A simple and efficient 1H NMR method for determining the absolute configuration of chiral α-hydroxy acid esters using a competing enantioselective conversion (CEC) strategy was developed. The α-hydroxy acid esters were acylated in the presence of Feng's chiral N,N′-dioxide–scandium(III) complex, and the faster reaction was identified when one enantiomer of the chiral α-hydroxy acid ester was treated
开发了一种简单有效的1 H NMR方法,使用竞争对映选择性转化(CEC)策略确定手性α-羟基酸酯的绝对构型。在Feng的手性N,N'-二氧化物-scan(III)配合物存在下使α-羟基酸酯酰化,当手性α-羟基酸酯的一种对映体用两种对映体进行处理时,可以识别出更快的反应。通过NMR分析反应混合物中的配体,无需进一步纯化。提供助记符以帮助分配基板的绝对配置。
Synthesis of a New Class of Chiral 1,5-Diphosphanylferrocene Ligands and Their Use in Enantioselective Hydrogenation
A new family of ferrocenylphosphane ligands has been prepared. Their flexible synthesis allows many structural modifications. The asymmetric induction of these ligands was examined in the hydrogenation of functionalized C=C, C=O, and C=N bonds. The enantioselectivity of the reaction was strongly dependent on the substituent R at the position alpha to the ferrocene moiety. In many cases, both enantiomeric
Ferrocenyl ligands and method for the production of such ligands
申请人:Knochel Paul
公开号:US20050240007A1
公开(公告)日:2005-10-27
The invention relates to ferrocenyl ligands of general formula (II), the S
fc
,S-enantiomer or the R
fc
,R-enantiomer of the ferrocenyl ligands of formula (II) being enriched, and a method for producing such ligands.