本工作通过理论计算和详细的实验方法探讨了2-叔丁基py(1)的溴化机理,该区域选择性地提供了单溴,二溴,三溴和四溴py 。在存在铁粉的情况下,可以将溴原子引导至K区(5-和9-位),而不是反应性更高的6和8位。在此过程中,FeBr 3在释放空间位阻或降低重排的活化能方面起着重要作用。中间体溴py衍生物经分离并经1确证1 H NMR光谱,质谱和元素分析。关于取代位置的进一步证据来自一系列芳基取代的derivatives衍生物,这些衍生物是通过Suzuki-Miyaura交叉偶联反应与4-甲氧基-苯基硼酸反应而得自相应的溴py。所有依赖位置的芳基官能化pyr衍生物均具有单X射线衍射,1 H / 13 C NMR,FT-IR和MS表征,并提供了直接的证据来支持我们的结论。此外,通过荧光和吸收以及荧光寿命测量证实了一系列化合物的光物理性质。
Synthesis of Highly Twisted, Nonplanar Aromatic Macrocycles Enabled by an Axially Chiral 4,5-Diphenylphenanthrene Building Block
作者:Yuanming Li、Akiko Yagi、Kenichiro Itami
DOI:10.1021/jacs.9b13549
日期:2020.2.12
The synthesis, structures, and properties of highly twisted, nonplanar aromatic macrocycles are described. These macrocycles with an approximately 90° twist angle were synthesized by an effective synthetic approach through a quadruple Suzuki-Miyaura coupling of 4,5-bisarylphenanthrene as a novel axially chiral nonplanar buildingblock. By varying the cross-coupling partner as the spacer, a family of
Extremely Active Organocatalysts Enable a Highly Enantioselective Addition of Allyltrimethylsilane to Aldehydes
作者:Philip S. J. Kaib、Lucas Schreyer、Sunggi Lee、Roberta Properzi、Benjamin List
DOI:10.1002/anie.201607828
日期:2016.10.10
The enantioselective allylation of aldehydes to form homoallylic alcohols is one of the most frequently used carbon–carbon bond‐forming reaction in chemical synthesis and, for several decades, has been a testing ground for new asymmetric methodology. However, a general and highlyenantioselective catalytic addition of the inexpensive, nontoxic, air‐ and moisture‐stable allyltrimethylsilane to aldehydes
Bis(carbazol-9-yl)phenyl end-caped polyaromatics as solution-processed deep blue fluorescent emitters for simple structure solution-processed electroluminescent devices
have been designed and synthesized in this contribution for blueOLED application. The molecules are constructed from basic building blocks of blue chromophores (anthracene or pyrene derivatives) and end-capped with charge transporting (1,3-phenylene)bis(3,6-di-tert-butyl-9H-carbazole) units which provided the tunable emission in the blue spectral range. Their optical, electrochemical, photophysical
O-doped nanographenes derived from the π-extension of pyrene. The derivatives are highly fluorescent and feature low oxidation potentials. Using electrooxidation, crystals of cationic mixed-valence (MV) complexes were grown in which the organic salts organize into face-to-face π-stacks, a favorable solid-state arrangement for organic electronics. Variable-temperature electron paramagnetic resonance (EPR)