- Glaser oxidative coupling in ionic liquids: An improved synthesis of conjugated 1,3-diynes
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Terminal alkynes undergo oxidative-coupling smoothly in the presence of the CuCl-TMEDA catalytic system in hydrophobic [bmim]PF6 ionic liquid under aerobic conditions to produce 1,3-diynes in excellent yields under mild conditions. The substrates, alkynes, show enhanced reactivity and selectivity in ionic liquids (ILs). The recovery of the catalyst is facilitated by the hydrophobic nature of the [bmim]PF6 ionic liquid.
- Yadav,Reddy,Reddy, K. Bhaskar,Gayathri, K. Uma,Prasad
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p. 6493 - 6496
(2007/10/03)
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- Solution-Spray Flash Vacuum Pyrolysis: A New Method for the Synthesis of Linear Poliynes with Odd Numbers of CC Bonds from Substituted 3,4-Dialkynyl-3-cyclobutene-1,2-diones
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We report a new method for the preparation of a wide range of linear poliynes, 1a-1i, with an odd number of CC bonds.This method is based on solution-spray flash vacuum pyrolysis (SS-FVP) of the readily available 3,4-dialkynyl-3-cyclobutene-1,2-diones 3a-3i.It allows the synthesis of multigram quantities of a series of hexatriynes and decapentaynes from poorly volatile and thermally unstable precursors that cannot be subjected to conventional flash vacuum pyrolysis.Yields of the linear poliynes range from 42 to 99percent.Similarly, the dodecahexayne 1j was obtained in31percent yield by SS-FVP of the bis(3-cyclobutene-1,2-dione) 3j.The synthesis of the new 3,4-dialkynyl-3-cyclobutene-1,2-diones 3h-3j via the ketals 7, 10, and 13 is reported.The X-ray crystal structure of 1,10-diphenyl-1,3,5,7,9-decapentayne (1c) was solved, and the crystal packing structure provides valuable information to explain the thermal polymerization behavior observed for this compound in the crystalline state.
- Rubin, Yves,Lin, Sophia S.,Knobler, Carolyn B.,Anthony, John,Boldi, Armen M.,Diederich, Francois
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p. 6943 - 6949
(2007/10/02)
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