- Thermolysis of 2,2-dimethoxy-5,5-dimethyl-Δ3-1,3,4-oxadiagoline studied with photoelectron spectroscopy. He(I) photoelectron spectrum of dimethoxycarbene
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Gas phase thermolysis of 2,2-dimethoxy-5,5-dimethyl-Δ3-1,3,4-oxadiazoline (1) in an ultraviolet photoelectron spectrometer by means of a CW CO2 laser as directed heat source at 26 W gave a complex PE spectrum that included ionization bands belonging to acetone, tetramethoxyethylene (3), and dimethyl oxalate (4). Subtraction of the spectra of acetone, 3, and 4 from the pyrolysis spectrum of 1 left a simple PE spectrum that is attributed to dimethoxycarbene (2) along with some ethane. Becke3LYP/6-31+G* calculations gave first adiabatic and vertical ionization potentials of 2 as well as orbital energies that are in perfect agreement with experimental values. From the available experimental and calculational data, 2 is assumed to adopt a w conformation.
- Muchall,Werstiuk,Choudhury,Ma,Warkentin,Pezacki
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p. 238 - 240
(2007/10/03)
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- Nucleophilic aromatic substitution with dialkoxycarbenes
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Dimethoxycarbene, generated at 110°C by thermolysis of 2,2-dimethoxy-5,5-dimethyl-Δ3-1,3,4-oxadiazoline, displaces fluoride from aromatic rings that are activated with electron-withdrawing groups. Intermolecular substitution on Sanger's reagent and on hexafluorobenzene are reported, together with intramolecular substitution by a dioxycarbene with a tethered aryl group.
- Ross, Joseph P.,Couture, Philippe,Warkentin, John
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p. 1331 - 1335
(2007/10/03)
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