Homopropargylic sulfonamides

Heterocycttzation. Formatu allylamine requires iodine and Sj 7V-acylcarbamates. A route to 4-of homopropargylic sulfonamides... 

Heterocyclization. Formation of A-tosyl-2-iodomethylaziridine from A-tosyl-allylamine requires iodine and NaH, whereas Ij-LiAl(OBu ) mediates cyclization of allyl A-acylcarbamates." A route to 4-iodo-2,3-dihydropyrroles by iodine-induced cyclization of homopropargylic sulfonamides involves a 5-endo-dig cyclization. ... 

When three molar equivalents of AgOAc were added to a previous protocol for the synthesis of a 4-iodo-2,3-dihydropyrrole derivative, the yield increased from 30% to 83%. In general, the addition of AgOAc gave reasonable yields (69-87%) for the synthesis of 4-iodo-2,3-dihydropyrroles from homopropargylic sulfonamides via a 5-endo-dig cyclization (eq 25). ... 

Intramolecular additions of alcohols or amines to olefins are recognized as useful methods to provide heterocyclic compounds. Kozmin and Zhang have achieved a gold-catalyzed synthesis of heterobicyclic alkenes by double cyclization of alcohols or sulfonamides which have a 1,5-enyne moiety [175]. As a typical example, unsaturated alcohol (95) is smoothly converted to 6-oxabicyclo[3.2.1]octane (96) in 90% yield using a 5 mol% of AuCls catalyst (Scheme 18.34). Cyclic ethers are also available from homopropargylic ethers with pendant alcohols through gold-catalyzed... 

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