6975-85-5Relevant articles and documents
Pd(II)-catalyzed acetalization of terminal olefins with electron-withdrawing groups in supercritical carbon dioxide: selective control and mechanism
Wang, Zhao-Yang,Jiang, Huan-Feng,Ouyang, Xiao-Yue,Qi, Chao-Rong,Yang, Shao-Rong
, p. 9846 - 9854 (2007/10/03)
Pd(II)-catalyzed acetalization of terminal olefins with electron-withdrawing groups was carried out smoothly in supercritical carbon dioxide under oxygen atmosphere when polystyrene-supported benzoquinone (PS-BQ) or CuII (CuI) chloride was employed as cocatalyst. The higher selectivity was achieved, without any chlorinated by-product detected, when using PS-BQ instead of CuII (or CuI) chloride. PS-BQ could be recycled with excellent catalytic activity remaining after each simple filtration. Chlorine ion was demonstrated to be a promoter. The different acetalization mechanisms were revealed by the subtle relationship of chlorine ion and benzoquinone (BQ) to the catalytic activity of PdCl2/PS-BQ, PdII-CuCl2 or Pd(OAc)2/PS-BQ.
Products of the gas-phase reactions of the OH radical with n-butyl methyl ether and 2-isopropoxyethanol: Reactions of ROC(O)
Aschmann, Sara M.,Atkinson, Roger
, p. 501 - 513 (2007/10/03)
The products of the gas-phase reactions of the OH radical with n-butyl methyl ether and 2-isopropoxyethanol in the presence of NO have been investigated at 298±2 K and 740 Torr total pressure of air by gas chromatography and in situ atmospheric pressure ionization tandem mass spectrometry. The products observed from n-butyl methyl ether were methyl formate, propanal, butanal, methyl butyrate, and CH3C(O)CH2CH2OCH3 and/or CH3CH2C(O)CH2OCH3, with molar formation yields of 0.51±0.11, 0.43±0.06, 0.045±0.010, approximately 0.016, and 0.19±0.04, respectively. Additional products of molecular weight 118, 149 and 165 were observed by API-MS/MS analyses, with those of molecular weight 149 and 165 being identified as organic nitrates. The products observed and quantified from 2-isopropoxyethanol were isopropyl formate and 2-hydroxyethyl acetate, with molar formation yields of 0.57±0.05 and 0.44±0.05, respectively. For both compounds, the majority of the reaction products and reaction pathways are accounted for, and detailed reaction mechanisms are presented. The results of this product study are combined with previous literature product data to investigate the tropospheric reactions of R1R2C(O)OR radicals formed from ethers and glycol ethers, leading to a revised estimation method for the calculation of reaction rates of alkoxy radicals.
Aschmann, Sara M.,Atkinson, Roger
, p. 501 - 513 (2007/10/03)
The products of the gas-phase reactions of the OH radical with n-butyl methyl ether and 2-isopropoxyethanol in the presence of NO have been investigated at 298±2 K and 740 Torr total pressure of air by gas chromatography and in situ atmospheric pressure ionization tandem mass spectrometry. The products observed from n-butyl methyl ether were methyl formate, propanal, butanal, methyl butyrate, and CH3C(O)CH2CH2OCH3 and/or CH3CH2C(O)CH2OCH3, with molar formation yields of 0.51±0.11, 0.43±0.06, 0.045±0.010, approximately 0.016, and 0.19±0.04, respectively. Additional products of molecular weight 118, 149 and 165 were observed by API-MS/MS analyses, with those of molecular weight 149 and 165 being identified as organic nitrates. The products observed and quantified from 2-isopropoxyethanol were isopropyl formate and 2-hydroxyethyl acetate, with molar formation yields of 0.57±0.05 and 0.44±0.05, respectively. For both compounds, the majority of the reaction products and reaction pathways are accounted for, and detailed reaction mechanisms are presented. The results of this product study are combined with previous literature product data to investigate the tropospheric reactions of R1R2C(O)OR radicals formed from ethers and glycol ethers, leading to a revised estimation method for the calculation of reaction rates of alkoxy radicals.
Phase-Transfer Catalyzed Reactions. 5. Dramatic Effect of the Concentration of Base on the Dimerization of Crotonaldehyde
McIntosh, John M.,Khalil, Hamdy,Pillon, David W.
, p. 3436 - 3439 (2007/10/02)
Self-condensation of crotonaldehyde under base-catalyzed phase-transfer conditions leads to aldehydes 3 or 4, depending only on the concentration of aqueous hydroxide used.Quaternary ammonium fluorides in anhydrous THF is shown to be a useful system for conjugate additions involving base-sensitive aldehydes.
