Tin-free radical cyclizations for the synthesis of 7-azaoxindoles, 7-azaindolines, tetrahydro[1,8]naphthyridines, and tetrahydro-5H-pyrido[2,3-b] azepin-8-ones

Eric Bacqué (1) , Myriem El Qacemi (2) , Samir Zard (2)

1 AVENTIS Pharma
2 DCSO - Laboratoire de synthèse organique

(Chemical Equation Presented) 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.

Domains: Organic chemistry

Eric Bacqué, Myriem El Qacemi, Samir Zard. Tin-free radical cyclizations for the synthesis of 7-azaoxindoles, 7-azaindolines, tetrahydro[1,8]naphthyridines, and tetrahydro-5H-pyrido[2,3-b] azepin-8-ones. Organic Letters, 2004, 6 (21), pp.3671-3674. ⟨10.1021/ol0489649⟩. ⟨hal-00954818⟩