Enantioselective Desymmetrization via Carbonyl-Directed Catalytic Asymmetric Hydroboration and Suzuki–Miyaura Cross-Coupling
摘要:
The rhodium-catalyzed enantioselective desymmetrization of symmetric gamma,delta-unsaturated amides via carbonyl-directed catalytic asymmetric hydroboration (directed CAHB) affords chiral secondary organoboronates with up to 98% ee. The chiral gamma-borylated products undergo palladium-catalyzed Suzuki-Miyaura cross-coupling via the trifluoroborate salt with stereoretention.
Desymmetrization of Prochiral Cyclopentenes Enabled by Enantioselective Palladium-Catalyzed Oxidative Heck Reaction
作者:Guihua Chen、Jian Cao、Qian Wang、Jieping Zhu
DOI:10.1021/acs.orglett.9b04357
日期:2020.1.3
catalytic amount of Pd(TFA)2 and a chiral Pyox ligand under oxygen atmosphere, oxidative Heck reaction between arylboronic acids and 4-substituted or 4,4-disubstituted cyclopent-1-enes afforded the chiral arylated products with concurrent creation of two stereocenters in good yields with excellent diastereo- and enantioselectivities.
nucleopalladation of alkynes have been developed into powerful synthetic tools for the synthesis of functionalized heterocycles. However, a catalytic enantioselective version of this class of reactions remains scarce. We report herein that reaction of 2‐alkynylanilines with prochiral cyclopentenes in the presence of a catalytic amount of Pd(OAc)2, a chiral bidentate pyrox ligand and O2 as terminal oxidant affords the