Here, we report a dual copper/transient directing group catalyzed C(sp 2 )-H functionalization of benzylamines with sulfinate salts, using manganese (IV) oxide as the terminal oxidant. This represents the first C-S bond forming transient C-H functionalization methodology for amines, and the first example of sub-stoichiometric copper salt being used with a transient directing group. Computational studies by DFT provide insights into the mechanism of the reaction. We first examined different aldehyde additives to function as the transient directing group, employing a catalytic amount (25 mol% TDG) along with a stoichiometric quantity of copper fluoride (ie 2 equiv, as required by the expected oxidative mechanism). HFIP was used as solvent at 100 ºC in the presence of K2CO3, with 1 equiv of toluene sodium sulfinate. No reaction was observed in the absence of a TDG nor using glyoxalic acid TDG1 or 2-phenoxyacetaldehyde dimethyl acetal TDG2. Pleasingly, salicaldehyde (TDG3) was effective under these conditions, affording 44% yield of sulfone 3aa. 5-Substituted salicaldehydes (TDG4-6) gave very similar improved yields (54-56%), whereas 6-substituted derivatives were less effective (TDG7-8). 2-Hydroxynicotinaldehyde (TDG9) was identified as an effective TDG, affording the sulfonylated product in 60% yield, and was selected for further optimization.