- Oxidative 1,2-Difunctionalization of Ethylene via Gold-Catalyzed Oxyarylation
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Under the conditions of oxidative gold catalysis, exposure of ethylene to aryl silanes and alcohols generates products of 1,2-oxyarylation. This provides a rare example of a process that allows catalytic differential 1,2-difunctionalization of this feedstock chemical.
- Harper, Matthew J.,Emmett, Edward J.,Bower, John F.,Russell, Christopher A.
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supporting information
p. 12386 - 12389
(2017/09/22)
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- Photocatalytic nucleophilic addition of alcohols to styrenes in Markovnikov and anti-Markovnikov orientation
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The nucleophilic addition of methanol and other alcohols to 1,1-diphenylethylene (1) and styrene (6) into the Markovnikov- and anti-Markovnikov-type products was selectively achieved with 1-(N,N-dimethylamino)pyrene (Py) and 1,7-dicyanoperylene-3,4:9,10-tetracarboxylic acid bisimide (PDI) as photoredox catalysts. The regioselectivity was controlled by the photocatalyst. For the reductive mode towards the Markovnikov-type regioselectivity, Py was applied as photocatalyst and triethylamine as electron shuttle. This approach was also used for intramolecular additions. For the oxidative mode towards the anti-Markovnikov-type regioselectivety, PDI was applied together with Ph-SH as additive. Photocatalytic additions of a variety of alcohols gave the corresponding products in good to excellent yields. The proposed photocatalytic electron transfer mechanism was supported by detection of the PDI radical anion as key intermediate and by comparison of two intramolecular reactions with different electron density. Representative mesoflow reactor experiments allowed to significantly shorten the irradiation times and to use sunlight as "green"light source.
- Weiser, Martin,Hermann, Sergej,Penner, Alexander,Wagenknecht, Hans-Achim
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p. 568 - 575
(2015/06/08)
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- Indium triiodide catalyzed direct hydroallylation of esters
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The InI3-catalyzed hydroallylation of esters by using hydroand allysilanes under mild conditions has been accomplished. Many significant groups such as alkenyl, alkynyl, cyano, and nitro ones survive under these conditions. This reaction system, provided routes to both homoallylic alcohols and ethers, in which either elimination of the alkoxy moiety or of the carbonyl oxygen atom could be freely selected by changing the substituents on the alkoxy moiety and on the hydrosilane. In addition, the hydroallylation of lactones took place without ring cleavage to produce the desired cyclic ethers in high yields.
- Nishimoto, Yoshihiro,Inamoto, Yoshihiro,Saito, Takahiro,Yasuda, Makoto,Baba, Akio
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supporting information; experimental part
p. 3382 - 3386
(2010/08/19)
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- Gold-catalyzed substitution reaction with ortho-alkynylbenzoic acid alkyl ester as an efficient alkylating agent
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ortho-Alkynylbenzoic acid alkyl esters behave as alkylating agents in combination with gold catalysts. The reaction with alcohols occurs smoothly in the presence of catalytic amounts of Ph3PAuCl and AgOTf under mild conditions to produce the corresponding ether products in high yields. The protocol is also useful for Friedel-Crafts alkylation and N-alkylation of sulfonamides. The reaction likely proceeds through the gold-induced in situ construction of leaving groups and subsequent nucleophilic attack of nucleophiles, such as alcohols, aromatic compounds, and sulfonamides.
- Aikawa, Haruo,Tago, Sakie,Umetsu, Kazuteru,Haginiwa, Naomichi,Asao, Naoki
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experimental part
p. 1774 - 1784
(2009/06/20)
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- Gold-catalyzed etherification and friedel - Crafts alkylation using ortho-alkynylbenzoic acid alkyl ester as an efficient alkylating agent
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A gold-catalyzed alkylation of alcohols and aromatic compounds is described. The reaction of ortho-alkynylbenzoic acid alkyl esters with alcohols or aromatic compounds occurs in the presence of catalytic amounts of Ph 3PAuCl and AgOTf under mild conditions to produce corresponding ethers or Friedel-Crafts alkylation products in good to high yields. The reaction likely proceeds through the gold-induced in situ construction of leaving groups and subsequent nucleophilic attack of alcohols or aromatic compounds.
- Asao, Naoki,Aikawa, Haruo,Tago, Sakie,Umetsu, Kazuteru
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p. 4299 - 4302
(2008/02/12)
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- Etherification of alkoxydialkylsilanes with carbonyl compounds
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A novel method for preparing ethers from alkoxydialkylsilanes and carbonyl compounds through reductive etherification is described. The salient feature in this method is the utilization of internal hydrogen as the hydride source for reducing the oxonium intermediate generated by using the Cl(R)2SiBr[BiBr3/Cl(R)2SiH] catalytic system.
- Jiang, Xinglong,Bajwa, Joginder S,Slade, Joel,Prasad, Kapa,Repi?, Oljan,Blacklock, Thomas J
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p. 9225 - 9227
(2007/10/03)
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- PHOTOLYSIS OF 2-PHENYLETHYL AND 4-PHENYL-1-BUTYL HALIDES IN ALCOHOLIC SOLVENTS
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Photolysis of 2-phenylethyl bromide in the lower alcohols gave the corresponding carbinols and ethers as the main products.With 2-phenylethyl iodide, the products were almost exclusively of the latter type, while 4-phenyl-1-butyl halides gave n-butylbenzene, 4-phenyl-1-butene and tetralin.It is shown that each of these products may be assigned to an ionic or radical pathway and that both the nature of the sovent and the structure of the substrate affect the course of photolysis.There is a substrate dependent preference for specific reactions along pathways of both the radical and ionic types.The variations in product composition and distribution are rationalized in terms of the relative efficiencies furnished in these pathways for the relaxation of high energy intermediates produced in the initial stages of photolysis.Intervention by the phenyl group is more pronunced in the case of 2-phenylethyl halides than in the case of the higher homologues and more effective in the ionic pathway.
- Bhalerao, V. K.,Nanjundiah, B. S.,Sonawane, H. R.,Nair, P. M.
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p. 1487 - 1496
(2007/10/02)
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