1004960-00-2Relevant articles and documents
Furan ring opening-indole ring closure: SnCl2-induced reductive transformation of difuryl(2-nitroaryl)methanes into 2-(2-acylvinyl)indoles
Uchuskin, Maxim G.,Molodtsova, Natalia V.,Abaev, Vladimir T.,Trushkov, Igor V.,Butin, Alexander V.
experimental part, p. 4252 - 4258 (2012/07/14)
A simple and efficient method for the synthesis of 2-(2-acylvinyl)-3-(5- alkyl-2-furyl)indoles by reductive recyclization of bis(5-alkyl-2-furyl)(2- nitroaryl)methanes is reported. This transformation was carried out by heating the substrates with SnClsu
Synthesis of tetracyclic system of 2,4-di(tert-butyl)-6,7- dihydrofuro[2′,3′:3,4]cyclohepta[1,2-b]indole
Butin, Alexander V.,Kostyukova, Olga N.,Tsiunchik, Fatima A.,Uchuskin, Maxim G.,Serdyuk, Olga V.,Trushkov, Igor V.
scheme or table, p. 684 - 690 (2011/07/07)
For the first time, tetracyclic compounds, namely, furo[2′,3′: 3,4]cyclohepta[1,2-b]indoles were synthesized by recyclization of ortho-substituted aryldifurylmethanes containing tert-butyl groups at C5 positions of the furan rings. It was shown that [2-(b
Recyclization of (2-aminophenyl)bis(5-tert-butyl-2-furyl)methanes into indole derivatives: Unusual dependence on substituent at nitrogen atom
Butin, Alexander V.,Smirnov, Sergey K.,Tsiunchik, Fatima A.,Uchuskin, Maxim G.,Trushkov, Igor V.
experimental part, p. 2943 - 2952 (2009/04/07)
The recyclization of (2-aminophenyl)bis(5-tert-butyl-2-furyl)methanes under acidic conditions was studied. It was found that the extent of reaction of these substrates depends on the substituent at the nitrogen atom of the aniline moiety. N-Tosyl derivatives were converted into the corresponding 3-(5-tert-butyl-2-furyl)-2-(4,4-dimethyl-3-oxopentyl)-1-tosyl-1H-indoles. Indole formation was followed by furan ring opening in the case of N-unsubstituted substrates leading to 3-(5,5-dimethyl-1,4-dioxohexyl)-2-(4,4-dimethyl-3- oxopentyl)-1H-indoles. The same products were obtained from N-acetyl derivatives. However, the behavior of the N-benzoyl analogues depends on the reaction conditions: at room temperature 1-benzoyl-3-(5-tert-butyl-2-furyl)-1H- indoles were formed, but debenzoylation and furan ring opening proceed with heating. These data and results of control experiments showed that the reaction mechanism consists of three successive steps: recyclization itself, deacylation of the resulting N-acylindole, and furan ring opening in N-unsubstituted 3-(2-furyl)indoles. The last step can be realized for N-unsubstituted indoles only, but the furan ring is stable for N-acylindoles. This was explained by transformation of N-unsubstituted 1H-indoles under the reaction conditions into 3H-indole tautomers. These tautomers can be considered as 2,5-dialkylfurans, which have much lower stability against acids than 2-aryl-5-alkylfurans. This tautomerization is impossible for N-acylindoles. The high acidic stability of 2-(5-tert-butyl-2-furyl)indoles supports this conclusion. Georg Thieme Verlag Stuttgart.
