A matrix isolation study of the photochemically induced reactions of nitrogen dioxide with 1,2-dibromoethene and 1,2-dichloroethene using Fourier transform infrared spectroscopy
Photolyses of matrices of either BrCHCHBr/NO2/Ar or ClCHCHCl/NO2/Ar using quartz-filtered radiation (λ > 240 nm) led to the appearance of infrared bands attributable to carbonyl, carbon monoxide, and ketene species; no bands belonging to a precursor complex NO 2...XCHCHX (where X = Br or Cl) were observed upon matrix deposition. The possible reaction pathway is discussed.
Phosphoric anhydride in the synthesis of monosubstituted ketenes and related dimers
Monosubstituted ketenes and related condensation products, including phosphorylated, were obtained by the action of phosphoric anhydride on ethyl esters of monosubstituted acetic and malonic acids.
Zavlin, P. M.,Efremov, D. A.,Essentseva, N. S.,Tebby, J. C.
p. 529 - 532
(2007/10/03)
The Phosphorylation of Organic Compounds by Phosphoric Anhydride. Part 3. Synthesis of Monosubstituted Ketenes in the Reaction of Esters with Phosphoric Anhydride and cyclotrimerization of these Ketenes
Monosubstituted ketenes 1 have been synthesized from substituted acetic esters 2 by elimination of alcohol under the action of phosphoric anhydride.The ketenes undergo cyclotrimerization to give substituted phloroglucinols (1,3,5-trihydroxybenzenes) 3 and their phosphorylated derivatives.
Efremov, Dimitry A.,Zavlin, Pavel M.,Essentseva, Nataly S.,Tebby, John C.
p. 3163 - 3168
(2007/10/02)
Preparation, Structure, and Thermal Behaviour of (2-Chloroacyl)diphenylphosphanes - a New Pathway to Chloroketenes
The chlorinated acylphosphanes RC(O)-PPh2 (2a - f) are obtained by the reaction of the acyl chlorides RC(O)Cl (1a - f) with (CH3)3SiPPh2 in ether at -80 deg C.HCCl2C(O)-PPh2 (2c) crystallizes monoclinicly in the space group P21/c with Z = 8.As a result of steric caused electronic effects with increasing degree of chlorination in the series 2b -> 2c -> 2d a stepwise high field shift of the signals in the 31P-NMR spectra is observed. 2b - d, f are thermally labile and decompose with formation of ClPPh2 (3) and ketene at 80 deg C.The chloroketenes HCClCO (4) and CH3CClCO (5) are detected for the first time directly by means of their 13C NMR spectra.Between 0 and 40 deg C 2d also yields Cl3PPh2 (6).With cyclohexene or aniline 4 reacts to give the trapping products 8 and 9, respectively.