- Generation of Dimethyl Sulfoxide Coordinated Thermally Stable Halogen Cation Pools for C?H Halogenation
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A method to generate halogen cation pools from the reaction of 1,2-dihaloethanes (hal=Br, I) and dimethyl sulfoxide (DMSO) for C?H halogenation of arenes and heteroarenes was reported. The initial reaction of DMSO and 1,2-dihaloethane generates the sulfur
- Dalai, Pallaba Ganjan,Palit, Kuntal,Panda, Niranjan
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supporting information
p. 1031 - 1038
(2022/02/02)
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- Enamines β-lithiees. I. Preparations et reactions d'alkylation
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The action of alkyllithium reagents on β-bromoenamines 1-9 quickly yields, in THF, β-lithioenamines through halogen - metal exchange.If metallic lithium is used instead of organolithium compounds, β-lithioenamines are also formed but in this case they are accompanied by small amounts of by-products.The action of alkyllithium reagents R1Li on the β-chloroenamine 10 provides a new source of β-lithioenamines in which nucleophilic insertion of the R1 group takes place. β-Lithioenamines are stable compounds even up to 20 deg C in most cases.With alkyl iodides, β-lithioenamines react vigorously even at low temperature.The reaction is stereospecific with retention of configuration.This reaction generates either β-substituted enamines or, by easy acidic hydrolysis, α-substituted carbonyl compounds.The C-alkylation reaction is observed alone.
- Duhamel, Lucette,Poirier, Jean-Marie
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p. 297 - 303
(2007/10/02)
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- Preparation of Diaryl and Aryl tert-Butyl α-Thioxoketones
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The preparation of the α-haloketones 6, 13-16, 19, and 20 is reported. 13 or its precursor, the acyloin 9, respectively, is conveniently obtained by a Seebach synthesis. - Reaction of the haloketones with tetraethylammonium thiosulfate (21) yields the Bunte salts 22-27 wich form the thioketones 28-33 on cleavage with aqueous alkali. 29 is stable as a crystalline, blue monomer in contrast with other aromatic α-thioxoketones.This ist also true for the aromatic-aliphatic derivatives 30 and 31 as well as their isomers 32 and 33 wich do not dimerize.
- Hahn, Bernd,Koepke, Brigitte,Voss, Juergen
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