- Copper-Catalyzed Hydroarylation of Internal Alkynes: Highly Regio- and Diastereoselective Synthesis of 1,1-Diaryl, Trisubstituted Olefins
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The copper-catalyzed hydroarylation of internal, unsymmeric alkynes is presented. Trisubstituted alkenes are obtained as single diastereomers in good to excellent yields and excellent regioselectivities. The scope of the reaction is presented with respect to alkyne and aryl iodide coupling partners. Initial mechanistic experiments indicate a hydrocupration event followed by a two-electron oxidative addition/reductive elimination pathway.
- Kortman, Gregory D.,Hull, Kami L.
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p. 6220 - 6224
(2017/09/15)
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- Electro-reductive cyclization of aryl halides promoted by fluorene derivatives
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In the presence of fluorene derivatives, the electro-reduction of aryl chlorides, bromides, and iodides bearing an ethylene moiety proceeded smoothly to afford the corresponding cyclized products. Noteworthy is that aryl chlorides, which have more negative reduction potential than aryl bromides and iodides, exhibited high reactivity in the reaction, and the corresponding five-membered and six-membered cyclized products were obtained in good to high yields. Mechanistic study suggests that the electro-reduction of fluorene derivatives was essential for the reactions, indicating that they work as a mediator.
- Mitsudo, Koichi,Nakagawa, Yumiko,Mizukawa, Jun-Ichi,Tanaka, Hideo,Akaba, Ryoichi,Okada, Takahiro,Suga, Seiji
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p. 444 - 449
(2012/11/07)
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- Hybrid super electron donors - Preparation and reactivity
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Neutral organic electron donors, featuring pyridinylidene-imidazolylidene, pyridinylidene-benzimidazolylidene and imidazolylidene-benzimidazolylidene linkages are reported. The pyridinylidene-benzimidazolylidene and imidazolylidene-benzimidazolylidene hyb
- Garnier, Jean,Thomson, Douglas W.,Zhou, Shengze,Jolly, Phillip I.,Berlouis, Leonard E. A.,Murphy, John A.
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supporting information; experimental part
p. 994 - 1002
(2012/09/08)
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- Intramolecular photoarylation of alkenes by phenyl cations
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Acetone-sensitized irradiation of various o-chlorophenyl allyl ethers in polar solvents led to either (dihydro)benzofurans or chromanes. The reaction appeared to involve photoheterolysis of the aryl-Cl bond followed by phenyl cation addition onto the tethered double bond either in 5-exo or 6-endo modes. The adduct cation gave the end products by deprotonation: addition of chloride anion or of the solvent, depending on the struc ture: and the conditions used. Preference for the 5-exo mode increased in passing from medium polarity (methylene chloride, ethyl acetate) to high polarity solvents (aqueous acetonitrile, methanol, 2,2,2-trifluoroethanol), for which this was often the exclusive path. The same compounds underwent photohomolysis when irradiated in cyclohexane, and radical cyclization was one of the process occurring. Substitution of a methylene group for the ether oxygen atom made 6-endo cyclization by far the main path in a related o-chlorophenylbutene. Again, the selectivity was higher in polar protic solvents. The results are discussed in terms of in cage ion pair versus free phenyl cation reactions.
- Dichiarante, Valentina,Fagnoni, Maurizio,Mella, Mariella,Albini, Angelo
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p. 3905 - 3915
(2008/02/06)
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