SnCl 4 -mediated oxidative biaryl coupling reaction of 1-naphthol and subsequent ring closure of 2,2′-binaphthol to the dinaphthofuran framework

Autor: Tokutaro Ogata, Tetsuya Takeya, Hirohisa Doi, Tsuyoshi Otsuka, Iwao Okamoto, Eiichi Kotani
Rok vydání: 2004
Předmět:
Zdroj: Tetrahedron. 60:6295-6310
ISSN: 0040-4020
DOI: 10.1016/j.tet.2004.05.077
Popis: A simple method for the direct synthesis of 2,2′-binaphthols 2 and dinaphtho[1,2-b;2′,1′-d]furans 3 under mild conditions was developed, utilizing a biaryl coupling reaction via electron donor–acceptor complexes of 1-naphthols with SnCl4. Heating of the complex in a sealed tube for (18–24 h) afforded the corresponding o–o coupled product 2 in excellent yield. Prolonged reaction (56–65 h) under the same conditions afforded 3 in high yield in one step. We also found that in the case of α-naphthol without substituents other than a hydroxyl group at the C-1 position, regioselective o–o coupling reaction proceeded. The products 2a, 2b and 2g should be useful as synthetic intermediates for naturally occurring 3,3′-bijuglone, 3,3′-biplumbagin and elliptinone.
Databáze: OpenAIRE