Facile Synthesis of Chiral Diphosphine-Containing Multiple Dendrimeric Catalysts for Enantioselective Hydrogenation
作者:Liwen Zhao、Ji Liu、Yu Feng、Yanmei He、Qinghua Fan
DOI:10.1002/cjoc.201200648
日期:2012.9
PyrPhos‐functionalized codendrimers have been synthesized via a liquid‐phase strategy in high yields. The resulting dendrimeric PyrPhos ligands were purified by a simple solvent precipitation without the need for chromatographic separation, and well characterized by 1H, 13C and 31P NMR, MALDI‐TOF mass spectroscopy as well as elemental analysis. Their rhodium complexes were applied to the asymmetric hydrogenation of
通过液相策略以高收率合成了一种新型的手性二膦PyrPhos功能化共聚酯。生成的树枝状PyrPhos配体通过简单的溶剂沉淀法纯化,无需进行色谱分离,并通过1 H,13 C和31 P NMR,MALDI-TOF质谱以及元素分析进行了很好的表征。他们的铑配合物用于α的不对称氢化乙酰胺基肉桂酸。获得了优异的对映选择性,这与使用相应的小分子催化剂的对映选择性相当。另外,这些共聚体催化剂表现出比具有位于聚(芳基醚)树突的焦点处或聚(丙烯亚胺)树状体的外围的Rh(PyrPhos)位点的树状聚合物催化剂更好的催化性能。