Tin-Free Radical Cyclizations for the Synthesis of 7-Azaoxindoles, 7-Azaindolines, Tetrahydro[1,8]naphthyridines, and Tetrahydro-5<i>H</i>-pyrido[2,3-<i>b</i>]azepin-8-ones
作者:Eric Bacqué、Myriem El Qacemi、Samir Z. Zard
DOI:10.1021/ol0489649
日期:2004.10.1
Compounds containing a pyridine nucleus fused to a saturated nitrogen-containing ring, including 7-azaoxindoles, 7-azaindolines, tetrahydro-[1,8]naphthyridines, and tetrahydro-5H-pyrido[2,3-b]azepin-8-ones, were prepared in good yield starting from various 2,6-dichloropyridines. The method hinges on a free-radical xanthate-mediated cyclization or intermolecular addition/cyclization sequence for the construction of the new fused rings.