Two pathways for the stereomutation of 2-substituted 1-(tert-butylsulfinyl)naphthalenes

Abstract

The synthesis of a number of 2-substituted 1-(tert-butylsulfinyl)naphthalenes is described and the free energies of activation (ΔG ^‡ = 50.0–80.7 kJ mol^–1) for their stereomutation about the S–Ar bonds have been determined. It is shown that two pathways operate for this process. For the smaller 2-substituents (F, OMe, CO₂Prⁱ), the tert-butyl group passes over the 2-position, and for larger substituents (Cl, Me, Br) it passes over the 8-position of the naphthalene ring.