Solvent-free preparation of α,α-dichloroketones with sulfuryl chloride
作者:Dewei Tu、Juan Luo、Wengao Jiang、Qiang Tang
DOI:10.1016/j.tetlet.2021.153335
日期:2021.9
An efficient and facile method is reported for the synthesis of a series of α,α-dichloroketones. The direct dichlorination of methyl ketones and 1,3-dicarbonyls using an excess amount of sulfuryl chloride affords the corresponding -dichloro compounds in moderate to excellent yields. Moreover, the protocol features high yields, broad substrate scope, and simple reaction conditions without using any
New, Efficient Synthesis of<font>α</font>-Chloroketones Using SiCl<sub>4</sub>/Urea–Hydrogen Peroxide or SiCl<sub>4</sub>/Iodosylbenzene Reagent Systems
作者:Abdel Aziz S. El-Ahl、Akram H. Elbeheery、Fathy A. Amer
DOI:10.1080/00397911.2010.487173
日期:2011.4.19
Abstract Alkyl aryl ketones on treatment with SiCl4/urea–hydrogen peroxide (UHP) or SiCl4/iodosylbenzne reagent systems afforded α-chloroketones in excllent yields, while ketones with higher enol content provide exclusively α,α-dichloroketones under exceedingly mild conditions. The reaction proceeds via the initial formation of silyl enolethers. A polarized chlorine intermediate that resulted from
N-halosuccinimides (NXS) under mild conditions with short reaction times. Methyl arylketones were converted into α-halo and α,α-dihaloketones, depending on the quantity of NXS used. Ketones with activated aromatic rings were selectively halogenated, however in some cases mixtures of α-halogenated ketone and ring-halogenated ketones were obtained. Activated aromatics were regioselectively ring halogenated
布朗斯台德酸性离子液体 1-甲基-3-(4-磺丁基)咪唑鎓三氟甲磺酸盐 [BMIM(SO(3)H)][OTf] 被证明可有效用作溶剂和催化剂,用于活化有机化合物与 N 的卤化-卤代琥珀酰亚胺 (NXS) 在温和条件下反应时间短。甲基芳基酮转化为 α-卤代酮和 α,α-二卤代酮,这取决于所用 NXS 的数量。具有活化芳环的酮被选择性卤化,但在某些情况下,会得到 α-卤化酮和环卤化酮的混合物。活化的芳烃被区域选择性环卤化以得到单和二卤取代的产物。[BMIM(SO(3)H)][OTf] 离子液体 (IL-A) 在代表性的单卤化反应中成功重复使用八次,效率没有明显降低。还介绍了该 IL 中有效的卤化放大。反应性趋势和观察到的化学和区域选择性表明这些 IL 促进的卤代官能化反应中存在 ET 过程。
Halogenation Using Quaternary Ammonium Polyhalides. XXXII. Dichlorination of Aromatic Acetyl Derivatives with Benzyltrimethylammonium Tetrachloroiodate
The reaction of aromatic acetyl derivatives with 2 molar amounts of benzyltrimethylammonium tetrachloroiodate in acetic acid at 70 °C for several hours gave dichloroacetyl derivatives in good yields.
芳族乙酰衍生物与 2 摩尔量的四氯碘酸苄基三甲基铵在 70 °C 的乙酸中反应几个小时,以良好的收率得到二氯乙酰衍生物。