Direct C(sp²)-H activation of allenes via hydrogen-atom transfer (HAT) in organic synthesis

With the flourishing progress of radical chemistry, many hydrogen-atom transfer (HAT) reactions have been developed to investigate the functionalization of various C-H bonds, such as alpha-ether, allylic, and benzylic C-H bonds. However, the direct C(sp(2))-H activation of allenes, especially in a hydrogen atom abstraction fashion, still remains a formidable challenge. Recent studies have demonstrated the unique ability of the direct HAT strategy to unlock new reactivity of allenes. It is believed that more valuable transformations of this strategy will be developed in the future.