- Reactions of Oxygenated Radicals in the Gas Phase. Part 7. Reactions of Methylperoxyl Radicals and Alkenes
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The reactions of methylperoxyl radicals with alkenes have been studied between 373 and 403 K.The peroxyl radicals were generated by the oxidation of di-t-butyl peroxide.Arrhenius parameters for reaction (18) have been determined for 2-meth
- Osborne, David A.,Waddington, David J.
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- Synthesis and Structure of Tin and Germanium Complexes as Precursors Containing Alkoxyaminoalkoxide Ligands for Thin Film Transistors
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This paper describes the preparation of four novel Sn and Ge complexes containing alkoxyaminoalkoxide type ligands {L1H = 1-[methoxy(methyl)amino]-2-methylpropan-2-ol; L2H = 1-[methoxy(methyl)amino]-2-methylbutan-2-ol} for potential use as precursors for thin film transistors. All compounds were prepared at room temperature by stirring a solution containing Sn(btsa)2 [btsa = bis(trimethylsilyl)amide] or Ge(btsa)2 with two equivalents of L1H or L2H to form Sn(L1)2 (1), Sn(L2)2 (2), Ge(L1)2 (3) and Ge(L2)2 (4). All of the complexes were characterized by NMR and FTIR spectroscopy as well as elemental and thermogravimetric analyses. When the more symmetric and compact ligand L1H was applied, solid products 1 and 3 were generated and their structures were studied using X-ray diffraction. Applying the strategy of ligand design at the molecular level, the symmetric ligand was changed to an asymmetric one, replacing one of the two neighboring methyl groups of the amino alcohol group with an ethyl group, and forming liquid complexes 2 and 4 for both metals.
- Chung, Taek-Mo,Han, Seong Ho,Jeon, Dong Ju,Kim, Chang Gyoun,Lee, Ga Yeon,Lee, Ji Hun,Park, Bo Keun,Son, Seung Uk
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- Reactions of Oxygenated Radicals in the Gas Phase. Part 15. Reactions of t-Butylperoxyl Radicals with Alkenes
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The photo-oxidation of mixtures of trans-2,2'-azoisobutane and some aliphatic alkenes has been studied between 313 and 393 K.Rate constants for the reaction between t-butylperoxyl radicals with ethene, 2-methylpropene, 2-methylbut-1-ene, 2-methylbut-2-ene, and 2,3-dimethylbut-2-ene have been determined at 393 K.Arrhenius parameters for the reaction (22) have been determined for 2-methylbut-2-ene and 2,3-dimethylbut-2-ene.They are log (A22/dm3mol-1s-1) of 8.16+/-0.38 and 8.58+/-0.61, and E22/kJ mol-1 of 56.6+/-2.4 and 48.7+/-4.1, respectively.The data obtained in this work are compared with that obtained for the series hydroperoxyl, and isopropylperoxyl radicals, and with rate data obtained for the addition reaction between alkenes and peracetyl radicals.
- Morgan, Morag E.,Osborne, David A.,Waddington, David J.
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- SYSTEMS AND METHODS FOR REGIOSELECTIVE CARBONYLATION OF 2,2-DISUBSTITUTED EPOXIDES
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Provided are methods of carbonylating cyclic substrates to produce carbonyl ated cyclic products. The cyclic substrates may be 2, 2-di substituted epoxides and the cyclic products may be β,β-di substituted lactones. The method may be carried out by forming and pressurizing a reaction mixture of the cyclic substrate, a solvent, carbon monoxide, and a [LA+][CO(CO)4-] catalyst, where [LA+] is a Lewis acid capable of coordinating to the cyclic substrate. The method may proceed with a regioselectivity of 90:10 or greater. The resulting carbonylated cyclic products may be converted to ketone aldol products that retain the stereochemistry and enantiomeric ratio of the carbonyl ated cyclic products.
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Paragraph 0146; 0151
(2020/06/05)
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- Regioselective Carbonylation of 2,2-Disubstituted Epoxides: An Alternative Route to Ketone-Based Aldol Products
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We report the regioselective carbonylation of 2,2-disubstituted epoxides to β,β-disubstituted β-lactones. Mechanistic studies revealed epoxide ring-opening as the turnover limiting step, an insight that facilitated the development of improved reaction conditions using weakly donating, ethereal solvents. A wide range of epoxides can be carbonylated to β-lactones, which are subsequently ring-opened to produce ketone-based aldol adducts, providing an alternative to the Mukaiyama aldol reaction. Enantiopure epoxides were demonstrated to undergo the carbonylation/ring-opening process with retention of stereochemistry to form enantiopure β-hydroxy esters.
- Hubbell, Aran K.,Lapointe, Anne M.,Lamb, Jessica R.,Coates, Geoffrey W.
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supporting information
p. 2474 - 2480
(2019/02/14)
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- Reactivity and kinetic-mechanistic studies of regioselective reactions of rhodium porphyrins with unactivated olefins in water that form β-hydroxyalkyl complexes and conversion to ketones and epoxides
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This article reports on the selective oxidation of unactivated alkenes to ketones and epoxides through the intermediacy of β-hydroxyalkyl rhodium porphyrin complexes which are formed by reactions of terminal alkenes with tetra(p-sulfonatophenyl)porphyrin
- Zhang, Jiadi,Wayland, Bradford B.,Yun, Lin,Li, Shan,Fu, Xuefeng
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scheme or table
p. 477 - 483
(2010/04/04)
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- Dissociation of Positively Charged Aliphatic Epoxides. II. +. Epoxides and α,β Unsaturated Ethers
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The unimolecular dissociations of C5 epoxides ions mono- or disubstituted at C1 give exclusive loss of CH3 and exclusive formation of methoxyvinyl carbenium ion, both in the source and in the 2nd field-free region.In the case of the 1,2-disubstituted ion in the 2nd field-free region the loss of ethene is the only pathway, while a competition occurs for the trisubstituted ion leading to +. and +. ions, the structure of which are demonstrated.The first step of the different mechanisms is the cleavage of the heterocyclic C-C bond.
- Bouchoux, Guy,Djazi, Feycal,Hoppilliard, Yannik,Jaudon, Pascale,Nouts, Nathalie
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- Reactions of Oxygenated Radicals in the Gas Phase. Part 12. The Reactions of Isopropylperoxyl Radicals and Alkenes
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The co-oxidation of trans-2,2'-azopropane and some aliphatic alkenes has been studied between 303 and 408 K.From the yields of molecular products, rate data have been obtained for the reaction of isopropylperoxyl radicals and the following alkenes, 2-methylbut-2-ene, 2-methylbut-1-ene, 2-methyl-propene, propene, and 3-fluoropropene (reaction (22)).It is shown that the isopropylperoxyl radical is less reactive than methylperoxyl but still shows distinct electrophilic character in these reactions.
- Sway, Mohammed I.,Waddington, David J.
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p. 139 - 144
(2007/10/02)
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2-Halogenoalkoxytributyltin compounds have been prepared from tributylethoxytin and 1,2-halohydrins. The thermal degradation and its mechanism are investigated. These reactions offer a convenient way to prepare epoxides.
- Delmond, Bernard,Pommier, Jean-Claude,Valade, Jacques
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