Stereospecific Synthesis of Highly Substituted Skipped Dienes through Multifunctional Palladium Catalysis
摘要:
graphicMultifunctional palladium catalysis is utilized in the one-pot stereocontrolled synthesis of tetrasubstituted alkenes. The homogeneous palladium dihalide catalyst utilized for bromo-/chloroallylation of alkynes is then reused in situ for a subsequent Suzuki cross-coupling reaction.
The synthesis of substituted styrenes was achieved by ring-closing enyne metathesis (RCEM)/elimination of enyne substrates 12. The synthetic approach was also effective for a different type of enyne substrate 14, yielding corresponding styrene 15.
The reaction of acetylenes and allylhalides using polymer-supported PdCl2 complex was carried out at room temperature for 48 hr. Codimerization products, 1,4-pentadiene derivatives, could be obtained in high yields. The catalytic behavior of the heterogeneous polymer Pd complex was compared with that of the homogeneous complex.