Efficient Reduction of Electron-Deficient Alkenes Enabled by a Photoinduced Hydrogen Atom Transfer

Direct hydrogen atom transfer from a photoredox-generated Hantzsch ester radical cation to electron-deficient alkenes has enabled the
development of an efficient formal hydrogenation under mild, operationally simple conditions. The HAT-driven mechanism, key to circumvent
the problems associated with the low electron affinity of alkenes, is supported by experimental and computational studies. The reaction is applied
to a variety of cinnamate derivatives and related structures, irrespective of the presence of electron-donating or electron-withdrawing
substituents in the aromatic ring and with good functional group compatibility.