Synthesis of Heterocyclic Homotriptycenes

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• 作者：Hong Zhang ; Derong Cao ; Wenjie Liu ; Huanfeng Jiang ; Herbert Meier
• 刊名：Journal of Organic Chemistry
• 出版年：2011
• 出版时间：July 15, 2011
• 年：2011
• 卷：76
• 期：14
• 页码：5531-5538
• 全文大小：920K
• 年卷期：v.76,no.14(July 15, 2011)
• ISSN：1520-6904

文摘

A series of novel heterocyclic homotriptycenes bearing furan, thiophene, and pyridine rings, 7a鈥?b>f, were synthesized by intramolecular dehydration reactions of 10,10-dihetarylmethyl-9,10-dihydroanthracen-9-ols 6a鈥?b>f. In the presence of acids, the secondary alcohols 6a鈥?b>f show different reactions which depend on the electron densities of the attached heterocyclic rings. The initially formed carbenium ions react in an electrophilic substitution with electron-rich heterocycles. The formation of a transannular bridge (1,7-elimination) leads to homotriptycenes in high yields. When the heterocyclic ring has a moderate electron density, two competitive reactions exist, which afford 9-monosubstituted anthracenes by 1,4-elimination or 9,10-disubstituted anthracenes by a rearrangement, respectively. Electron-deficient heterocycles undergo a disproportionation to give hydrocarbons and ketones.