Synthesis of a new calix[n]pyrrole: meso-pentaspirocyclohexyl calix[5]pyrrole
作者:Mercedes Bedolla-Medrano、Luis Chacón-García、Claudia A. Contreras-Celedón、Jesús Campos-García
DOI:10.1016/j.tetlet.2010.11.007
日期:2011.1
We describe the first synthesis of the novel meso-pentaspirocyclohexyl calix[5]pyrrole 2b. Anion–guest properties of the new compound were evaluated with respect to fluoride, chloride, and bromide tetrabutylammonium salts by 1H NMR titration techniques in deuterated dichloromethane at 22 °C by following the induced shifts in the NH resonances upon complexation.
我们描述了新型的介孔五环环己基杯[5]吡咯2b的首次合成。通过1 H NMR滴定技术在氘化的二氯甲烷中于22°C下通过络合后NH共振的诱导位移,评估了该化合物相对于氟化物,氯化物和溴化物四丁基铵盐的阴离子-客体性能。
Calix[4]pyrrolato Aluminates: The Effect of Ligand Modification on the Reactivity of Square‐Planar Aluminum Anions
作者:Fabian Ebner、Philipp Mainik、Lutz Greb
DOI:10.1002/chem.202005493
日期:2021.3.17
unusual oxidation or valence states. The recently reported methyl‐calix[4]pyrrolato aluminate established the effect of forcing a tetrahedral aluminum anion into a square‐planar coordination mode. However, the generality of this structural motif and any consequence of ligand modification remained open. Herein, a systematic ligand screening was launched, and the class of square‐planar aluminum anions was
结构约束是一种有吸引力的工具,可以在不需要异常氧化或价态的情况下修改 p 区元素特性。最近报道的甲基杯[4]吡咯铝酸盐建立了迫使四面体铝阴离子进入方形平面配位模式的效应。然而,这种结构基序的普遍性和配体修饰的任何后果仍然是开放的。在此,启动了系统的配体筛选,并通过两种衍生物扩展了方形平面铝阴离子的类别,这两种衍生物在杯[4]吡咯配体处的内消旋取代方面有所不同。引人注目的是,这种修饰引发了对σ-供体的路易斯酸性结合模式与与羰基的铝配体合作结合模式的偏好的相反趋势。通过计算和键分析,可以深入了解这些违反直觉的实验观察的起源。重要的是,这一原理可能允许利用模式选择性结合来控制催化速率。
Alkali-metal- and halide-free dinuclear mixed-valent samarium and europium complexes
作者:Nishya F. M. Mukthar、Nathan D. Schley、Gaël Ung
DOI:10.1039/d0dt01095b
日期:——
The synthesis of alkali metal- and halide-free mixed valent dilanthanide complexes supported by a calix[4]pyrrole ligand is described. Bond activation using both a base and one-electron reductant is showcased.
Dioxygen Activation and Pyrrole α‐Cleavage with Calix[4]pyrrolato Aluminates: Enzyme Model by Structural Constraint
作者:Lukas Maximilian Sigmund、Christopher Ehlert、Markus Enders、Jürgen Graf、Ganna Gryn'ova、Lutz Greb
DOI:10.1002/anie.202104916
日期:2021.7.5
describes the reaction of triplet dioxygen with the porphyrinogenic calix[4]pyrrolato aluminates to alkylperoxido aluminates in high selectivity. Multiconfigurational quantum chemical computations disclose the mechanism for this spin-forbidden process. Despite a negligible spin–orbit coupling constant, the intersystem crossing (ISC) is facilitated by singlet and tripletstate degeneracy and spin–vibronic
Syntheses of Calix[4]Pyrroles by Amberlyst-15 Catalyzed Cyclocondensations of Pyrrole with Selected Ketones
作者:Shive Chauhan、Bhaskar Garg、Tanuja Bisht
DOI:10.3390/12112458
日期:——
A facile and efficient protocol is reported for the synthesis of calix[4]pyrrolesand N-confused calix[4]pyrroles in moderate to excellent yields by reaction of dialkyl orcycloalkyl ketones with pyrrole catalyzed by reusable AmberlystTM-15 under eco-friendlyconditions.