21244-24-6Relevant articles and documents
Desymmetrization of an Octahedral Coordination Complex Inside a Self-Assembled Exoskeleton
Johnstone, Mark D.,Schwarze, Eike K.,Ahrens, Jennifer,Schwarzer, Dirk,Holstein, Julian J.,Dittrich, Birger,Pfeffer, Frederick M.,Clever, Guido H.
, p. 10791 - 10795 (2016)
The synthesis of a centrally functionalized, ribbon-shaped [6]polynorbornane ligand L that self-assembles with PdIIcations into a {Pd2L4} coordination cage is reported. The shape-persistent {Pd2L4} cage contains two axial cationic centers and an array of four equatorial H-bond donors pointing directly towards the center of the cavity. This precisely defined supramolecular environment is complementary to the geometry of classic octahedral complexes [M(XY)6] with six diatomic ligands. Very strong binding of [Pt(CN)6]2?to the cage was observed, with the structure of the host–guest complex {[Pt(CN)6]@Pd2L4} supported by NMR spectroscopy, MS, and X-ray data. The self-assembled shell imprints its geometry on the encapsulated guest, and desymmetrization of the octahedral platinum species by the influence of the D4h-symmetric second coordination sphere was evidenced by IR spectroscopy. [Fe(CN)6]3?and square-planar [Pt(CN)4]2?were strongly bound. Smaller octahedral anions such as [SiF6]2?, neutral carbonyl complexes ([M(CO)6]; M=Cr, Mo, W) and the linear [Ag(CN)2]?anion were only weakly bound, showing that both size and charge match are key factors for high-affinity binding.
Catalytic SNAr Hydroxylation and Alkoxylation of Aryl Fluorides
Kang, Qi-Kai,Li, Ke,Li, Yuntong,Lin, Yunzhi,Shi, Hang,Xu, Lun
supporting information, p. 20391 - 20399 (2021/08/13)
Nucleophilic aromatic substitution (SNAr) is a powerful strategy for incorporating a heteroatom into an aromatic ring by displacement of a leaving group with a nucleophile, but this method is limited to electron-deficient arenes. We have now established a reliable method for accessing phenols and phenyl alkyl ethers via catalytic SNAr reactions. The method is applicable to a broad array of electron-rich and neutral aryl fluorides, which are inert under classical SNAr conditions. Although the mechanism of SNAr reactions involving metal arene complexes is hypothesized to involve a stepwise pathway (addition followed by elimination), experimental data that support this hypothesis is still under exploration. Mechanistic studies and DFT calculations suggest either a stepwise or stepwise-like energy profile. Notably, we isolated a rhodium η5-cyclohexadienyl complex intermediate with an sp3-hybridized carbon bearing both a nucleophile and a leaving group.
Simple and rapid p-methoxybenzylation of hydroxy and amide groups at room temperature by NaOt-Bu and DMSO
Hamada, Shohei,Sugimoto, Koichi,Iida, Masashi,Furuta, Takumi
supporting information, (2019/11/13)
The p-methoxybenzylation of hydroxy and amide groups by p-methoxybenzyl chloride utilizing NaOt-Bu in DMSO is described. p-Methoxybenzylation of sterically hindered menthol using NaOt-Bu in DMSO proceeded faster than the commonly used methods which use Na
Alkoxide-Catalyzed Hydrosilylation of Cyclic Imides to Isoquinolines via Tandem Reduction and Rearrangement
Wu, Xiaoyu,Ding, Guangni,Yang, Liqun,Lu, Wenkui,Li, Wanfang,Zhang, Zhaoguo,Xie, Xiaomin
supporting information, p. 5610 - 5613 (2018/09/12)
An alkoxide-catalyzed hydrosilylation of cyclic imides to isoquinolines was realized via tandem reduction and rearrangement. Using TMSOK as the catalyst and (EtO)2MeSiH as the reductant, a series of cyclic imides containing different functional groups were reduced to the corresponding 3-aryl isoquinolines in moderate to good yields. The scenario of the reaction pathway was supposed to involve the reduction of imides to ω-hydroxylactams, which underwent rearrangement in the presence of a base catalyst, and then the carbonyl reduction, followed by siloxy elimination.