Boron Trifluoride Etherate Functioning as a Fluorine Source in an Iodosobenzene-Mediated Intramolecular Aminofluorination of Homoallylic Amines

A widely used Lewis acid BF3·Et2O was
shown to be capable of acting as an efficient fluorinating agent in
an intramolecular aminofluorination reaction of homoallylic amines
to provide 3-fluoropyrrolidines mediated by a commercially available
hypervalent iodine­(III) reagent PhIO at room temperature. A mechanism
involving a carbocation intermediate was proposed on the basis of
several experimental evidence.

广泛应用的路易斯酸（Lewis acid）三氟化硼乙醚络合物（BF3·Et2O）被证实可作为高效氟化试剂，可参与由商业可得的高价碘(III)试剂（hypervalent iodine(III) reagent）亚碘酰苯（PhIO）介导的室温下高烯丙基胺（homoallylic amines）分子内氨基氟化反应，从而制备得到3-氟吡咯烷（3-fluoropyrrolidines）。研究人员基于多项实验证据，提出了涉及碳正离子中间体（carbocation intermediate）的反应机理。