophene (2VTP), a conjugated heteroaromatic monomer unit, with the Si (100) surface was studied by means of density functional theory (DFT). In particular, structural optimizations were performed comparing the effects of the inclusion of van der Waals (VdW) forces. It came out that the adsorption through the double bond is energetically favored, if VdW forces are included, whereas the adsorption through both aromatic ring and double bond simultaneously is more stable, if they are excluded. Physisorbed states were singled out and the barriers between two of them and the corresponding chemisorbed states were calculated along with the imaginary frequencies of the transition states. Also the transition energies have different values if the VdW forces are included.

Neutral hyperconjugation and one-bond couplings between heavy atoms

2000 ◽  
Vol 78 (11) ◽  
pp. 1441-1444 ◽  
Author(s):  
Joseph B Lambert ◽  
Catherine E Shawl ◽  
Ernani Basso
Keyword(s):  
Double Bond ◽  
Aromatic Ring ◽  
Bond Order ◽  
Coupling Constant ◽  
Heavy Atoms ◽  
Two Systems ◽  
The Relationship

The relationship has been examined between bond order and one-bond couplings involving heavy atoms, as modulated by neutral hyperconjugation. Two systems have been studied in which either an aromatic ring or a double bond can influence, through hyperconjugation, the α and β bonds (respectively, Ci—C and Ci—M in =C-C-M). Hyperconjugation may be modulated by substituents on the aromatic ring or double bond or by placement of different atoms (M = C, Si, Ge, or Sn) at the β position. The α bond exhibits no relationship between coupling constant and neutral hyperconjugation, but the β bond shows a strong relationship.Key words: hyperconjugation, germanium, σ-π conjugation, silicon, tin.

Lignans of western red cedar (Thujaplicata Donn). X. γ-Thujaplicatene

1970 ◽  
Vol 48 (20) ◽  
pp. 3144-3146 ◽  
Author(s):  
Bruce F. MacDonald ◽  
G. M. Barton
Keyword(s):  
Double Bond ◽  
Aromatic Ring ◽  
Red Cedar ◽  
Synthetic Derivative ◽  
Western Red Cedar

The structure of the tenth in the series of novel lignans from the heartwood of western red cedar (Thujaplicata Donn) has been determined as 2-(3″,4″-dihydroxy-5″-methoxybenzylidene)-3-(4′-hydroxy-3′-methoxybenzyl)-butyrolactone (γ-thujaplicatene) (1) by spectrometric methods and comparison with synthetic derivative reactions. The discovery of this lignan with a double bond conjugated with an aromatic ring confirms previously suggested biosynthetic routes to the cedar lignans.

scholarly journals Piperlongumine Analogs Promote A549 Cell Apoptosis through Enhancing ROS Generation

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3243
Author(s):  
Ai-Ling Sun ◽  
Wen-Wen Mu ◽  
Yan-Mo Li ◽  
Ya-Lei Sun ◽  
Peng-Xiao Li ◽  
...  
Keyword(s):  
Double Bond ◽  
Aromatic Ring ◽  
A549 Cell ◽  
Redox Balance ◽  
Chemotherapeutic Agents ◽  
Ros Generation ◽  
Cycle Arrest ◽  
Ros Accumulation ◽  
Electric Effect

Chemotherapeutic agents, which contain the Michael acceptor, are potent anticancer molecules by promoting intracellular reactive oxygen species (ROS) generation. In this study, we synthesized a panel of PL (piperlongumine) analogs with chlorine attaching at C2 and an electron-withdrawing/electron-donating group attaching to the aromatic ring. The results displayed that the strong electrophilicity group at the C2–C3 double bond of PL analogs plays an important role in the cytotoxicity whereas the electric effect of substituents, which attached to the aromatic ring, partly contributed to the anticancer activity. Moreover, the protein containing sulfydryl or seleno, such as TrxR, could be irreversibly inhibited by the C2–C3 double bond of PL analogs, and boost intracellular ROS generation. Then, the ROS accumulation could disrupt the redox balance, induce lipid peroxidation, lead to the loss of MMP (Mitochondrial Membrane Potential), and ultimately result in cell cycle arrest and A549 cell line death. In conclusion, PL analogs could induce in vitro cancer apoptosis through the inhibition of TrxR and ROS accumulation.

1-(7-Chloro-1,4-dihydroquinolin-4-ylidene)thiosemicarbazide and its hydrochloride: evidence for the existence of a stable imine tautomer in the solid state of 4-aminoquinoline free bases, an anomalous case in nitrogen heterocycles

2015 ◽  
Vol 71 (7) ◽  
pp. 564-569 ◽  
Author(s):  
Rafael C. Machado ◽  
Richard M. Grazul ◽  
Renata Diniz
Keyword(s):  
Double Bond ◽  
Solid State ◽  
Crystal Structures ◽  
Aromatic Ring ◽  
Tautomeric Form ◽  
Bond Angle ◽  
Nitrogen Heterocycles ◽  
Hydrochloride Salt ◽  
Substituted Quinolines ◽  
Bond Character

In the solid state, crystals of both 1-(7-chloro-1,4-dihydroquinolin-4-ylidene)thiosemicarbazide–methanol–water (2/1/1), 2C10H9ClN4S·CH3OH·H2O, (I), and its hydrochloride salt {systematic name: [(7-chloro-1,4-dihydroquinolin-4-ylidene)azaniumyl]thiourea chloride}, C10H10ClN4S+·Cl−, (II), assume the imine tautomeric form, contrary to other 4-amino-7-chloroquinolines. Of particular interest are the N—C bond lengths, which have appreciable double-bond character, and the C—N—C aromatic ring bond angle. Both of these parameters have been studied extensively in 4-amino-substituted quinolines. The crystal structures of (I) and (II) in this study provide interesting examples of the amino–imino tautomerism which exists in this class of compound and is, to the best of our knowledge, hitherto unreported.

Sign in / Sign up

Export Citation Format

Share Document