Heck arylation of maleic anhydrides using arenediazonium tetrafluoroborates: Synthesis of mono- and diarylated maleic anhydrides and of the marine alkaloids prepolycitrin A and polycitrin A

The Heck arylation of maleic anhydrides using arenediazonium tetrafluoroborates was investigated. Symmetrical and unsymmetrical 3,4-diarylmaleic anhydrides, some of them showing interesting fluorescent properties, were prepared in one or two steps from cheap and commercially available maleic anhydride. This Heck arylation methodology constitutes a new and direct entry to the synthesis of arylated maleic anhydride materials, natural products and their derivatives, as demonstrated with the total syntheses of the marine alkaloids prepolycitrin A and polycitrin A and with the synthesis of a N-protected fluorescent phenylalanine.