628-80-8Relevant academic research and scientific papers
CHEMOSELECTIVE MONOALKYLATION OF 5-TRIFLUOROACETAMIDO- AND 5-ACETAMIDO-1-PENTANOL DERIVATIVES VIA N,O-BISDEPROTONATION. QUANTITATION OF EVOLVED H2 AS A PROBE OF ANION FORMATION.
Hirschmann, Ralph,Hynes, John, Jr.,Grant Spoors, P.,Smith, Amos B.
, p. 2373 - 2376 (1995)
Measurements of H2 evolution revealed that neither 5-trifluoroacetamido-1-pentanol (1) nor 5-acetamido-1-pentanol (6) underwent complete bisdeprotonation upon treatment with excess NaH in THF, thereby accounting for the unexpected course of subsequent alkylations with carbohydrate-derived triflates 2 and 7.These studies in turn led to an effective protocol for generation of N,O-dianions from 1 and 6; as anticipated, the former chemoselectively furnished O-alkylation products with triflates 2 and 15.
Practical and Selective sp3 C?H Bond Chlorination via Aminium Radicals
McMillan, Alastair J.,Sieńkowska, Martyna,Di Lorenzo, Piero,Gransbury, Gemma K.,Chilton, Nicholas F.,Salamone, Michela,Ruffoni, Alessandro,Bietti, Massimo,Leonori, Daniele
supporting information, p. 7132 - 7139 (2021/03/03)
The introduction of chlorine atoms into organic molecules is fundamental to the manufacture of industrial chemicals, the elaboration of advanced synthetic intermediates and also the fine-tuning of physicochemical and biological properties of drugs, agrochemicals and polymers. We report here a general and practical photochemical strategy enabling the site-selective chlorination of sp3 C?H bonds. This process exploits the ability of protonated N-chloroamines to serve as aminium radical precursors and also radical chlorinating agents. Upon photochemical initiation, an efficient radical-chain propagation is established allowing the functionalization of a broad range of substrates due to the large number of compatible functionalities. The ability to synergistically maximize both polar and steric effects in the H-atom transfer transition state through appropriate selection of the aminium radical has provided the highest known selectivity in radical sp3 C?H chlorination.
Peter J Derrick and the Grand Scale ‘Magnificent Mass Machine’ mass spectrometer at Warwick
Colburn,Derrick, Peter J,Bowen, Richard D
, p. 319 - 326 (2018/01/27)
The value of the Grand Scale ‘Magnificent Mass Machine’ mass spectrometer in investigating the reactivity of ions in the gas phase is illustrated by a brief analysis of previously unpublished work on metastable ionised n-pentyl methyl ether, which loses predominantly methanol and an ethyl radical, with very minor contributions for elimination of ethane and water. Expulsion of an ethyl radical is interpreted in terms of isomerisation to ionised 3-pentyl methyl ether, via distonic ions and, possibly, an ion-neutral complex comprising ionised ethylcyclopropane and methanol. This explanation is consistent with the closely similar behaviour of the labelled analogues, C3H7CH2CD2OCH3 +. and C3H7CD2CH2OCH3 +., and is supported by the greater kinetic energy release associated with loss of ethane from ionised n-propyl methyl ether compared to that starting from directly generated ionised 3-pentyl methyl ether.
Synthesis of alkyl methyl ethers and alkyl methyl carbonates by reaction of alcohols with dimethyl carbonate in the presence of tungsten and cobalt complexes
Khusnutdinov,Shchadneva,Mayakova
, p. 790 - 795 (2014/08/18)
Alkyl methyl ethers and alkyl methyl carbonates were synthesized by reaction of alcohols with dimethyl carbonate in the presence of tungsten and cobalt carbonyls. Optimal reactant and catalyst ratios, as well as reaction conditions, were found for selective formation of alkyl methyl ethers or alkyl methyl carbonates.
Self-optimizing continuous reactions in supercritical carbon dioxide
Parrott, Andrew J.,Bourne, Richard A.,Akien, Geoffrey R.,Irvine, Derek J.,Poliakoff, Martyn
experimental part, p. 3788 - 3792 (2011/06/22)
Hands-free optimization: A combination of an automated flow reactor, online analysis, and a control algorithm leads to efficient optimization of reactions to a given product without the need for human intervention.
Raman spectroscopy of n-pentyl methyl ether and deuterium labelledanalogues
Bowen, Richard D.,Edwards, Howell G. M.,Farwell, Dennis W.,Morgan, Sara E
experimental part, p. 1725 - 1734 (2012/04/04)
The Raman spectra of n-pentyl methyl ether, C5H 11OCH3, and six selectively deuteriated analogues arereported and discussed. Correlations between the observed ν(sp 3CH)stretching and bending bands and the position of the deuterium atoms in thealkyl chain are developed and refined. Similar progress is possible inassociating specific skeletal vibrations with bands in the Raman spectra. Therelevance of this study to improving the assignment of bands in the Ramanspectra of larger systems of biological interest is highlighted. Copyright
The continuous acid-catalysed etherification of aliphatic alcohols using stoichiometric quantities of dialkyl carbonates
Parrott, Andrew J.,Bourne, Richard A.,Gooden, Peter N.,Poliakoff, Martyn,Irvine, Derek J.,Bevinakatti, Han. S.
experimental part, p. 1420 - 1426 (2011/09/20)
A range of methyl and ethyl ethers of aliphatic alcohols have been synthesized cleanly in high yield by reacting the corresponding alcohol with dimethyl carbonate or diethyl carbonate over the solid acid catalyst, I-alumina. The reaction could be conducted at ambient pressure without the need for the large excess of dialkyl carbonate as previously reported in the literature. If the reaction was conducted at high pressure, the conversion of the starting alcohol was greatly reduced. However, high pressure CO2 can be used as the solvent without significant reduction in yield. This has implications for tandem reactions.
Direct methylation of primary and secondary alcohols by trimethyl phosphate to prepare pure alkyl methyl ethers
Van Dyke Tiers, George
, p. 1223 - 1233 (2007/10/03)
Primary and secondary alcohols and diols react autocatalytically with trimelhyl phosphate plus small amounts of polyphosphoric acid at 185°C to give the corresponding methyl ethers. High purity and good yields are achieved when the ether is distilled from the reaction mixture as it is formed. By controlled addition even low-boiling alcohols can be methylated successfully. The reaction mechanism is undetermined. Peroxide formation in ethers is inhibited by storage over 10 molal KOH. Pure isotropic optical crystals are used for refractometer calibration. Improved physical property and NMR data (1H and 13C) are reported for thirteen methyl ethers. Simple two-point linear extrapolation of NMR shifts (especially 13C) to infinite dilution produces highly reproducible δ°-values (to 0.01 ppm or better) which uniquely characterize a molecule even when unidentified and/or not isolated from a mixture. This capability appears not to have been recognized in the literature. Acta Chemica Scandinavica 1998.
SYNTHETIC APPLICATION OF MICELLAR CATALYSIS. WILLIAMSON'S SYNTHESIS OF ETHERS
Jursic, Branko
, p. 6677 - 6680 (2007/10/02)
A simple, rapid and efficient procedure for the preparation of di-alkyl, simple phenyl-alkyl and hindered phenyl-alkyl ethers has been developed.Based on the principle of micellar catalysis the method involves alkylation of the alkoxide or the phenoxide ion with an alkyl chloride at 80 deg C in the presence of cationic micelles.For the preparation of phenyl-alkyl ethers normal micelles were used, while for the di-alkyl ethers reverse micelles were more effective.By increasing the ionic strength of the solution the rate of formation of phenyl-alkyl ethers could be increased.
