- CoCl2 catalyzed trifluoroacetylation versus dimerization of methoxyaromatics using trifluoroacetic anhydride
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Anisole, resorcinol dimethyl ether, p methylanisole, and β- methoxynaphthalene undergo regiospecific trifluoroacetylation in neat influoroacetic anhydride (TFAA) at 100 °C in the presence of 0.1 eq. CoCl2 as catalyst, with a 1:1 anisole/TFAA ra
- Ruiz, Jaime,Astruc, Didier,Gilbert, Laurent
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Read Online
- Metal-free defluorinative arylation of trifluoromethyl alkenes: Via photoredox catalysis
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Literature methods to access gem-difluoroalkenes are largely limited to harsh, organometallic-based methods, and known photoredox-mediated processes are not amenable to aryl radical addition to trifluoromethyl alkenes. A metal-free, functional group-tolerant method for the preparation of benzylic gem-difluoroalkenes is described. Halogen atom abstraction from (hetero)aryl halides generates aryl radicals that undergo a defluorinative arylation of α-trifluoromethyl alkenes, tolerating electronically disparate aryl radicals and α-trifluoromethyl alkenes.
- Wiles, Rebecca J.,Phelan, James P.,Molander, Gary A.
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supporting information
p. 7599 - 7602
(2019/07/05)
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- Catalytic asymmetric hydrogenation of α-CF3- or β-CF3-Substituted acrylic acids using Rhodium(I) complexes with a combination of chiral and achiral ligands
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Only the mixture works! Acrylic acid derivatives with CF3 substituents in α or β position were efficiently hydrogenated in the presence of a RhI complex with a chiral secondary phosphine oxide (SPO; see scheme) and an achiral Ph3P as ligands. The corresponding propanoic acid derivatives were obtained with generally high conversion (>99 %) and high enantioselectivity (92->99 %). Copyright
- Dong, Kaiwu,Li, Yang,Wang, Zheng,Ding, Kuiling
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supporting information
p. 14191 - 14195
(2014/01/06)
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- Synthesis, and cyclization to aurones and flavones, of alkoxy-substituted aryl, arylalkynyl ketones
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Acylation of 1,3,5-tribenzyloxybenzene with alkoxy-substituted phenylpropioloyl chlorides provides the corresponding aryl alkoxylarylalkynyl ketones in which one of the benzyl groups has been removed. Cyclization of these phenolic ketones using basic reagents (potassium carbonate in acetone is best) provides the corresponding aurone system. When the phenolic group of the alkynyl ketones is protected as the t-butyldimethylsilyl ether followed by cyclization, using 18-crown-6 and potassium fluoride, mixtures of the corresponding aurones and flavones are produced. A by-product from the formation of the ketones is the corresponding β-chlorochalcone, which can also be cyclized to an aurone product using basic conditions. Similarly, the t-butyldimethylsilyl ethers of the HCl adducts can also be cyclized to a mixture of the corresponding aurones and flavones. CSIRO 2008.
- Kerr, Penelope J.,Pyke, Simon M.,Ward, A. David
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p. 350 - 358
(2008/09/19)
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