A biomimetic S H 2 cross-coupling mechanism for quaternary sp 3 -carbon formation

Radical substitution Nucleophilic substitution is a venerable reaction in organic chemistry. Typically, an incoming ion delivers two electrons to a carbon center while a departing ion takes two electrons away with it. The one-electron analog, homolytic substitution, is more rarely used, in part because the incoming neutral radicals can self-couple instead of bonding to the intended target. Liu et al . report that an iron porphyrin catalyst can direct homolytic substitution between primary and tertiary carbon radicals by selectively activating the primary partners. —JSY