Photoredox-Catalyzed Cross-Coupling of Enamides for the Assembly of β‑Difluoroimine Synthons
Published on 2017-10-12T13:34:02Z (GMT) by
A photoredox-catalyzed formal C<sub>sp3</sub>–C<sub>sp3</sub> cross-coupling reaction of enamides with bromodifluoro compounds is established. The resulting <i>gem</i>-difluoromethylenated γ-imines indicated high stability, excellent E<i>/Z</i> control, and broad functional group tolerance. These synthetic intermediates can efficiently transfer to difluoromethylenated γ-amino acids or δ-amino alcohols. Mechanistic analysis indicates that a radical/SET mechanism proceeding via a difluoroalkyl radical may be involved in the catalytic cycle.