- Highly stereoselective approach to 3-fluoroalkylated (E)-hex-3-ene-1,5- diyne derivatives via an addition-elimination reaction
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Palladium(0)-catalyzed Sonogashira cross-coupling reaction of 2-fluoroalkylated (Z)-2-fluoro-1-iodoethene, which is easily prepared from commercially available polyfluorinated alcohols in facile three steps, with terminal alkynes in DMF at room temperature for 24 h took place stereospecifically to give the corresponding 1-fluoroalkylated (Z)-1-fluorobut-1-en-3-yne derivatives in good to excellent yield. Thus obtained fluoroalkylated 1-fluoroenynes were effectively subjected to addition-elimination reaction with various alkynyllithiums at room temperature, leading to 3-fluoroalkylated hex-3-ene-1,5-diyne derivatives in good to high yields with an excellent E selectivity.
- Konno, Tsutomu,Kishi, Misato,Ishihara, Takashi,Yamada, Shigeyuki
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p. 144 - 151
(2013/11/19)
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- Facile syntheses of various per- or polyfluoroalkylated internal acetylene derivatives
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Treatment of per- or polyfluoroalkylated vinyl iodides 5 with 2equiv. of n-BuLi in THF produced the corresponding lithium acetylides in situ, which were transformed into zinc acetylides by the addition of ZnCl2· TMEDA complex into the reaction mixture. The in situ generated zinc acetylides were exposed to the cross-coupling conditions such as ArI/cat. Pd(PPh 3)4, reflux, 6-12 h, giving rise to the desired per- or polyfluoroalkylated acetylenes in high yields. In the case of trifluoromethylated acetylene, commercially available 2-bromo-3,3,3-trifluoropropene 6 could also be used instead of 5 as the starting material. In the acetylenes having a fluoroalkyl group and an aliphatic side chain, vinyl iodides 7, prepared by radical addition of perfluoroalkyl iodide to terminal acetylenes, were treated with t-BuOK at room temperature or at the reflux temperature of benzene, affording the desired compounds in good yields.
- Konno, Tsutomu,Chae, Jungha,Kanda, Masashi,Nagai, Go,Tamura, Kazushige,Ishihara, Takashi,Yamanaka, Hiroki
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p. 7571 - 7580
(2007/10/03)
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- 1-Iodo-polyfluoroalkanes from polyfluoroalkoxy trimethylsilanes and iodochloro triphenylphosphorane
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Polyfluoroalkoxy trimethylsilanes R(f)CH2OSi(CH3)3 (from the alcohols R(f)CH2OH and HMDS), react with Pb3PICI (from ICI and Ph3P) eliminating (CH3)3SiCl. Pyrolysis of the residues gives Ph3PO and pure iodides R(f)CH2I.
- Montanari,Quici,Resnati
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p. 1941 - 1944
(2007/10/02)
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