Mechanistic Investigation of the Ring Opening in the Staudinger Cycloaddition Involving Ketenes with Electron-Withdrawing Substituents
作者:Shanyan Mo、Jiaxi Xu
DOI:10.1002/hlca.201100483
日期:2012.7
The cycloaddition of ketenes and imines (Staudinger cycloaddition) is a general method for the synthesis of various β‐lactams. However, reactions of imines and ketenes with electron‐withdrawing substituents produce α,β‐unsaturated alkenamides, ring‐opening products of the intermediates generated from imines and the ketenes, even as sole products, besides the desired β‐lactams. The mechanism of the
Investigation of electrochemically induced Michael addition reactions. Oxidation of some dihydroxybenzene derivatives in the presence of azide ion
作者:Davood Nematollahi、Hosain Khoshsafar
DOI:10.1016/j.tet.2009.04.015
日期:2009.6
In aqueous solution containing azide ion as a nucleophile, electrochemicaloxidation of hydroquinone and some dihydroxybenzoic acids have been studied using cyclic voltammetry and controlled-potential coulometry. The voltammetric data show that electrochemically generated para and ortho-benzoquinones participate in Michael addition reactions with azide ions to form the corresponding diazido or diaminobenzoquinones