955-83-9Relevant articles and documents
Hexafluoroisopropanol as solvent and promotor in the Paal-Knorr synthesis of N-substituted diaryl pyrroles
Schirmacher, Robert H.E.,R?sch, Daniel,Thomas, Franziska
, (2021/02/20)
An additive-free synthesis of challenging N-substituted aryl pyrroles from the often poorly soluble corresponding 1,4-diketones by means of the Paal-Knorr pyrrole synthesis is reported, which makes use of the unique properties of 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) as a solvent and reaction promotor. Our procedure offers simple execution and purification as well as easy scale-up and can be applied in the Paal-Knorr synthesis of a large number of structurally diverse pyrroles including the synthetically challenging tetra- and penta-substituted pyrroles in moderate to excellent yields. HFIP can also be used as solvent in the Paal-Knorr synthesis of furans and thiophenes; however, the solvent effect is more pronounced in synthesis of pyrroles.
Method for preparing furan compound from brominated arone
-
Page/Page column 5, (2021/06/13)
The invention provides a method for synthesizing a furan compound by taking brominated arone and methyl ketone or cyclic ketone as raw materials and directly reacting under the action of tetraisopropyl titanate. The method comprises the following steps: under the protection of inert gas, stirring and heating a reaction mixture of methyl ketone or cyclic ketone and bromo-arone, and then adding tetraisopropyl titanate for reaction; and after the reaction is finished, separating and purifying the obtained reaction mixture to obtain the polysubstituted furan compound. The synthesis method provided by the invention has the advantages of easily available raw materials, low cost, simple operation and easy control, no solvent, good substrate universality and functional group compatibility, and is suitable for industrial mass production.
Synthesis of 1,4-Dicarbonyl Compounds by Visible-Light-Mediated Cross-Coupling Reactions of α-Chlorocarbonyls and Enol Acetates
Liu, Qiang,Wang, Rui-Guo,Song, Hong-Jian,Liu, Yu-Xiu,Wang, Qing-Min
supporting information, p. 4391 - 4396 (2020/09/21)
Herein, we report a protocol for visible-light-mediated radical coupling reactions of α-chloroketones and enol acetates to afford 1,4-dicarbonyl compounds, which are important precursors and intermediates in organic synthesis. The reaction involves photoredox-catalyzed activation of the α-chloroketone upon photoelectron transfer, carbon–chlorine bond cleavage, and coupling of the resulting radical with the carbon–carbon double bond of the enol acetate. This mild protocol has a wide substrate scope and moderate to good yields. (Figure presented.).
