111409-80-4Relevant academic research and scientific papers
Photochemical Unmasking of Polyyne Rotaxanes
Woltering, Steffen L.,Gawel, Przemyslaw,Christensen, Kirsten E.,Thompson, Amber L.,Anderson, Harry L.
, p. 13523 - 13532 (2020)
Bulky photolabile masked alkyne equivalents (MAEs) are needed for the synthesis of polyyne polyrotaxanes, as insulated molecular wires and as stabilized forms of the linear polymeric allotrope of carbon, carbyne. We have synthesized a novel MAE based on phenanthrene and compared it with an indane-based MAE. Photochemical unmasking of model compounds was studied at different wavelengths (250 and 350 nm), and key products were identified by NMR spectroscopy and X-ray crystallography. UV irradiation at 250 nm leads to unmasking of both MAEs. Irradiation of the phenanthrene system at 350 nm results in quantitative dimerization via [2 + 2] cycloaddition to form a [3]-ladderane; irradiation of this ladderane at 250 nm generates a dihydrotriphenylene, which can be oxidized easily to a triphenylene. Irradiation of the indane-based MAE at 350 nm in the presence of traces of oxygen forms an endoperoxide and a bisepoxide. Both MAEs have been incorporated into rotaxanes via copper-mediated active metal template Glaser or Cadiot-Chodkiewicz coupling. The identity of the rotaxanes was confirmed by NMR spectroscopy and mass spectrometry. The phenanthrene rotaxane decomposes during attempted photochemical unmasking, whereas photolysis of the indane rotaxane results in unmasking of the polyyne thread to form a rotaxane with a chain of 16 sp-hybridized carbon atoms. This approach opens avenues toward the synthesis of encapsulated carbon allotropes.
Expedient synthesis of conjugated triynesviaalkyne metathesis
Baslé, Olivier,Clermont, Anthony,Colombel-Rouen, Sophie,Curbet, Idriss,Müller, Daniel S.,Manguin, Romane,Mauduit, Marc,Quelhas, Alexandre,Roisnel, Thierry,Trolez, Yann
, p. 4934 - 4938 (2020/06/09)
The first synthesis of conjugated triynes by molybdenum-catalysed alkyne metathesis is reported. Strategic to the success of this approach is the utilization of sterically-hindered diynes that allowed for the site-selective alkyne metathesis to produce th
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
Rubin, Yves,Lin, Sophia S.,Knobler, Carolyn B.,Anthony, John,Boldi, Armen M.,Diederich, Francois
, p. 6943 - 6949 (2007/10/02)
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.
