An improved iron-mediated synthesis of N-2-aryl substituted 1,2,3-triazoles
作者:Ahmed Kamal、Ponnampalli Swapna
DOI:10.1039/c3ra22485f
日期:——
Treatment of various chalcones and sodium azide in the presence of catalytic amounts of commercially available iron oxide nanoparticles, followed by the addition of aryl halides afforded N-2-arylated 1,2,3-triazoles in very good yields. This tandem three-component reaction involves an oxidative 1,3-dipolar cycloaddition of the chalcone and azide and subsequent regioselective N-2-arylation. The nano-catalyst is easily recoverable and can be reused without any significant loss in catalytic activity.
Diastereo- and Enantioselective Organocatalytic Direct Conjugate Addition of γ-Butenolide to Chalcones
作者:Yinan Zhang、Chenguang Yu、Yafei Ji、Wei Wang
DOI:10.1002/asia.201000014
日期:——
A diastereo‐ and enantioselectiveconjugateaddition reaction of γ‐butenolide with chalcones has been developed. Notably, unmodified γ‐butenolide was directly employed as a nucleophile in the Michael addition reactions. This process was catalyzed by a previously reported cyclohexane diamine thiourea under mild reaction conditions to afford enantioenriched synthetically and biologically important substituted
An enantioselective magnesium-catalyzed conjugate addition of trimethylsilyl cyanide to chalcones in the presence of Py-BINMOL with multiple stereogenic centers, through dual activation of substrates, has been successfully developed with moderate to good enantioselectivities and in good yields.
It was found that 1,2-trifluoromethylation reactions of ketones, enones, and aldehydes were easily accomplished using the Prakash reagent in the presence of catalytic amounts of cesium carbonate, which represents an experimentally convenient, atom-economic process for this anionic trifluoromethylation of non-enolisable aldehydes and ketones.