Pd-Catalyzed Decarboxylative Asymmetric Protonation (DAP) Using Chiral PHOX Ligands vs. Chiral Ligand-Free Conditions Employing (1<i>R</i>
,2<i>S</i>
)(-)-Ephedrine - A Comparison Study
作者:Jinju James、Ramulu Akula、Patrick J. Guiry
DOI:10.1002/ejoc.201900267
日期:2019.4.9
We report a decarboxylative asymmetric protonation (DAP) protocol for α‐aryl ketones that utilizes (1R,2S)‐(–)ephedrine, a cheap and readily available chiral proton donor. The results are compared with the DAP using either Meldrum's acid or formic acid in the presence of chiral P,N‐ligands, for a focused library of substrates. In addition, a stereochemical rationale is proposed to explain the preferred
我们报告了α-芳基酮的脱羧不对称质子化(DAP)协议,该协议利用了(1 R,2 S)-(-)麻黄碱,一种廉价且容易获得的手性质子供体。在手性P,N配体存在的情况下,将结果与使用Meldrum酸或甲酸的DAP进行比较,以形成聚焦的底物库。另外,提出了立体化学原理来解释观察到的不对称诱导的优选含义。