- Thermolysis of alkoxyaluminum and siloxyaluminum acylates
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Thermolysis of alkoxyaluminum acylates (RO)nAl(OCORt)3-n (n = 1, 2; R = i-Pr, s-Bu, t-Bu, Rt = Ph, CH2I; R = PhCH2, Rt = Me, Et, Ph; R = Me3Si, Et3Si, Rt = Me) was studied. The main direction of thermolysis of derivatives of primary and secondary alcohols and of unsubstituted carboxylic acids is ester and alcohol formation. Trialkylsiloxyaluminum acylates termolyze to give in the first stage no other products than trialkylacyloxysilanes. Thermolysis of iodoacylates (RO)2AlOCOCH2I (R = Pr, s-Bu) involves oxidation of the alkoxy group to carbonyl compounds with simultaneous formation of a ketene and hydrogen iodide. tert-Butoxyaluminum acylates regardless of the structure of substituent in the acyloxy group undergo symmetrization to aluminum tert-butylate.
- Stepovik,Kazakina,Martynova
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p. 1371 - 1377
(2007/10/03)
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- Isoprene process
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The present invention is directed to a process for producing dienes which involves reacting a reaction mixture of tertiary alkyl ether and a source of oxygen over two functionally distinct catalysts under reaction conditions sufficient to produce high yields of the dienes with minimal recycle of the ether. The two functionally different catalysts are selected from a group of bifunctional catalysts having both oxidation sites and acidic sites and monofunctional acidic catalysts, such as bifunctional catalysts containing components selected from a group of oxides of vanadium, tungsten, molybdenum, copper, iron, chromium, and uranium and mixtures thereof; and monofuctional acid catalysts such as acid treated montmorillonite clays, and acid catalysts comprising an inorganic amorphous or substantially amorphous oxide material comprising the following components reacted therein: wherein M1 is at least one Group IIIB element selected from the group consisting of Al, Ga, In and Tl; M2 is at least one Group IVb element selected from the group of Si, Sn and Ge. The bifunctional catalysts are used in a first stage reaction, and the monofunctional acidic catalysts are used in a second stage reaction.
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