Synthesis of stereodefined polysubstituted olefins. 1. Sequential intermolecular reactions involving selective, stepwise insertion of Pd(0) into allylic and vinylic halide bonds. The stereoselective synthesis of disubstituted olefins

Palladium-catalyzed allylic substitution and cross-coupling reactions have been combined into a sequential procedure to provide a range of disubstitut ed olefin products starting from two-, three-, and four-carbon common olefi n templates. Diverse application of this template strategy is demonstrated in a variety of model studies and in a parallel synthesis (combinatorial) a pproach to prepare an allylic amine molecular library. An approach toward t he preparation of astaxanthin beta -D-diglucoside, an interesting antioxida nt whose total synthesis has yet to be reported, using the olefin-template approach is also discussed.