Extended Data Fig. 5: Mechanistic experiments.

a, Synthesis of copper(II) complex C1 from L*7 and its X-ray structure. b, Complex C1 exhibited comparable catalytic activity with that in situ generated from CuI and L*7. c, EPR and HRMS experimental results indicated the formation of 190 from DMPO and the corresponding alkyl radical. d, In addition to the N-alkylation product 191, the radical clock substrate E46 also delivered 192-d₁, likely via radical cyclopropane ring opening and subsequent deuterium atom abstraction from THF-d₈. e, In the absence of amine nucleophiles, E1 was still completely consumed to afford the β-elimination product 1′ in high yield. f, By contrast, E40 bearing no β-hydrogen atoms gave rise to 193-d₁, likely via the formation of the corresponding alkyl radical and its subsequent deuterium atom abstraction from THF-d₈. g, A12 underwent highly chemoselective amine N-alkylation and sulfoximine C–N cross-coupling under the current and previously reported conditions, respectively, indicating strikingly different reaction mechanisms. DCM, dichloromethane. EPR, electron paramagnetic resonance. Calc., calculated. ESI, electrospray ionization. HRMS, high-resolution mass spectroscopy. DMPO, 5,5-dimethyl-1-pyrroline N-oxide. THF-d₈, tetrahydrofuran. Tol, p-toluenyl. HFacac, hexafluoroacetylacetonate.