In
the presence of a thiyl radical species, the catalytic
Markovnikov
thiol–ene reaction is challenging because it prefers to proceed
via a radical pathway, thereby leading to anti-Markovnikov
selectivity. In this work, a rare example of thiyl radical engaged
in Markovnikov thiol–ene reaction enabled by cobalt catalysis
is reported. This protocol features the avoidance of unique oxidants,
exclusive regioselectivity, and broad substrate scope. Scalable synthesis
and late-stage modification of complex molecules demonstrate the practicability
of the protocol.