Synthesis of poly-functionalized pyrazoles under Vilsmeier-Haack reaction conditions
作者:Aleksandr V. Popov、Valentina A. Kobelevskaya、Ludmila I. Larina、Igor B. Rozentsveig
DOI:10.24820/ark.5550190.p010.934
日期:——
Synthesis of 1,3-disubstituted 5-chloro-1H-pyrazole-4-carbaldehydes was achieved by formylation of the corresponding 5-chloro-1H-pyrazoles under Vilsmeier-Haack conditions.
The reactions of trichloromethanesulfonyl chloride with trimethylsilyl enol ethers of acetophenones in the presence of a ruthenium(II) phosphine complex gave 1-aryl-3,3-dichloropropen-1-one together with α-chloroacetophenones. The product ratio depended on the substituent on the aromatic ring of the silyl enol ether. The reactions of carbon tetrachloride with the silyl enol ethers under similar conditions
An enantioselective, catalytic trichloromethylation of 2-acyl imidazoles and 2-acylpyridines is reported. Several products are formed with enantiomeric excess of ≥99%. In this system, a chiral iridium complex serves a dual function, as a catalytically active chiral Lewis acid and simultaneously as a precursor for an in situ assembled visible-light-triggered photoredox catalyst.
Functionalized β,β-dichloroenones and β,β-dibromoenones as versatile building blocks: Synthesis and transformations
作者:Dengke Li
DOI:10.1016/j.tetlet.2021.153551
日期:2021.12
functionalized β,β-dichloroenones and β,β-dibromoenones was achieved via the Fe-catalyzed radical induced reactionbetween silyl enol ethers and carbontetrachloride, bromotrichloromethane or carbon tetrabromide in moderate to good yields. This reaction proceeds through addition of the trichloromethyl or tribromomethyl radical group to the CC bond of the silyl enol ethers and subsequent base-induced elimination
通过甲硅烷基烯醇醚与四氯化碳、溴三氯甲烷或四溴化碳之间的 Fe 催化自由基诱导反应,以中等至良好的收率实现了功能化β,β-二氯烯酮和β,β-二溴烯酮的高效一步合成。该反应通过将三氯甲基或三溴甲基自由基添加到甲硅烷基烯醇醚的 C C 键上并随后在温和条件下进行碱诱导消除来进行。
Synthesis of 5-Chloroisoxazoles Derived from 2,2-Dichlorovinyl Ketones
作者:A. V. Popov、V. A. Kobelevskaya、I. D. Titov、L. I. Larina、I. B. Rozentsveig
DOI:10.1134/s107042802011010x
日期:2020.11
Abstract The reactions of 2,2-dichlorovinyl ketones with hydroxylamine hydrochloride give the corresponding oximes. The subsequent heterocyclization of the latter under the action of t-BuOK in t-BuOH results in selective formation of 5-chloro-3-alkyl- or 5-chloro-3-aryl-substituted isoxazoles in good yields.