Abstract
Three new heterocyclic parent compounds, 2,3-dihydrothieno[2,3-b ][1,4]dithiine (TDT), 2,3-dihydrothieno[3,2-b ][1,4]oxathiine (TOT), and 2,3-dihydrothieno[2,3-b ][1,4]oxathiine, have been synthesized by acid-catalyzed transformations starting from 3-methoxythiophene. Two of the new compounds have been transformed to the corresponding end-capped dimeric, trimeric and tetrameric oligothiophenes. These oligomers show very stable cationic and dicationic states as judged by cyclic voltammetry, and their UV-Vis spectra are considerably red-shifted compared to previously synthesized end-capped oligomers.
Key words
ring-closure - tandem reactions - oligothiophenes - Suzuki coupling
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2 Present address: Acreo AB, Bredgatan 34, SE-602 21 Norrköping, Sweden.
3 Present address: Unit for Organic Chemistry, Department of Biosciences, Karolinska Institute and Södertörn University College, Novum Research Park, SE-141 57 Huddinge, Sweden.
4 Present address: AstraZeneca R&D, SE-151 85 Södertälje, Sweden.
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