Pd-Catalyzed Reaction of Sterically Hindered Hydrazones with Aryl Halides: Synthesis of Tetra-Substituted Olefins Related to <i>iso</i>-Combretastatin A4
PdCl2(MeCN)2 in combination with dppp proved to be a powerful and efficient catalyst for the coupling of stericallyhindered N-arylsulfonylhydrazones with aryl halides, thus providing a flexible and convergent access to tetrasubstituted olefins related to iso-combretastatin A4 in good yields. This new protocol has been applied successfully to the formal synthesis of biphenylisopropylidene 4-pyridine
Synthesis, biological evaluation, and structure–activity relationships of tri- and tetrasubstituted olefins related to isocombretastatin A-4 as new tubulin inhibitors
inhibitory activity as well as for cytotoxic activity. The most potent compounds are 1,1-diaryl-2-methoxyethylenes 4b, 4d and 4e having a trisubstituted double bond. They exhibited good antiproliferativeactivity against various humancancercelllines (GI50 = 8–80 nM). Compounds 4b and 4e strongly inhibited tubulin polymerization with IC50 values of 2 and 3 μM, respectively, and induced cell cycle arrest