Copper on iron promoted one-pot synthesis of β-aminoenones and 3,5-disubstituted pyrazoles
摘要:
The reaction of hydroximoyl chlorides with acetylenes in the presence of a copper on iron bimetallic system leads to beta-aminoenones via reductive ring opening of isoxazole intermediates. The valuable beta-aminoenone building blocks can be isolated or transformed into pyrazoles with the addition of hydrazine in a straightforward one-pot procedure. (C) 2013 Elsevier Ltd. All rights reserved.
Radical Enamination of Vinyl Azides: Direct Synthesis of N-Unprotected Enamines
摘要:
An electron-withdrawing-group-generable radical-induced enamination of vinyl azides is reported, which results in a variety of beta-functionalized N-unprotected enamines in a stereoselective manner. A plausible mechanism involving an unusual 1,3-H transfer of in situ generated iminyl radical intermediate was proposed on the basis of experimental results and DFT calculations.
Asymmetric Aza-Diels–Alder Reactions of in Situ Generated β,β-Disubstituted α,β-Unsaturated N–H Ketimines Catalyzed by Chiral Phosphoric Acids
作者:Shunlong He、Huanchao Gu、Yu-Peng He、Xiaoyu Yang
DOI:10.1021/acs.orglett.0c01994
日期:2020.7.17
A novel asymmetricsynthesis of dihydropyridinones with vicinal quaternary stereocenters has been realized by asymmetric aza-Diels–Alder reactions of 3-amido allylic alcohols with oxazolones enabled by chiral phosphoric acid catalysis. A series of aryl/alkyl- and alkyl/alkyl-disubstituted 3-amido allylic tertiary alcohols and 4-substituted oxazolones could be well tolerated in these reactions, producing