Mechanism, kinetics and selectivity of selenocyclization of 5-alkenylhydantoins: an experimental and computational study.

ABSTRACT: The mechanism and selectivity of a bicyclic hydantoin formation by selenium-induced cyclization are investigated. The proposed mechanism involves the intermediates formed by an electrophilic addition of the selenium reagent on a double bond of the starting 5-alkenylhydantoin prior the cyclization. These intermediates are readily converted into the more stable cyclic seleniranium cations. A key step of the mechanism is an intramolecular cyclization which is realized through an anti-attack of the internal nucleophile, the amidic nitrogen, to the seleniranium cation yielding the intermediate imidazolinium cations. Their deprotonation is followed by the formation of the fused bicyclic reaction products. Important intermediates and key transition states are studied by using density functional t

SUBMITTER: Smit BM 

PROVIDER: S-EPMC4661018 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature