- Photocatalytic Conversion of a FeCl3–CCl4–ROH System
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The photocatalytic transformations of carbon tetrachloride and aliphatic primary alcohols in the presence of iron trichloride and a molar ratio of components FeCl3: CCl4: ROH = 1: 300: 2550 were studied. CCl4 is transformed into chloroform and hexachloroethane after exposure to a mercury lamp (250 W) to the FeCl3–CCl4–ROH system at 20°C, whereas the primary ROH alcohols are selectively oxidized into acetals (1,1-dialkoxyalkanes). The maximum conversion of CCl4 reaches 80%. The kinetics and mechanism of the photocatalytic conversion of the FeCl3–CCl4–ROH system are considered.
- Makhmutov
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p. 695 - 700
(2018/03/08)
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- CATALYST CAPABLE OF FORMING 2,5-DIMETHYLHEXENES
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A process of making a catalyst and the catalyst composition made by that process comprising a multinuclear metal compound of the formula Ma(PCy3)b(H)c(CO)d(OR)e(H2O)f with molar ratios a:b:c:d:e:f, wherein a is in the range from 2 to 2000, b is in the range from 0 to 4000, c is in the range from 0 to 6000 and d is in the range from 0 to 2000, e is in the range from 1 to 2000, and f is in the range from 0 to 100; wherein PCy3 indicates tricyclohexylphosphine, H indicates hydride, R is an alkyl group determined by the alcohol utilized and H2O is water from the reaction; and a is at least twice w. A method of making one or more 2,5-dimethylhexenes is described. A method of making p-xylene using one or more 2,5-dimethylhexenes is also described.
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Paragraph 0052
(2015/09/23)
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- Mechanistic studies on reaction of [ReH4(η2- H2)(Cyttp)]+ with ketones to give the hydrido-oxo complex [ReH2(O)(Cyttp)]+ (Cyttp = PhP(CH2CH 2CH2PCy2)2)
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Mechanistic studies were conducted on reaction of [ReH4(η 2-H2)(Cyttp)]OTf (1(OTf); Cyttp = PhP(CH 2CH2CH2PCy2)2, OTf = O3SCF3) with ketones, both neat and in solution. Treatment of 1(OTf) with excess acetone at 60-65°C affords [ReH2(O)(Cyttp) ]OTf (2(OTf)) in high yield, nearly 1 equiv. of H2, 2 equiv. of 2-propanol, 1 equiv. of each of 4-hydroxy-4-methyl-2-pentanone (B) and 4-methylpent-3-en-2-one (C), and smaller amounts of other organic products derived by condensation or related reactions of acetone. The presence of C, apparently arising by dehydration of B, points to the formation of 1 equiv. of H2O in the reaction system. Use of acetone-d6 in conjunction with 1(OTf) gives 2(OTf) containing no deuterium, as well as 1 equiv. of each of (CD3)2CHOH/OD and (CD3) 2CDOD/OH. Reactions of 1(OTf) with cyclohexanone, including cyclohexanone-2,2,6,6-d4, under comparable conditions, give analogous results. The ketones cyclopentanone, 2-butanone, and 3-pentanone also convert 1(OTf) to 2(OTf) upon heating, as does isobutyraldehyde, but only in the presence of the stabilizer BHT. In contrast, the more robust ketones 2,4-dimethyl-3-pentanone, 2,6-dimethylcyclohexanone, and 2-adamantanone, which do not undergo condensation, failed to effect this transformation. Other organooxygen compounds, i.e., methanol, cyclohexanol, 1,2-butene oxide, cyclohexene oxide, DMSO, and Me3NO, also are ineffective. A mechanism is proposed which begins with loss of H2 by 2 to give a 16-electron [ReH4(Cyttp)]+ which, depending on the experimental conditions, binds a solvent or ligand molecule. A [ReH 4(R2CO)(Cyttp)]+ intermediate generated in this manner reacts spontaneously by elimination of R2CHOH (containing methine hydrogen even when deuteriated ketone is used), which results from transfer of two hydride ligands to coordinated ketone. Continued reaction leads to the formation of 2 and another molecule of R2CHOH (containing methine deuterium when deuteriated ketone is employed), with the added hydrogens coming from H2O, which derives from solvent/reactant ketone.
- Rende, Dean E.,Wojcicki, Andrew
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p. 862 - 873
(2007/10/03)
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- PRODUCTS FORMED IN REACTIONS OF ALIPHATIC ALCOHOLS WITH CO AND H2 IN PRESENCE OF COBALT CARBONYLS.
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The purpose of this work was to identify the products of conversion of aliphatic alcohols (specifically, butyl alcohols) in the course of production of cobalt carbonyls in suspensions of cobalt carbonate, and also to study the dependence of the yield of these products on the conditions of the carbonylation reactions. It was found that variation of the CO//2:H//2 ratio (from 3:1 to 1:2. 3) has no significant influence on the yield of by-products of carbonyl formation, which was 0. 7-1. 2 mass % in all experiments. Increase of temperature (to 180 degree ) and of the reaction time (to 4-6 h) leads to some increase of the by-products yield (1. 2-1. 7 mass %), mainly owing to increase of the amount of water formed, and to some extent of the amount of isobutyraldehyde. However, it must be pointed out that the by-products obtained during carbonyl formation can subsequently be converted into the required compounds during use of alcoholic solutions of cobalt carbonyls in the course of hydroformylation of olefins. These products are undoubtedly aldehydes, formates, and acetals.
- Del'nik,Kagna,Katsnel'son,Rabinovich,Skop,Churakov
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p. 2183 - 2188
(2007/10/02)
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