Formal Aza‐Wacker Cyclization by Tandem Electrochemical Oxidation and Copper Catalysis
作者:Xiangli Yi、Xile Hu
DOI:10.1002/anie.201814509
日期:2019.3.26
In oxidative electrochemical organic synthesis, radical intermediates are often oxidized to cations on the way to final product formation. Herein, we describe an approach to transform electrochemically generated organic radical intermediates into neutral products by reaction with a metalcatalyst. This approach combines electrochemical oxidation with Cu catalysis to effect formal aza‐Wacker cyclization
N-aryl-4-vinyloxazolidin-2-ones. The success of the reaction depends on the acidity of the aniline and requires in situ conversion of the dicarbonate into carbamate carbonate by nucleophilicattack of the aniline conjugate base followed by palladium-catalyzed intramolecular cyclization.
Palladium(0)-Catalyzed Asymmetric Cycloaddition of Vinyloxiranes with Heterocumulenes Using Chiral Phosphine Ligands: An Effective Route to Highly Enantioselective Vinyloxazolidine Derivatives
作者:Chitchamai Larksarp、Howard Alper
DOI:10.1021/ja964335l
日期:1997.4.1
Cycloaddition reaction of 2-vinyloxiranes with carbodiimides using Pd2(dba)3·CHCl3, and TolBINAP as the chiral ligand, in THF at ambient temperature, afforded 4-vinyl-1,3-oxazolidin-2-imines in 70−99% yield and in up to 95% ee. The stereoselectivity is strongly influenced by the structure of the chiral phosphine ligands and substrates, as well as by the reaction conditions. The enantiodetermination