A Radical Access to CF3- and SF5-Containing Dihydrobenzofurans and IndolinesThis work was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC), the Fonds de recherche du Québec – Nature et technologies (FRQNT), the FRQNT Centre in Green Chemistry and Catalysis (CCVC), and the Université Laval.
Received: 29 August 2017
Accepted: 05 September 2017
04 October 2017 (eFirst)
‡ These authors contributed equally to this work.
The synthesis of 3-(2,2,2-trifluoroethyl)-2,3-dihydrobenzofurans, 3-(2,2,2-trifluoroethyl)indolines, 3-[(pentafluorosulfanyl)methyl]-2,3-dihydrobenzofurans, and 3-[(pentafluorosulfanyl)methyl]indolines using an intramolecular reductive radical cyclization from readily available acyclic precursors is reported. The CF3- and SF5-containing heterocycles are obtained in moderate to excellent yields. Notably, this transformation represents the first example of an aryl radical addition to a SF5-containing alkene. Finally, the possibility of oxidation of some of the products generated to benzofurans and indoles is shown.