Asymmetric IrI-Catalysed Allylic Alkylation Of Monosubstituted Allylic Acetates With Phosphorus Amidites As Ligands
作者:Björn Bartels、Cristina García-Yebra、Günter Helmchen
DOI:10.1002/ejoc.200390162
日期:2003.3
2′-binaphthol and a variety of chiral amines were employed as ligands in IrI-catalysed allylic alkylations of unsymmetrically substituted allylic acetates. The enantio- and regioselectivities of these reactions were investigated. Phosphorus amidites of bulky secondary chiral amines induced enantioselectivities of up to 94% ee in reactions of linear substrates. Phosphorus amidites derived from chiral
衍生自 2,2'-联萘酚和各种手性胺的单齿磷酰胺被用作 IrI 催化的不对称取代的烯丙基乙酸酯的烯丙基烷基化反应中的配体。研究了这些反应的对映选择性和区域选择性。庞大的手性仲胺的磷酰胺在线性底物的反应中诱导了高达 94% ee 的对映选择性。由手性伯胺衍生的磷酰胺,以前没有用于不对称催化,提供了改进的区域选择性。使用 LiCl 作为添加剂可以提高区域选择性和对映选择性。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)