A reaction of 1,2-diketones and α-ketoimines with bis(iodozincio)methane gave cyclopropan-1,2-diol and 2-aminocyclopropanol respectively via nucleophilic [2+1]cycloaddition. The reaction proceeded via a sequential nucleophilic attack of the dizinc reagent to vicinal two carbonyl group. The reaction showed high diastereoselectivity to give cis-isomer via a face-to-face coordination between the substrate
We report an electrochemical protocol for the direct oxidation of internal alkynes in air to provide 1,2-diketones. A variety of functional groups and heterocycle-containing substrates can be tolerated well under mild conditions.
Tetrasubstituted carbon containing two different halogen substituents was constructed in a single-step operation by utilizing the carbene-like reactivity of dioxaphospholene through the tandem reaction of electrophilic and nucleophilic halogenating reagents. It was crucial to devise non-dealkylatable phosphoramidite, which enabled the efficient formation of geminal chlorofluorides from various 1,2-diketones
Synthesis of unsymmetrical benzils <i>via</i> palladium-catalysed α-arylation–oxidation of 2-hydroxyacetophenones with aryl bromides
作者:Takanori Matsuda、Souta Oyama
DOI:10.1039/d0ob00575d
日期:——
cross-coupling reaction between 2-hydroxyacetophenones and aryl bromides in the presence of a palladium catalyst. Experimental studies suggested a reaction mechanism involving a one-pot tandem palladium-catalysed α-arylation and oxidation, where aryl bromides play a dual role as mild oxidants as well as arylating agents.
The stereoselective thermal rearrangement of chiral lophine peroxides
作者:Masaru Kimura、Gonghao Lu、Hiroshi Iga、Mitsuru Tsunenaga、Zhiqiang Zhang、Zhizhi Hu
DOI:10.1016/j.tetlet.2007.01.146
日期:2007.4
The thermal reaction of chiral 2-phenyl-4-(p-X-phenyl)-5-(p-Y-phenyl)-4-tert-butyldimethylsilylperoxy-4H-isoimidazoles (5b: X = CF3, Y = OMe; 5c: X = CF3, Y = F) was carried out in DMSO. The chiral 2-phenyl-5-(p-X-phenyl)-5-(p-Y-phenyl)-5H-imidazol-4-ones (4b: X = CF3, Y = OMe; 4c: X = CF3, Y = F) were quantitatively obtained in 50–60% enantiomer excess (ee). The mechanism for the reaction was proved