18370-86-0Relevant academic research and scientific papers
A method of manufacturing an aromatic vinyl ether
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Paragraph 0075-0077, (2016/12/16)
[Problem] To provide a method for producing an aromatic vinyl ether, which can overcome disadvantages of the conventional techniques and can produce aromatic vinyl ethers having various structures safely using a simple apparatus without using any expensive catalyst. [Solution] This method for producing an aromatic vinyl ether is characterized by comprising heating an aromatic vinyl ether (1) that has such a structure that a hydrogen atom in a phenolic hydroxy group is substituted by a vinyloxyethyl group and is represented by formula (1) (wherein R represents a residue of a phenol having n phenolic hydroxy groups; and n represents an integer of 1 to 3) without any solvent or in an aprotic polar solvent in the presence of an alkali metal compound to thereby convert the aromatic vinyl ether (1) into an aromatic vinyl ether (2) that has such a structure that a hydrogen atom in a phenolic hydroxy group is substituted by a vinyl group and is represented by formula (2) (wherein R and n are as defined above).
Intramolecular triplet energy transfer in flexible molecules: Electronic, dynamic, and structural aspects
Wagner, Peter J.,Klan, Petr
, p. 9626 - 9635 (2007/10/03)
Exothermic intramolecular triplet energy transfer (TET) rate constants in various flexible bichromophoric systems D-(CH2)n-O-A (D = benzoyl, 4-methylbenzoyl; A = 2-naphthyl, 4-, 3-, 2-biphenyl; n = 3-14) have been determined from steady-state quenching and quantum yield measurements. The magnitude of the rate constants in molecules where n = 3 is comparable to those in molecules with a rigid spacer between chromophores, so that a through-bond mechanism is presumed to remain important. A very gradual drop in TET rate constants as the connecting polymethylene chain becomes longer indicates that through-space interactions compete and apparently provide the only mechanism responsible for transfer when n ≥ 5. Rate constants in long molecules (n = 11-14) remain remarkably high (～108 s-1) - lower than in those with four-atom tethers by only 1 order of magnitude. This effect is explained on the basis of rapid conformational equilibria always keeping a sufficient fraction of the molecules coiled so that the two chromophores are close enough to interact within 10 ns, the time required for the competing γ-hydrogen abstraction used to monitor triplet lifetimes. Energy transfer accounts for 40-75% of triplet decay for the longer molecules. This high efficiency indicates that only a small fraction involves static quenching in ground-state conformers with the two ends within 4 A. The majority must represent a combination of rate-determining bond rotations to such geometries and equilibrated conformations with their ends farther apart but still able to undergo energy transfer within 10 ns. Thus, the measured rate constants are, in fact, a weighted average of three different conformational mechanisms. The decrease in rate constant with tether length is not monotonic: a relative increase in rate for medium-chain-length molecules is explained by a larger number of favorable conformers and further, in biphenyl derivatives, by a rotation along the terminal O-C bond between the tether and the aromatic ring. As was expected, replacement of the polymethylene tether with poly(ethylene oxide) promotes better flexibility and thus higher transfer rates. Rate constants were found to be lower by a factor of ～2 when biphenyl rather than naphthyl is the acceptor, in agreement with earlier bimolecular measurements. With the 4-methylbenzoyl group (π,π* lowest triplet) as donor instead of benzoyl (n,π* lowest triplet), a small (～1.5x) but consistent rate increase occurred for all tether lengths.
Synthesis of Bis(aryloxyethyl) Vinyl Ethers via Phase-Transfer-Catalyzed Nucleophilic Displacement on 2-Chloroethyl Vinyl Ether
Gallucci, R.R.,Going, R.C.
, p. 342 - 346 (2007/10/02)
Bis(aryloxyethyl) vinyl ethers can be prepared in high yield by using sodium hydroxide, bis(phenols), and 2-chloroethyl vinyl ether (CEVE) with a tetraalkylammonium salt phase-transfer catalyst.The displacement reaction of the bis(phenol) dianion proceeds in high yield only if both excess CEVE and base are employed.Nucleophilic displacement is considerably faster than elimination reactions involving solvent or catalyst.Small amounts of water have little effect on the reaction.The synthesis has been extended to the preparation of related monoaryloxyethyl vinyl ethers.
