Co-catalyzed sp3-sp3 coupling enabled by hydrofunctionalization of alkenes with nucleophiles

Complementary to classical transition-metal-catalyzed cross-coupling reactions, transition-metal-catalyzed hydrofunctionalization of alkenes has emerged as a powerful strategy for direct and rapid construction of sp³-sp³ linkages. Among various metals, cobalt has been widely used as a catalyst in the hydrofunctionalization of alkenes, demonstrating versatile catalytic reactivity for both electrophiles and nucleophiles to forge sp³-sp³ bonds. When employing nucleophiles as coupling partners, the hydrofunctionalization reactions usually requires the addition of oxidants, due to the presence of nucleophilic intermediate generated through cobalt-hydride-mediated hydrogen atom transfer (HAT) with alkenes. Cobalt-catalyzed hydrofunctionalizations of alkenes with nucleophiles represent an interesting and emerging strategy due to the use of both reductant and oxidant. This review summarizes the recent development of Co-catalyzed hydrofunctionalization of alkenes with nucleophiles, focusing on the construction of various C(sp³)-X(sp³) bonds (X = N, O, S, F). Future direction of this strategy to broaden the scope of sp³-sp³ bond formation is also discussed.