While being among the most common
functional handles present in
organic molecules, amines are a widely underutilized linchpin for
C–C bond formation. To facilitate C–N bond cleavage,
large activating groups are typically used but result in the generation
of stoichiometric amounts of organic waste. Herein, we report an atom-economical
activation of benzylic primary amines relying on the sulfur(VI) fluoride
exchange (SuFEx) click chemistry and the aza-Ramberg–Bäcklund
reaction. This two-step sequence allows the high-yielding generation
of 1,2-dialkyldiazenes from primary amines via loss of SO2. Excitation of the diazenes with blue light and an Ir photocatalyst
afford radical pairs upon expulsion of N2, which can be
coaxed into the formation of C(sp3)–C(sp2) bonds upon diffusion and capture by a Ni catalyst. This arylative
strategy relying on a traceless click approach was harnessed in a
variety of examples, and its mechanism was investigated.