Dual Copper- and Aldehyde-Catalyzed Transient C–H Sulfonylation of Benzylamines

This study reports the first example of using a dual catalytic system with copper(II) acetate and 2-hydroxynicotinaldehyde to achieve transient C(sp2)–H sulfonylation of benzylamines with sulfinate salts via a dynamically formed imine directing group. Manganese(IV) oxide was identified as an effective oxidant and base. Computational density functional theory investigations suggest that the transient directing group lowers the energy barrier for an acetate-mediated, turnover-limiting C–H activation step and subsequent combination of the cupracycle with a RSO2 radical.