The wavelength-regulated stereodivergent synthesis of (Z)- and (E)-1,4-enediones from phosphonium ylides

Abstract

The wavelength-regulated, methylene blue organic dye catalyzed stereodivergent synthesis of (Z)- and (E)-1,4-enediones from stabilized phosphorous ylides is reported. Broad ranges of substrates and functional groups are tolerated. Mechanistic studies suggested singlet-oxygen-promoted (E)-alkene formation via a possible phospha-1,2-dioxetane intermediate, followed by a blue-LED triggered (E) → (Z) isomerization reaction.