Facile nucleophilic fluorination of primary alkyl halides using tetrabutylammonium fluoride in a tert-alcohol medium

Nonpolar protic reaction media such as t-amyl alcohol allow the aliphatic, nucleophilic fluorination reaction of primary haloalkane systems to fluoroalkanes, using tetrabutylammonium fluoride (TBAF), to proceed chemo-selectively at a reasonable reaction rate under mild conditions to afford the fluoro-product in high yield. As an example, the nucleophilic fluorination of 2-(3-iodopropoxy)naphthalene (1a) as the primary haloalkane model compound, with TBAF in acetonitrile as a polar aprotic solvent, CsF in t-amyl alcohol as a nonpolar protic solvent, and TBAF in t-amyl alcohol for 1 h provided 2-(3-fluoropropoxy)naphthalene (2a) in 38, 5, and 76% yields, respectively.