Chloroacetylenes as Michael acceptors. 3. Mechanism and synthetic utility of enolate reactions with halogenated olefins and chloroacetylenes
作者:Andrew S. Kende、Pawel Fludzinski、John H. Hill
DOI:10.1021/ja00324a025
日期:1984.6
dimethyl-2,6 cyclohexene-2one) avec le trichloroethylene, d'autres ethylenes polyhalogenes et le perchlorobutadiene-1,3. Mecanisme. Lactonisation des adduits perchlorobutenyne. Condensation avec les chloroacetylenes
缩合 d'enolates(例如 l'enolate de Li de la dimethyl-2,6 cyclohexene-2one) avec le trichloroethylene, d'autres ethylenes polyhalogenes et le perchlorobutadiene-1,3。机制。全氯丁烯的内酯化作用。氯乙炔缩合
Heterogeneous catalyzed synthesis of 1,1,1,2-tetrafluoroethane from 1,1,1,2-tetrachloroethane — thermodynamics and reaction pathways
作者:A. Kohne、E. Kemnitz
DOI:10.1016/0022-1139(95)03320-d
日期:1995.11
catalyst. The reactionpathways were derived under different conditions. Fluorinated haloalkanes are formed both by dehydrochlorination/hydrofluorination mechanisms as well as a chlorine/fluorine exchange mechanism. Thus, beside fluorinated alkanes considerable amounts of halo-olefins occur in the product mixture. A survey is given of the reactionpathways showing their dependence on the reaction conditions
Catalytic fluorination of 1,1,1-trifluoro-2-chloro-ethane in the presence of oxygen over chromium based catalyst doped or not by zinc supported over partially fluorinated alumina
The addition of zinc in low amount to chromium based catalyst supported over partially fluorinated alumina has a positive effect for the fluorination reaction of CF3CH2Cl in the presence of dioxygen in order to prevent the catalyst deactivation. However, under these operating conditions, the Deacon reaction by reaction with HCl produced by Cl/F exchanges could be involved. The formation of various
Catalytic Cross-Metathesis Reactions That Afford <i>E</i>- and <i>Z</i>-Trisubstituted Alkenyl Bromides: Scope, Applications, and Mechanistic Insights
作者:Tobias Koengeter、Can Qin、Binh Khanh Mai、Qinghe Liu、Yucheng Mu、Peng Liu、Amir H. Hoveyda
DOI:10.1021/jacs.2c13289
日期:2023.2.15
(MAP) complexes, one purchasable and the other accessible by well-established protocols. Substrates, such as feedstock trisubstituted olefins, can be purchased; the alkenyl bromide reagents are commercially available or can be prepared in two steps in a multigram scale. The catalytic process can be used to generate products that contain polar moieties, such as an amine or an alcohol, or sterically hindered
末端具有溴化物和甲基的立体化学定义的三取代烯烃可以通过催化交叉偶联轻松地立体保留衍生,从而提供在许多生物活性天然产物中发现的不饱和片段。生成此类实体的直接方法是通过立体控制催化交叉复分解(CM)。然而,这样的方法很少。在这里,我们提出了三-、 Z-或E-二或单取代烯烃与Z-或E -2-溴-2-丁烯之间的CM立体保留策略,提供了各种E-或Z-三取代烯基溴。大多数转化是由两种钼单芳氧基吡咯烷 (MAP) 络合物催化,一种可购买,另一种可通过完善的方案获得。底物,例如原料三取代烯烃,可以购买;烯基溴试剂是可商购的或者可以以多克规模分两步制备。催化过程可用于生成含有极性部分的产物,例如胺或醇,或α-或β-支化的空间位阻烯烃。该方法的实用性通过 phomactin A 不饱和片段的简短立体控制合成和龙涎香的简明全合成得到强调。这些研究的一个意想不到的结果是发现了小分子烯烃在烯烃复分解反应中的新作用。