Gold‐Catalyzed Synthesis of 3‐Pyrrolidinones and Nitrones from N‐Sulfonyl Hydroxylamines via Oxygen‐Transfer Redox and 1,3‐Sulfonyl Migration

Combination of gold catalysis and Selectfluor for the synthesis of fluorinated nitrogen heterocycles

“…Recently also, the literature has featured valuable access routes to pyrrolidine promoted by catalytic systems [18–26]. …”

Dissociation of protonated N‐(3‐phenyl‐2H‐chromen‐2‐ylidene)‐ benzenesulfonamide in the gas phase: cyclization via sulfonyl cation transfer

“…Namely, the sulfonyl cation is transferred to the ortho ‐site of the C‐ring, and the activated hydrogen migrates to the sulfonyl O 7‐atom, which leads to a cyclization reaction via the loss of benzenesulfinic acid . An intramolecular N ‐ to C ‐sulfonyl migration have also been reported in the condensed phase . Analogously, migration of the tosyl cation and reduction of the tosyl group have been previously reported in the gas‐phase fragmentation of protonated p ‐toluenesulfonamides .…”

Gold‐Catalyzed Migrations and Ring Expansions

“…A 1,3-sulfonyl migration was reported in the synthesis of 3-pyrrolidinones and nitrones from N-sulfonyl hydroxylamines 106 (Scheme 46). First, attack of the nitrogen atom on the activated alkyne occurs to form a vinyl gold intermediate 107, which undergoes 1,3-migration of the sulfonyl group to provide product 108 92 . Related transformations have been recently reported for the synthesis of highly substituted 3-sulfonyl-1H-pyrroles 93 as well as indoles 94 .…”