Sequential Catalytic Isomerization and Allylic Substitution. Conversion of Racemic Branched Allylic Carbonates to Enantioenriched Allylic Substitution Products
作者:Shashank Shekhar、Brian Trantow、Andreas Leitner、John F. Hartwig
DOI:10.1021/ja0644273
日期:2006.9.1
A catalytic protocol for the conversion of readily accessible racemic, branched aromatic allylic esters to branched allylic amines, ethers, and alkyls has been developed. Palladium-catalyzed isomerization of branched allylic esters to terminal allylic esters, followed by sequential iridium-catalyzed allylic substitution, gave the branched allylic products in good yield with high regioisomeric and enantiomeric
已经开发了一种用于将容易获得的外消旋、支链芳族烯丙酯转化为支链烯丙胺、醚和烷基的催化方案。钯催化的支链烯丙基酯异构化为末端烯丙基酯,然后依次进行铱催化的烯丙基取代,以良好的收率得到支链烯丙基产物,具有高区域异构和对映异构选择性。富电子和缺电子支化烯丙基酯均产生 >90% ee 的产物。对于来自乙酸2-噻吩酯和碳酸二烯酯的反应的产物,也观察到高对映体过量。
Highly Regio- and Enantioselective Palladium-Catalyzed Allylic Alkylation and Amination of Dienyl Esters with 1,1‘-<i>P,N</i>-Ferrocene Ligands
作者:Wen-Hua Zheng、Na Sun、Xue-Long Hou
DOI:10.1021/ol051882f
日期:2005.11.1
[reaction, structure: see text] Pd-catalyzed asymmetric allylicalkylation of dienyl acetates 1 and amination of allyl acetates 2 provides the corresponding chiral products in high regio- and enantioselectivities using 1,1'-P,N-ferrocenes L1a and L2d as ligands, respectively.