- Correlation of Alkyl and Polar Substituents at the Alcoholic Side of Tertiary Acetates with the Rate of Pyrolyses in the Gas Phase
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The rate coefficients for the gas-phase pyrolysis of several tertiary acetates have been measured in a static system over the temperature range of 220-340 deg C and pressure range of 40-186 torr.In seasoned vessels the reactions are homogeneous, follow a first-order rate law, and are unimolecular.The temperature dependence of the rate coefficients is given by the following Arrhenius equations: for 3,3,3-trichloro-2-methyl-2-propyl acetate, log k1 (s-1) = (13.86 +/- 0.35) - (188.8 +/- 3.8) kJ mol-1 (2.303 RT)-1; for methyl α-acetoxyisobutyrate, log k1 (s-1) = (12.42 +/- 0.28) - (174.6 +/- 3.2) kJ mol-1 (2.303 RT)-1; for 2-methyl-2-hexyl acetate, log k1 (s-1) = (13.35 +/- 0.33) - (166.1 +/- 3.4) kJ mol-1 (2.303 RT)-1; for 2,4-dimethyl-2-pentyl acetate, log k1 (s-1) = (12.42 +/- 0.19) - (154.1 +/- 1.9) kJ mol-1 (2.303 RT)-1; for 2-methyl-2-acetoxy-4-phenylbutane, log k1 (s-1) = (11.97 +/- 0.55) - (151.5 +/-5.6) kJ mol-1 (2.303 RT)-1.The effectof substituents in the gas-phase elimination of 2-substituted 2-propyl acetates may be either electronic or steric in nature.The linear correlations for electron-releasing groups and for electron-withdrawing groups are presented and discussed.The results of the present work together with those reported in the literature lead to the establishment of a possible generalization on the influence of substituents at the alcohols side of primary, secondary, and tertiary acetates pyrolyses in the gas phase.
- Gonzalez, Neil,Martin, Ignacio,Chuchani, Gabriel
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- Synthesis and evaluation of 1,1,7,7-tetramethyl-9-azajulolidine (TMAJ) as a highly active derivative of N,N-dimethylaminopyridine
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1,1,7,7-Tetramethyl-9-azajulolidine (TMAJ), which theoretical studies have suggested as a highly active DMAP analog, was synthesized for the first time. The catalytic activity of TMAJ was confirmed by the acetylation reactions of various tert-alcohols. TMAJ showed much higher catalytic activity than DMAP and one of the highest activity levels among the conventional DMAP analogs. These experimental results were in good agreement with the previous theoretical studies.
- Tsutsumi, Tomohiro,Saitoh, Arisa,Kasai, Tomoyo,Chu, MengYue,Karanjit, Sangita,Nakayama, Atsushi,Namba, Kosuke
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supporting information
(2020/05/28)
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- PREPARATION OF ACETATE COMPOUNDS VIA A KETENE COMPOUND
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The present invention relates to a method for preparing acetate compounds using ketene.
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Page/Page column 19
(2019/07/13)
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- Hypervalent iodine(III)-mediated decarboxylative acetoxylation at tertiary and benzylic carbon centers
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The decarboxylative acetoxylation of carboxylic acids using a combination of PhI(OAc)2 and I2 in a CH2Cl2/AcOH mixed solvent is reported. The reaction was successfully applied to two types of carboxylic acids containing an α-quaternary and a benzylic carbon center under mild reaction conditions. The resulting acetates were readily converted into the corresponding alcohols by hydrolysis.
- Kiyokawa, Kensuke,Okumatsu, Daichi,Minakata, Satoshi
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supporting information
p. 1046 - 1050
(2019/11/11)
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- Dehydroxylation of alcohols for nucleophilic substitution
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The Ph3P/ICH2CH2I system-promoted dehydroxylative substitution of alcohols was achieved to construct C-O, C-N, C-S and C-X (X = Cl, Br, and I) bonds. Compared with the previous approaches such as the Appel reaction and Mitsunobu reaction, this protocol offers some practical advantages such as safe operation and a convenient amination process.
- Chen, Jia,Lin, Jin-Hong,Xiao, Ji-Chang
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p. 7034 - 7037
(2018/07/05)
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- Synthesis of a wide range of thioethers by indium triiodide catalyzed direct coupling between alkyl acetates and thiosilanes
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An indium triiodide-catalyzed substitution of the acetoxy group in alkyl acetates with thiosilanes provides access to a variety of thioethers. The method is efficient for a wide scope of acetates such as primary alkyl, secondary alkyl, tertiary alkyl, allylic, benzylic, and propargylic acetates.
- Nishimoto, Yoshihiro,Okita, Aya,Yasuda, Makoto,Baba, Akio
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supporting information; experimental part
p. 1846 - 1849
(2012/06/18)
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- Reactions with Umpolung via Radicals: CC-Bond Formation between Ketones and Alkenes
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The hydrazones 1 - 11 from ketones react in a general synthetic procedure with alkenes 33a - m to yield products 34 - 44 (table 2 and 3).Important intermediates of these reactions with umpolung are 1-acetoxyalkyl radicals 49 that are formed from organomercuric salts 14 - 24 by reduction with NaBH4.This new CC-bond formation reaction can be carried out in a one-pot synthesis without isolation of the metalorganic compounds (table 4). - In side reactions the reduction products 50 are formed, if bulky starting compounds or less reactive alkenes are used (table 5 and 6).
- Giese, Bernd,Erfort, Ulrich
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p. 1240 - 1251
(2007/10/02)
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