- Gold(I)-Catalyzed N-Desulfonylative Amination versus N-to-O 1,5-Sulfonyl Migration: A Versatile Approach to 1-Azabicycloalkanes
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Valuable 1-azabicycloalkane derivatives have been synthesized through a novel gold(I)-catalyzed desulfonylative cyclization strategy. An ammoniumation reaction of ynones substituted at the 1-position with an N-sulfonyl azacycle took place in the presence of a gold cation by intramolecular cyclization of the disubstituted sulfonamide moiety onto the triple bond. Depending on the size of the heterocyclic ring and substitution of the substrates, two unprecedented forms of nucleophilic attack on the sulfonyl group were exploited, that is, a N-desulfonylation in the presence of an external protic O nucleophile (37–87 %, 10 examples) and a unique N-to-O 1,5-sulfonyl migration (60–98 %, 9 examples).
- Miaskiewicz, Solène,Gaillard, Boris,Kern, Nicolas,Weibel, Jean-Marc,Pale, Patrick,Blanc, Aurélien
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p. 9088 - 9092
(2016/07/26)
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- Graphite/methanesulfonic acid (GMA) as a new reagent for sulfonylation of phenols and thia-Fries rearrangement of aryl sulfonates to sulfonylphenols
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A new facile method for direct sulfonylation of phenols was developed. Graphite in methanesulfonic acid (GMA) was used to prepare sulfonylphenols by sulfonylation of phenol and naphthalene derivatives with p-toluenesulfonic acid (=4-methylbenzenesulfonic acid) (Table 1) and the thia-Fries rearrangement of aryl sulfonates (Table 4). Mechanistic studies showed that the sulfonylation reaction of phenols in GMA occurred through an initial sulfonate formation followed by a thia-Fries rearrangement of the aryl sulfonate by an intermolecular mechanism (Scheme 3).
- Sharghi, Hashem,Shahsavari-Fard, Zahra
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