New Facile Tandem Route to Oxo- and Thioxo[1,2,4]triazolo[1,5-a]pyridinium Salts

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• 作者：Roberta Palk&oacute ; Zsuzsanna Riedl ; Orsolya Egyed ; Lá ; szl&oacute ; Fá ; biá ; n ; Gy&ouml ; rgy Haj&oacute ; s
• 刊名：Journal of Organic Chemistry
• 出版年：2006
• 出版时间：September 29, 2006
• 年：2006
• 卷：71
• 期：20
• 页码：7805 - 7812
• 全文大小：145K
• 年卷期：v.71,no.20(September 29, 2006)
• ISSN：1520-6904

文摘

LE>ln00001>ls/joceah/71/i20/figures/jo061361ln00001.gif" ALIGN="left" HSPACE=5>2-Arylsulfanyl- and benzylsulfanylpyridinium N-arylimides (2), easily available from tetrazolo[1,5-b]pyridinium salts (1), participate in 1,3-dipolar cycloaddition with aryl isothiocyanates and aryl isocyanatesto result in formation of fused thioxo- and oxo[1,2,4]triazolium salts (5 and 12), respectively. Thistransformation is interpreted as a regular 1,3-cycloaddition followed by spontaneous elimination of thearyl- or benzylsulfanyl group. Formation of these triazolium salts can be followed-under appropriatereaction conditions-by ring-opening reactions to afford some new triazolyldienes (6). Recognition ofthe intermediate participation of the thiolate anion along the pathway 1 5 allowed elaboration of asimple procedure to 5 implying a tandem reaction sequence.