Absolute asymmetric synthesis. III. Hindered rotation about aryl-ethylene bonds in the excited states of diaryl ethylenes. Structural effects on the asymmetric synthesis of 2- and 4-substituted hexahelicenes
作者:Martin Jakubec、Indrajit Ghosh、Jan Storch、Burkhard König
DOI:10.1002/chem.201904169
日期:2020.1.7
Herein, a visible-light photochemical approach for practical helicene functionalization at very mild reaction conditions is described. The photochemical reactions allow for the regiospecific and innate late-stage functionalization of helicenes and are easily executed either through the activation of C(sp2 )-Br bonds in helicenes using K2 CO3 as inorganic base or direct C(sp2 )-H helicene bond functionalization
Chiral Emissive Lanthanide Complexes from Enantiopure [6]Helicene‐bis(pyrazolyl)‐pyridine Ligands
作者:Alexandre Abhervé、Maurizio Mastropasqua Talamo、Nicolas Vanthuyne、Francesco Zinna、Lorenzo Di Bari、Maxime Grasser、Boris Le Guennic、Narcis Avarvari
DOI:10.1002/ejic.202200010
日期:2022.4.20
The use of enantiopure bis(pyrazolyl)-pyridine-[6]helicene ligands allowed the preparation of chiral emissive Eu(III) and Yb(III) complexes. Remarkably, the Eu(III) complex shows CPL activity despite the remote position of the helicene unit with respect to the coordination sphere of the metal ion.
synthetic strategy toward phosphahelicenes containing a terminal phosphinine ring has been explored. The 4-phenyl-6-methyl-2-phospha[7]helicene was prepared from starting 2-bromobenzo[c]phenanthrene in 12% overall yield in 12 steps. The synthetic approach involves introduction of the phosphorus function prior to photocyclization forming the final helicene skeleton, followed by the formation of a phosphorus
已经探索了针对含有末端膦环的磷酸螺旋烯的合成策略。4-phenyl-6-methyl-2-phospha[7]helicene 由起始 2-溴苯并[ c ]菲在 12 个步骤中以 12% 的总产率制备。合成方法包括在光环化形成最终的螺旋骨架之前引入磷功能,然后形成磷六环。通过 X 射线晶体学证实了具有末端膦环的第一个 phosphahelicene 的结构。
Inherently chiral helicene-substituted thioalkyl porphyrazine complexes: synthesis and electronic and chiroptical properties
The chiral Ni(II) and Pd(II) complexes of [6]helicene thioethyl porphyrazine have been synthesized and their spectroscopic, electrochemical, and chiropticalproperties have been investigated by experimental and computational analyses. In these compounds, the tetrapyrrole macrocycle is β-substituted with an inherently chiral extended aromatic moiety potentially suitable to establish attractive π–π interactions
Helicenic N-heterocyclic carbene copper(<scp>i</scp>) complex displaying circularly polarized blue fluorescence
作者:Etienne S. Gauthier、Dominika Kaczmarczyk、Samuel Del Fré、Ludovic Favereau、Elsa Caytan、Marie Cordier、Nicolas Vanthuyne、J. A. Gareth Williams、Monika Srebro-Hooper、Jeanne Crassous
DOI:10.1039/d2dt01925f
日期:——
Enantiopure copper(I) chloride complexes bearing a monodentate N-(carbo[6]helicenyl)–NHC ligand have been prepared and characterized experimentally and computationally. Their high stability enables the stereochemistry to be probed by X-ray crystallography and NMR spectroscopy. The resolved enantiomeric complexes emit circularly polarized blue fluorescence with glum ∼1.3 × 10−3 in solution. The photophysical
已经制备了带有单齿N -(carbo[6]helicenyl)-NHC 配体的对映纯氯化铜 ( I ) 配合物,并通过实验和计算进行了表征。它们的高稳定性使立体化学能够通过 X 射线晶体学和 NMR 光谱学进行探测。解析的对映体复合物在溶液中发出圆偏振蓝色荧光,g lum ~1.3 × 10 -3。这些系统的光物理和手性光学特性及其以螺旋为中心的起源,与有机螺旋烯-苯并咪唑前体前体前体的那些相似,尽管与配体相比,复合物优先观察到反向轴向手性构型。