Captodative olefins are highly reactive and selective substrates in Diels-Alder and 1,3-dipolar cycloadditions. Seeking an explanation of this fact based on molecular energetics, the thermochemical analysis of 1-acetyl vinyl p-nitrobenzoate, a captodative olefin, has been performed using semi-micro-combustion calorimetry, effusion measurements through a quartz crystal microbalance, and differential scanning calorimetry. The molar standard combustion energy and enthalpy as well as the molar standard formation enthalpy are reported along with sublimation and melting enthalpies. From these data, experimental formation enthalpy of the gas-phase is derived and compared with the theoretical value calculated through the density functional theory procedure. The olefinic bond enthalpy is also computed from experimental data, and the relevance of the results is discussed.
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http://dx.doi.org/10.1021/acs.jpca.5b01526 | DOI Listing |
J Nat Prod
February 2020
Environmental Futures Research Institute , Griffith University, Gold Coast , QLD 4222 , Australia.
Antiplasmodial high-throughput screening of extracts derived from marine invertebrates collected from northern NSW, Australia, resulted in the methanol extract of the bryozoan being identified as inhibitory toward the 3D7 strain of . Purification of this extract resulted in two new bis-β-carbolines that possess a cyclobutane moiety, orthoscuticellines A and B ( and ), three new β-carboline alkaloids, orthoscuticellines C-E (-), and six known compounds, 1-ethyl-4-methylsulfone-β-carboline (), 1-ethyl-β-carboline (), 1-acetyl-β-carboline () 1-(1'-hydroxyethyl)-β-carboline (), 1-methoxycarbonyl-β-carboline (), and 1-vinyl-β-carboline (). The structures of all compounds were determined from analysis of MS and 1D and 2D NMR data.
View Article and Find Full Text PDFToxicol Appl Pharmacol
October 2019
Department of Toxicology, School of Public Health, Shanxi Medical University, Taiyuan, China. Electronic address:
Vinyl chloride (VC) is a common industrial organochlorine, shown to cause hepatic angiosarcoma and hepatic steatosis. However, the role of endoplasmic reticulum stress (ERS) and oxidative stress (OS) in hepatic steatosis after subchronic exposure to VC in mice, is unclear. Based on body weight, forty healthy SPF male C57BL/6 J mice were randomly divided into a control group and three VC exposure groups (57.
View Article and Find Full Text PDFJ Phys Chem A
May 2015
‡Departamento de Química Orgánica, Escuela Nacional de Ciencias Biológicas del IPN, Prolongación Carpio y Plan de Ayala S/N, México D.F. C.P.11340, Mexico.
Captodative olefins are highly reactive and selective substrates in Diels-Alder and 1,3-dipolar cycloadditions. Seeking an explanation of this fact based on molecular energetics, the thermochemical analysis of 1-acetyl vinyl p-nitrobenzoate, a captodative olefin, has been performed using semi-micro-combustion calorimetry, effusion measurements through a quartz crystal microbalance, and differential scanning calorimetry. The molar standard combustion energy and enthalpy as well as the molar standard formation enthalpy are reported along with sublimation and melting enthalpies.
View Article and Find Full Text PDFJ Am Chem Soc
September 2003
Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA.
The cycloisomerization of diyne-ols catalyzed by [CpRu(CH3CN)3]PF6 to 2-vinyl-1-acylcycloalkenes proceeds via a ruthenacyclopentadiene involving initial ionization of the tertiary or secondary alcohol, followed by readdition. In the case of primary alcohols, a competing pathway wherein water first adds would appear to occur. The feasibility of this proposed minor pathway was tested in the reaction of diynes in the presence of water.
View Article and Find Full Text PDFInorg Chem
May 2003
Department of Chemistry, National University of Singapore, Kent Ridge, Singapore 119260.
A new chiral auxiliary, (+/-)-N,N-dimethyl-1-(2,5-dimethylphenyl)ethylamine, was designed and synthesized in two steps from 1-acetyl-2,5-dimethylbenzene. Its cyclopalladated dimeric complex could be efficiently resolved via the formation of (S)-prolinate derivatives. Both hand forms of the complex could be obtained in similar yields.
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