Metal free fluoroamination of allylsilanes: A route to 3-fluoropyrrolidines

The intramolecular fluoroamination of homoallylic amines activated by a triisopropylsilyl or p-tolyldiisopropylsilyl group was successfully performed in the presence of Selectfluor® in acetonitrile leading to anti or syn 3-fluoropyrrolidines. The stereochemical outcome of these fluorocyclizations is dictated by the geometry of the alkene precursor. In comparison with oxygen nucleophile, the use of N-tosyl or N-Boc nucleophiles benefits from superior control over stereoselectivity but suffers from competitive fluorodesilylation.