Copper-Mediated Hydrogen Atom Transfer Enabling General Catalytic Hydrofunctionalization of Olefins

The renaissance of catalytic hydrogen atom transfer from a metal hydride (MHAT) offers advanced tools for practicing sophisticated radical chemistry on simple olefins. While 3d transition metals like cobalt, iron, and manganese have been extensively studied in catalytic MHAT, the potential of copper remains unexplored. This is due to the polar reactivity exhibited by classical nucleophilic Cu(I) hydrides. Here we report the first examples of catalytic hydrofunctionalization reactions enabled by copper-mediated MHAT. The Cu-MHAT process produces alkyl radicals in high chemo- and regioselectivity, which are subsequently captured by Cu(II) species to undergo coupling reactions with an exceptionally broad scope of oxygen-, nitrogen-, halogen-, and carbon-based nucleophiles. The distinct reactivity and selectivity observed in Cu-MHAT system is attributed to the involvement of Cu(II)–H species, a hydrogen atom donor that possesses substantially altered charge distribution and weakened bonding in contrast to conventional Cu(I) hydrides. Preliminary results suggest potential extension to asymmetric catalysis and radical polymerization are viable. This work opens up new opportunities for MHAT chemistry by going beyond the common oxidation states.