The Morita-Baylis-Hillman reaction for non-electron-deficient olefins enabled by photoredox catalysis.

A strategy for overcoming the limitation of the Morita-Baylis-Hillman (MBH) reaction, which is only applicable to electron-deficient olefins, has been achieved visible-light induced photoredox catalysis in this report. A series of non-electron-deficient olefins underwent the MBH reaction smoothly a novel photoredox-quinuclidine dual catalysis. The formed key β-quinuclidinium radical intermediates, derived from the addition of olefins with quinuclidinium radical cations, are used to enable the MBH reaction of non-electron-deficient olefins. On the basis of previous reports, a plausible mechanism is suggested. Mechanistic studies, such as radical probe experiments and density functional theory (DFT) calculations, were also conducted to support our proposed reaction pathways.