Preparation of Pentafluorosulfanyl (SF_5) PyrroleCarboxylic Acid Esters

摘要

Pyrrole derivatives bearing a pentafluorosulfanyl groupare currently unknown. In this paper, a facile preparationof SF_5-substituted pyrrole carboxylic acid esters in goodyield is reported. Utilizing the cycloaddition of an azo-methine ylide to pentafluorosulfanylalkynes, a series ofdihydropyrroles were prepared and oxidized to the re-spective 1-tert-butyl-4-(pentafluorosulfanyl)pyrrole-2-carboxylic acid esters in good yield. Further treatmentof these pyrroles with catalytic triflic acid allowed re-moval of the tert-butyl group.