Synthesis of Unsymmetrical 1,4-Dicarbonyl Compounds by Photocatalytic Oxidative Radical Additions
作者:Ya Dong、Ruining Li、Junliang Zhou、Zhankui Sun
DOI:10.1021/acs.orglett.1c02208
日期:2021.8.20
Herein we report a photocatalytic oxidative radical addition reaction for the synthesis of unsymmetrical 1,4-dicarbonyl compounds. This reaction utilizes a desulfurization process to generate electrophilic radicals, which add to α-halogenated alkenes and undergo further oxidation to deliver 1,4-dicarbonyl compounds. This mild and highly efficient method provides a valuable alternative to known strategies
Novel Synthesis of Fluoroalkylated α,β-Unsaturated Ketones by the Oxygenative Perfluoroalkylation of α-Chlorostyrenes
作者:Masato Yoshida、Masanori Ohkoshi、Masahiko Iyoda
DOI:10.1246/cl.2000.804
日期:2000.7
The photochemical reaction of perfluoroalkyl iodide with α-chlorostyrenes in the presence of hexabutylditin under oxygen atmosphere produced fluoroalkylated α,β-unsaturated ketones in moderate to good yields.
Here we describe a ruthenium-catalyzed regioselective hydrohalogenation reaction of alkynes under mild conditions. Commercially simple halogen sources such as KI, ZnBr2, and ZnCl2 were employed to achieve this transformation. Alkynes derived from bioactive molecules such as l-(−)-borneol, l-menthol, and estrone were also suitable for the transformation, demonstrating the potential synthetic value of
This process is a process for production of a vinyl chloride polymer by suspension polymerization or emulsion polymerization of vinyl chloride monomer or a mixture of vinyl chloride monomer with a vinyl monomer copolymerizable with said vinyl chloride monomer in an aqueous medium, characterized in that the polymerization is carried out in a polymerizer, the inner wall surface and portions of the auxiliary equipment thereof which may come into contact with the monomer during polymerization being previously coated with a scaling preventive comprising at least one selected from dyes, pigments and aromatic or heterocyclic compounds having at least 5 conjugated π bonds, while controlling the chloride ion concentration in the reaction mixture to not higher than 100 ppm. According to said process, scaling onto the inner wall surface of a polymerizer, etc. during polymerization can be prevented effectively and surely.
Lewis acid catalyzed Markovnikov hydrobromination and hydrochlorination of alkynes using TMSX (X = Br, Cl)
作者:Dalong Shen、Dehai Cao、Ruizeng Zhang、Peiyuan Bai、Zhenxing Liu
DOI:10.1039/d4ob00608a
日期:——
Markovnikov hydrobromination and hydrochlorination of alkynes were achieved using TMSX (X = Br, Cl) instead of corrosive HX (X = Br, Cl) as the bromination and chlorination reagents. Mn(OAc)2·4H2O was used as the hydrobromination catalyst for electron-neutral/rich alkynes. For the hydrobromination of electron-deficient alkynes and hydrochlorination of alkynes, Zn(OAc)2·2H2O was employed as the catalyst