An approach to 2, 3-dihydropyrroles and β-iodopyrroles based on 5-endo-dig cyclisations

DW Knight, AL Redfern, J Gilmore

Index: Knight, David W.; Redfern, Adele L.; Gilmore, Jeremy Journal of the Chemical Society. Perkin Transactions 1, 2002 , # 5 p. 622 - 628

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Citation Number: 80

Abstract

A representative series of homopropargylic sulfonamides 19 and 22b have been found to undergo smooth 5-endo-dig cyclisation upon exposure to excess iodine in acetonitrile containing potassium carbonate. The resulting 4-iodo-2, 3-dihydropyrroles 23 readily react with two equivalents of DBU in DMF at 20° C to give the corresponding β-iodopyrroles 24 and 26 in excellent yields by the elimination of toluene-p-sulfinic acid. Use of less than two ...