Enantioselective addition of organozinc reagents to ketones catalyzed by grafted isoborneolsulfonamide polymers and titanium isopropoxide
作者:Vicente J. Forrat、Diego J. Ramón、Miguel Yus
DOI:10.1016/j.tetasy.2009.01.011
日期:2009.1
The catalytic enantioselective addition of different organozinc reagents, such as diethylzinc, or in situ generated phenylzinc derivatives to simple aryl methyl ketones was accomplished using titanium tetraisopropoxide and a polymeric ligand grafted with trans-1-phenylsulfonylamino-2-isoborneolsulfonylamidocyclohexane, to give the corresponding tertiary alcohols with enantioselectivities of up to >99%
使用四异丙醇钛和接枝有反式-1-苯基磺酰基氨基-2-异冰片酚磺酰基酰胺基环己烷的聚合物配体,将不同的有机锌试剂(例如二乙基锌)或原位生成的苯基锌衍生物催化对映选择性加成到简单的芳基甲基酮上,得到相应的叔丁基对映选择性高达> 99%ee的醇。尽管在乙基化过程中获得了最高的对映选择性,但在苯基化过程中获得了最高的化学收率。配体可以重复使用至少3次,而活性没有任何重大损失。