Ethynylation of aryl halides by a modified Suzuki reaction: Application to the syntheses of combretastatin A-4, A-5 and lunularic acid

Article abstract of DOI:10.1002/jlac.199619961224

On treatment with trimethyl borate sodium acetylide undergoes a palladium-catalyzed cross coupling with functionalized aryl halides or triflates in reasonable to good yields. The ethynylarenes thus obtained serve as building blocks for the formation of the highly effective tubulin polymerization inhibitors combretastatin A-4 (1) and A-5 (2) as well as for the synthesis of the plant-growth regulator lunularic acid (36). VCH Verlagsgesellschaft mbH, 1996.