Metal-free intramolecular aminofluorination of alkenes mediated by PhI(OPiv)2/hydrogen fluoride–pyridine system

A convenient, metal-free intramolecular aminofluorination of alkenes has been developed. Employing readily available PhI(OPiv)2 and hydrogen fluoride–pyridine in the presence of BF3·OEt2, tosyl-protected pent-4-en-1-amines were converted to 3-F-piperidines in one step in good yields as well as high stereoselectivity.