Benzoannellated Fenestranes Bearing
<i>para</i>
‐Terphenyl Units
作者:Monika Seifert、Dieter Barth、Dietmar Kuck
DOI:10.1002/ejoc.202101222
日期:2021.12.14
Stericallycrowded tribenzofenestranes, such as the fourfold ortho-phenylated derivatives I and II, were synthesized in an attempt to explore a route to warped nanographenes bearing a tribenzotriquinacene or a [5.5.5.5]fenestrane core.
合成了空间拥挤的三苯并芬烯,例如四重邻苯化衍生物 I 和 II,以尝试探索带有三苯并三喹苯或 [5.5.5.5]芬烯核心的扭曲纳米石墨烯的途径。
Regio- and Chemoselective Kumada–Tamao–Corriu Reaction of Aryl Alkyl Ethers Catalyzed by Chromium Under Mild Conditions
作者:Xuefeng Cong、Huarong Tang、Xiaoming Zeng
DOI:10.1021/jacs.5b08621
日期:2015.11.18
the cross-coupling reactions with arylethers via C-O bond activation have attracted broad interest. However, the functionalizations of C-O bonds are mainly limited to nickel catalysis, and selectivity has long been a prominent challenge when several C-O bonds are present in the one molecule. We report here the first chromium-catalyzed selective cross-coupling reactions of arylethers with Grignard reagents
作为一种环境友好的合成工具,通过 CO 键活化与芳基醚的交叉偶联反应引起了广泛的兴趣。然而,CO 键的功能化主要限于镍催化,当一个分子中存在多个 CO 键时,选择性一直是一个突出的挑战。我们在这里报告了第一个铬催化的芳基醚与格氏试剂通过 CO(烷基)键断裂的选择性交叉偶联反应。在室温下使用简单、廉价的铬 (II) 预催化剂结合亚氨基助剂实现了多种转化。它为高效和选择性地构建官能化芳香醛提供了新途径。
reactive center and a well-defined binding pocket, Au(I) functionalized resorcin[4]arene cavitands have been shown to catalyze molecular transformations. The reactivity profiles that emerge differ from other Au(I) catalysts. The added constraint of a binding pocket gives rise to the possibility that the substrates might have to fit into the resorcinarene pocket; our hypothesis is that substrates that match
We describe here the coupling to transform aryl phosphine derivatives by the cleavage of unactivated C(aryl)–P bonds with chromium catalysis, allowing us to achieve the reaction with alkyl bromides and arylmagnesium reagentsundermildconditions. Mechanistic studies indicate that catalytic cleavage of unactivated C(aryl)–P bonds is due to the in situ formed reactive Cr, followed by transmetalation
functionalized benzaldehydes under mild conditions. This reaction was promoted specifically by a low-cost and simple CrCl2 salt used as a precatalyst, enabling synchronous activations of ortho-C(aryl)–SMe and ortho′-C(aryl)–H bonds to achieve difunctionalization of benzaldimines. This work provided a strategy for accessing arylated, alkylated, and diarylated benzaldehydederivatives as a result of