- Bromination of 1,1-diarylethylenes with bromoethane
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Aliphatic bromide was used as a halogenation reagent in the presence of DMSO, resulting in 2,2-diarylvinyl bromides from the corresponding 1,1-diarylethylenes. This protocol not only provides a convenient and straightforward strategy for the rapid construction of various 2,2-diarylvinyl bromides without bromine and extra oxidants, but also can improve the atom economy of Kornblum oxidative reaction.
- Yu, Ze,Jiang, Jialiang,Chen, Hongtai,Tang, Xiangyang
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supporting information
p. 2544 - 2552
(2021/07/06)
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- A novel (2,2-diarylvinyl)phosphine/palladium catalyst for effective aromatic amination
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A new series of diarylvinylphosphine ligands was designed and synthesized. A catalyst system, consisting of the ligands and palladium species, effectively catalyzed the coupling reaction of aryl bromides and chlorides with amines to afford the corresponding products in good to excellent yields. The efficiency is likely derived from an interaction between the palladium center and the cisaryl moiety on the diarylvinylphosphine ligand stabilizing a catalytic intermediate during the coupling reaction.
- Suzuki, Ken,Hori, Yoji,Nishikawa, Takenobu,Kobayashi, Tohru
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p. 2089 - 2091
(2008/09/18)
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- 2,2-(Diaryl)vinylphosphine compound, palladium catalyst thereof, and process for producing arylamine, diaryl, or arylalkyne with the catalyst
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A novel 2,2-(diaryl)vinylphosphine compound represented by the following general formula (1): (wherein R1 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alicyclic group having 5 to 7 carbon atoms, etc.; R2, R3, R4, R5, R6, and R7 may be the same or different and each is an alkyl group having 1 to 6 carbon atoms, an alicyclic group having 5 to 7 carbon atoms, etc., provided that R4 and R5 taken together and/or R6 and R7 taken together may represent a fused benzene ring, a substituted fused benzene ring, a trimethylene group, etc.; and p, q, r, and s each is 0 to 5, provided that p+q and r+s each is in the range of from 0 to 5); a palladium-phosphine catalyst obtained by causing a palladium compound to act on the novel 2,2-(diaryl)vinylphosphine compound; and a process for obtaining an arylamine, a diaryl and an arylalkyne in the presence of the palladium-phosphine catalyst.
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- Formation and rearrangement of gem-dilithiodiphenylethene
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1,1-Dilithio-2,2-diphenylethene (14) is accessible through double bromine lithium exchange reaction starting from 1,1-dibromo-2,2-diphenylethene (5) with lithium metal at -110°C. 14 undergoes rearrangement into (E)-1-lithio-2-(2-lithiophenyl)-2-phenylethene (13) at temperatures above -100°C. The (Z)-compound 15 was formed from the (E)-compound 13 at temperatures above -25°C.
- Maercker, Adalbert,Boes, Benno,Hajgholipour, Mohammad Taghi
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p. 143 - 149
(2007/10/03)
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- Dehydrobromination of 1,1-diaryl-1,2-dibromoalkanes catalyzed by iron and iron bromides. An ion-pair-mediated reaction?
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The participation of ion-paired Lewis acid/Lewis base in the dehydrohalogenations of 1,2-dibromo-1,1-diarylalkanes catalyzed by Fe0 and by Fe(II) and Fe(III) bromides was investigated.The reactivities of the catalyst employed were correlated with their chemical hardness.The influence of para substituents on the phenyl rins of the substrates and the results obtained in Lewis-acid-catalyzed and thermal dehydrobromination of the same compounds were compared.The experimental results could not be explained in terms of a Lewis-acid-catalyzed dehydrobromination.Key words: dehydrohalogenation, bromoalkanes, Lewis acid catalysts, ion-pair mechanism.
- Suarez, Angela R.,Suarez, Alejandra G.,Martin, Sandra E.,Mazzieri, Maria R.
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