Highly Regio- and Enantioselective Synthesis of N-Substituted 2-Pyridones: Iridium-Catalyzed Intermolecular Asymmetric Allylic Amination
作者:Xiao Zhang、Ze-Peng Yang、Lin Huang、Shu-Li You
DOI:10.1002/anie.201409976
日期:2015.2.2
The first iridium‐catalyzed intermolecularasymmetric allylic amination reaction with 2‐hydroxypyridines has been developed, thus providing a highly efficientsynthesis of enantioenriched N‐substituted 2‐pyridone derivatives from readily available starting materials. This protocol features a good tolerance of functional groups in both the allylic carbonates and 2‐hydroxypyridines, thereby delivering
A specific N-alkylation of 2-hydroxypyridines is achieved by reacting with organohalides under catalyst- and base-free conditions. The observed HX-facilitated conversion of pyridyl ether intermediates to 2-pyridone products may account for the success and specific N-alkylation of the reaction under the unexpectedly simple conditions. This new reaction may provide a useful alternative for the synthesis of 2-pyridones and analogous structures because of its >99% N-selectivity, relatively broad scopes of both substrates, and no mandatory use of catalysts and bases.
Insights into Substrate Self-Assisted Activation of Allylic Alcohols Guiding to Mild Allylic Substitution of Tautomerizable Heteroarenes
作者:Qiuju Zhou、Lingyun Zheng、Bing Ma、Lijun Huang、Aoqi Liu、Xinhua Cao、Jing Yu、Xiantao Ma
DOI:10.1021/acs.joc.0c00094
日期:2020.4.3
A substrate self-assisted activation of allylic alcohols by tautomerizable heteroarenes via hydrogen bonding was disclosed by various NMR techniques, including variable-temperature(1)H NMR, Job plot, and H-1 NMR titration. Guided by these finding, a much milder allylic substitution of tautomerizable heteroarenes with allylic alcohols was developed, affording the target products in high yields.