Telomerization and dimerization of isoprene by in situ generated palladium–carbene catalysts
作者:Ralf Jackstell、Anne Grotevendt、Dirk Michalik、Larbi El Firdoussi、Matthias Beller
DOI:10.1016/j.jorganchem.2007.06.039
日期:2007.10
The palladium-catalyzed telomerization of isoprene with methanol and dimerization of isoprene have been studied in presence of in situ generated palladium–carbene catalysts. Unprecedented catalyst productivity has been observed for these two reactions. A selectivity switch from the telomer to the dimer product occurred by using different substituted carbene ligands. Among the imidazolium salts tested
在原位生成的钯-卡宾催化剂存在下,已经研究了钯催化的异戊二烯与甲醇的端粒化和异戊二烯的二聚化。对于这两个反应,已经观察到前所未有的催化剂生产率。通过使用不同的取代的卡宾配体,发生了从端粒到二聚体的选择性转换。在所测试的咪唑鎓盐中,甲磺酸1,3-二甲酰亚胺咪唑鎓盐(1),1,3-二甲磺酰1-4,5-二氢咪唑鎓氯化物(3)的端粒化反应收率最高,而1,3-双-(2,6-二异丙基苯基) )-4,5-二氢咪唑四氟硼酸盐(5)和1,3-双-(2,6-二异丙基苯基)-4,5-二甲基-4,5-二氢咪唑氯化物(9) 以高收率和良好的选择性形成二聚体。