Electrochemical phosphorylation of α,β-unsaturated carboxylic acids via decarboxylative cross-coupling reaction†

DABCO-mediated electrochemical decarboxylative coupling reaction of Ph₂P(O)H with alkenyl acids has been developed. A range of (E)-alkenylphosphine oxides were obtained with broad substrate scope and excellent regioselectivity under metal-free and ambient conditions. Mechanistic studies suggested that the phosphinyl radical was generated through a hydrogen atom transfer (HAT) process mediated by DABCO⁺˙. Moreover, Cp₂Fe-mediated electrochemical synthesis of alkynylphosphine oxides has been established.