Control reactions established that the copper(II) acetate was critical to the coupling, and about 1 turnover was achieved in the absence of oxidant (Entries 2,3). In the absence of TDG9 a low, but non-zero yield was obtained (Entry 4). Testing other TDG under the catalytic conditions showed the same trend as using stoichiometric copper (Entries 5-7). Changing the oxidant from MnO2 to K2S2O8 was detrimental for the reaction (Entry 8). The addition of K2CO3 gave no change in the isolated yield (Entry 10). The addition of TEMPO as radical trap fully suppressed the reaction, suggesting a radical reaction pathway is in operation (Entry 9). Notably, the formation of sulfonamide was never observed despite the potential for direct coupling with the amine moiety. The reaction scope varying the sulfinate salt was then investigated (Scheme 2). Sulfonyl amine 3aa was obtained in 68% yield, which could be scaled to gram scale (10 mmol), affording the product in 61% (1.76 g). Aryl sulfinates bearing electron neutral (H), electron rich (OMe, tBu), or electron poor substituents (CF3, halogens) all gave good yields with a slight preference for the electron poor sulfinate salts (3ab-3ah). A lower yield was observed for the more sterically hindered naphthyl substituted example 3ai. Methyl and cyclopropyl sulfinate salts were both highly effective, affording the sulfones 3aj and 3ak in 88% and 70% respectively. The reaction with BCP sulfinate salt was also successful in generating sulfone 3al, the BCP motif being of interest as a phenyl isostere. We next explored the tolerance of the reaction to changes in the benzylamine component (Scheme 3). Initially, we varied the substituent in the 3-position (para to the C-H bond being functionalized) and found substrates with electron rich and electron poor substituents reacted effectively (3ba-3ea), with slightly improved yields for the 3-OMe (3ba) and 3-F-phenyl (3ca) derivatives. Changing the bromo substituent from the 3-to 4-position gave sulfonyl amine 3fa in 71%. The pentafluorosulfanyl (SF5) group is increasingly of interest in medicinal chemistry, and a SF5 substituted benzylamine was sulfonylated effectively to give amine 3ga in 58% yield. The functionalization of more challenging pyridyl containing substrate 3ha was also realized despite the presence of the additional coordinating moiety. 2-Napthyl derivative 3ia was formed with selective reaction at the 3-position. A range of a-alkylbenzylamines were also converted to the sulfonylated products 3ja, 3ka and 3la in good yields. Sulfonylation of enantioenriched amine retained the chirality of the starting amine (>99% ee). However, unsubstituted benzylamines were unsuccessful. Ethyl and benzyl substituted amines were sulfonylated exclusively at the ortho-position to give sulfones 3ma and 3na both in 60% yield. In the benzyl substituted example, no sulfonylation of the more distal aryl group was observed. Biaryl substrates 3on and 3po possessing functional groups capable of directing ortho-metalation were sulfonylated exclusively at the ortho position to the amine without any sulfonylation adjacent to either the ester or ether functionality. Furthermore, both the methyl ester and benzyl groups remained intact under these conditions. The amine products generated in this transient process were directly available for further derivatization (Scheme 4). To illustrate this, sulfone 3aa was readily acetylated with acetyl chloride to form amide 4, and was converted to aminooxetane 5 using an oxetane sulfonyl fluoride reagent in a defluorosulfonylative process. Reductive alkylation and nucleophilic aromatic substitution (SNAr) reactions as commonly employed in medicinal chemistry programs were also readily demonstrated to provide alkyl amine 6 and aryl amine 7.