The control of stereochemistry by the pentafluorosulfanyl group

The influence of pentafluorosulfanylation on biological activity has been revealed in numerous comparative studies of biologically active compounds, but considerably less is known about the influence of pentafluorosulfanylation on reactivity. Among the distinctive properties of the pentafluorosulfanyl group is the profound dipole moment that results from introduction of this substituent. It has been shown that dipolar effects coupled with the steric demand of the SF5 group may be employed to influence the stereochemistry of reactions, especially those processes with significant charge separation in the transition state. The Staudinger ketene-imine cycloaddition reaction is an ideal platform for investigation of dipolar control of diastereoselectivity by the pentafluorosulfanyl group.