The palladium-catalyzed reaction of γ-silylated allyl acetates with water in the presence of CsF induces a previously unprecedented 1,2-shift of a substituent on silicon to produce allylsilanes in situ. The catalytic activity of the palladium increased when using an electron-poor phosphine ligand possessing fluorinated substituents. Further investigation of the reaction revealed that the approximate
Nickel-Catalyzed Csp<sup>2</sup>–Csp<sup>3</sup>Bond Formation via C–F Bond Activation
作者:Yee Ann Ho、Matthias Leiendecker、Xiangqian Liu、Chengming Wang、Nurtalya Alandini、Magnus Rueping
DOI:10.1021/acs.orglett.8b02351
日期:2018.9.21
A nickel-catalyzed cross coupling of aryl fluorides via C–Fbondactivation has been developed. The alkylation method allows selective replacement of aryl fluorides by alkyl groups and enables the synthesis of diverse and otherwise difficult to access scaffolds in good yields.
We report nickel-catalyzed cross-coupling of methoxyarenes with alkylmagnesium halides, in which a methoxy group is eliminated. A wide range of alkyl groups, including those bearing β-hydrogens, can be introduced directly at the ipso position of anisole derivatives. We demonstrate that the robustness of a methoxy group allows this alkylation protocol to be used to synthesize elaborate molecules by
我们报告了镍催化的甲氧基芳烃与烷基卤化镁的交叉偶联,其中甲氧基被消除。广泛的烷基,包括那些带有 β-氢的烷基,可以直接在苯甲醚衍生物的 ipso 位置引入。我们证明甲氧基的稳健性允许该烷基化方案通过将其与传统的交叉偶联反应或氧化转化相结合来合成复杂的分子。这种方法的成功取决于使用烷基碘化镁,而不是氯化物或溴化物,这突出了卤化物在使用格氏试剂进行催化反应中的重要性。
[4 + 2] Annulation of Donor–Acceptor Cyclopropanes with Acetylenes Using 1,2-Zwitterionic Reactivity
作者:Roman A. Novikov、Anna V. Tarasova、Dmitry A. Denisov、Denis D. Borisov、Victor A. Korolev、Vladimir P. Timofeev、Yury V. Tomilov
DOI:10.1021/acs.joc.7b00209
日期:2017.3.3
of donor–acceptor cyclopropanes with acetylenes under the effect of anhydrous GaCl3 using 1,2-zwitterion reactivity was elaborated. The reaction opens access to substituteddihydronaphthalenes, naphthalenes, and other fused carbocycles. The direction of the reaction can be efficiently controlled by temperature.
C–F Activation for C(sp<sup>2</sup>)–C(sp<sup>3</sup>) Cross-Coupling by a Secondary Phosphine Oxide (SPO)-Nickel Complex
作者:Valentin Müller、Debasish Ghorai、Lorena Capdevila、Antonis M. Messinis、Xavi Ribas、Lutz Ackermann
DOI:10.1021/acs.orglett.0c02609
日期:2020.9.4
A secondary phosphine oxide (SPO)-nickel catalyst allowed the activation of otherwise inert C–F bonds of unactivated arenes in terms of challenging couplings with primary and secondary alkyl Grignard reagents. The C–F activation is characterized by mild reaction conditions and high levels of branched selectivity. Electron-rich and electron-deficient arenes were suitable electrophiles for this transformation