- Pd(II)-catalyzed acetalization of terminal olefins with electron-withdrawing groups in supercritical carbon dioxide: selective control and mechanism
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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.
- Wang, Zhao-Yang,Jiang, Huan-Feng,Ouyang, Xiao-Yue,Qi, Chao-Rong,Yang, Shao-Rong
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p. 9846 - 9854
(2007/10/03)
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- PRECURSORS OF 3-ALKOXYALKANOLS AND PROCESSES FOR THE PREPARATION OF 3-ALKOXYALKANOLS
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Processes for the preparation of 3-alkoxyalkanols useful as solvents for coating materials, photoresists, or the like.Specifcally,(1) a process which comprises reacting an α,β-unsaturated aldehyde with an alcohol in the presence of an acidic catalyst and subjecting the obtained product to hydrolysis and hydrogenation successively;(2) a process which comprises subjecting a reaction mixture obtained by the reaction of an α,β-unsaturated aldehyde with an alcohol and comprising the corresponding 1,1,3-trialkoxyalkane and 3-alkoxyalkanal to hydrolysis and hydrogenation at the same time;(3) a process which comprises recovering a 3-alkoxyalkanal through distillation as an azeotropic mixture thereof with water from a reaction solution obtained by the reaction of an alcohol with acid-containing acrolein or methacrolein prepared by the oxidation of propylene or isobutylene, and hydrogenating the recovered 3-alkoxyalkanal into the corresponding 3-alkoxyalkanol; and(4) a process which comprises bringing a gas produced by the oxidation of propylene or isobutylene Into contact with an alcohol, conducting the reaction of the gas with the alcohol to form the corresponding 1,1,3-trialkoxyalkane, and subjecting it to hydrolysis and hydrogenation.
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- Palladium(II)-catalyzed acetalization of allylic acetates and its utilization for the synthesis of 2-cyanovinyl ketones
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α-Cyanoallyl acetate (1 a), when treated with methanol in the presence of bis(acetonitrile)dichloropalladium(II) catalyst, is acetalized at the terminal olefinic carbon to give 1-cyano-3,3-dimethoxypropyl acetate (2). γ-Substituted α-cyanoallyl acetates give 3-substituted 1-cyano-3-oxo-propyl acetates 5 from which 2-cyanovinyl ketones 11 are obtained in good yields.
- Hosokawa,Aoki,Murahashi
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p. 558 - 561
(2007/10/02)
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