An Isothiourea-Catalyzed Asymmetric [2,3]-Rearrangement of Allylic Ammonium Ylides
摘要:
Benzotetramisole promotes the catalytic asymmetric [2,,3]-rearrangement of allylic quaternary ammonium salts (either isolated or prepared in situ from p-nitrophenyl bromoacetate and the corresponding allylic amine), generating syn-alpha-amino acid derivatives with excellent diastereo- and enantioselectivity (up to >95:5 dr; up to >99% ee).
Chiral α-Amino Acid/Palladium-Catalyzed Asymmetric Allylation of α-Branched β-Ketoesters with Allylic Amines: Highly Enantioselective Construction of All-Carbon Quaternary Stereocenters
作者:Ya-Nan Xu、Meng-Zeng Zhu、Shi-Kai Tian
DOI:10.1021/acs.joc.9b02282
日期:2019.11.15
use of allylic amines as allylating agents in the chiral α-aminoacid/palladium-catalyzed asymmetric allylation of α-branched β-ketoesters, providing highly enantioselective access to all-carbon quaternary stereocenters. Notably, the formation of a primary amine, a secondary amine, or ammonia as a byproduct has little influence on the enantioselectivity for the catalytic asymmetric synthesis of structurally