An Efficient Approach for Monofluorination via Highly Regioselective Fluorohydroxylation Reaction of 3-Aryl-1,2-allenes with Selectfluor

The internal CC double bond in 3-aryl-1,2-allenes was highly regioselectively fluorohydroxylated to afford 2-fluoroalken-3-ols in 37−88% yields by using Selectfluor as the electrophilic reagent. The regioselectivity may be determined by the electronic effect, while the reactivity may be controlled by the stabilization effect of the aryl group in the allylic cationic intermediates.