Use of 1,3-dipolar reactions for the preparation of SF sub(5-substituted five-membered ring heterocycles. Pyrroles and thiophenes)

• Published in: Journal of fluorine chemistry Vol. 132; no. 6; pp. 389 - 393
• Main Authors: Dolbier, William R, Zheng, Zhaoyun
• Format: Journal Article
• Language: English
• Published: 01-06-2011
• Subjects: Aromatic compounds; Cycloaddition; Fluorine; Parents; Pyrroles; Synthesis (chemistry); Thiophenes
• ISSN: 0022-1139
• DOI: 10.1016/j.jfluchem.2011.03.017

In situ-generated unsubstituted, "parent" azomethine and thiocarbonyl ylides are used to prepare a large variety of 3-aryl- and alkyl-substituted, 4-pentafluorosulfanylpyrroles and 3-aryl-substituted, 4-pentafluorosulfanylthiophenes, the latter of which are to our knowledge the first reported SF sub(5-substituted thiophenes. The 1,3-cycloadditions of these ylides with aryl and alkyl, SF) sub(5)-alkynes produce dihydro-pyrroles and thiophenes, which without isolation can then be oxidatively aromatized to the respective pentafluorosulfanylpyrroles and thiophenes in good yield. Synthesis of pentafluorosulfanyl pyrroles and thiophenes via 1,3-dipolar cycloadditions of azomethine ylide and thiocarbonyl ylide.[inline image]