Mild and Selective Palladium-Catalyzed Dimerization of Terminal Alkynes To Form Symmetrical (<i>Z</i>,<i>Z</i>)-1,4-Dihalo-1,3-dienes
作者:Jin-Heng Li、Yun Liang、Ye-Xiang Xie
DOI:10.1021/jo0486645
日期:2004.11.1
A regioselective and stereoselective palladium-catalyzeddimerization of terminal alkynes method for the synthesis of symmetrical (Z,Z)-1,4-dihalo-1,3-dienes is presented. In the presence of a catalytic amount of PdX2 and 3 equiv of CuX2 (X = Cl and Br), terminal alkynes were dimerized to afford (Z,Z)-1,4-dihalo-1,3-dienes in good yields. The results showed that the effect of solvent had a fundamental
dimerization of terminalalkynes with trichloroacetyl chloride as chlorine donor proceeds in the presence of rhodium catalysts to give (Z,Z)-1,4-dichloro-1,3-butadienes stereoselectively. Ligand screening has revealed that reactions using sterically bulky and electron-donating ligands like trimesitylphosphine are high yielding. The reaction is compatible with a range of functional groups to give the title