title: Mild and selective palladium-catalyzed dimerization of terminal alkynes to form symmetrical (Z,Z)-1,4-dihalo-1,3-dienes.
abstract: A regioselective and stereoselective palladium-catalyzed dimerization 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 PdX(2) and 3 equiv of CuX(2) (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 influence on the chemoselectivity of the dimerization reaction. The mechanism of the palladium-catalyzed dimerization reaction is also discussed.
authors.affiliation: Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, China. jhli@hunnu.edu.cn
authors.forename: Jin-Heng
authors.initials: JH
authors.lastname: Li
authors.forename: Yun
authors.initials: Y
authors.lastname: Liang
authors.forename: Ye-Xiang
authors.initials: YX
authors.lastname: Xie