Strained azabora[2]ferrocenophanes

Bhattacharjee, Hridaynath; Dey, Subhayan; Zhu, Jianfeng; Sun, Wei; Müller, Jens

doi:10.1039/c8cc02965b

Cited by 6 publications

(3 citation statements)

References 33 publications

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“…Therefore, there is some open space on the opposite side of the bridge, where we hypothesized catalysis can take place. The tilt is smaller compared to ferrocenophanes with bridges consisting of two atoms, where angles around 22° have been reported [ 87 ]. Ferrocenophanes with a bridge consisting of only one atom exhibit angles between 27 and 38°, putting a substantial strain on the system [ 79 , 88 ].…”

Section: Resultsmentioning

confidence: 99%

Ferrocenophanium Stability and Catalysis

et al. 2023

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Ferrocenium catalysis is a vibrant research area, and an increasing number of ferrocenium-catalyzed processes have been reported in the recent years. However, the ferrocenium cation is not very stable in solution, which may potentially hamper catalytic applications. In an effort to stabilize ferrocenium-type architectures by inserting a bridge between the cyclopentadienyl rings, we investigated two ferrocenophanium (or ansa-ferrocenium) cations with respect to their stability and catalytic activity in propargylic substitution reactions. One of the ferrocenophanium complexes was characterized by single crystal X-ray diffraction. Cyclic voltammetry experiments of the ferrocenophane parent compounds were performed in the absence and presence of alcohol nucleophiles, and the stability of the cations in solution was judged based on the reversibility of the electron transfer. The experiments revealed a moderate stabilizing effect of the bridge, albeit the effect is not very pronounced or straightforward. Catalytic propargylic substitution test reactions revealed decreased activity of the ferrocenophanium cations compared to the ferrocenium cation. It appears that the somewhat stabilized ferrocenophanium cations show decreased catalytic activity.

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Section: Resultsmentioning

confidence: 99%

Ferrocenophanium Stability and Catalysis

et al. 2023

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“…When 2 equiv of diphenylsilane was used, 5 persisted as the major product in 70% spectroscopic yield with the remaining products assumed to be linear species, which eluded unambiguous characterization. Although there are several examples of metallocenophanes with nitrogen-containing ansa -bridges (excepting ferrocene-based N-heterocyclic carbenes and numerous examples where the 1,1′-bisamino-, amido-, and imido- ferrocene moiety has been used as a chelating ligand), − compound 5 is of particular interest since it is, to the best of our knowledge, the first example with a N–Si–N bridging unit.…”

Section: Resultsmentioning

confidence: 99%

Ferrocene-Containing Polycarbosilazanes via the Alkaline-Earth-Catalyzed Dehydrocoupling of Silanes and Amines

et al. 2019

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We report the use of the alkaline-earth (Ae) metalcatalyzed dehydrocoupling of silanes and amines for the synthesis of ferrocene-containing polycarbosilazanes. The barium complex [Ba(N(SiMe 3 ) 2 ) 2 •(THF) 2 ] catalyzed the dehydrocoupling of the hydrosilane FeCp(CpSiPhH 2 ) (1) with 1,4-(H 2 NCH 2 ) 2 C 6 H 4 under mild conditions to give a polycarbosilazane with pendant ferrocene groups. The polymer could be readily cross-linked by the addition of phenylsilane to the unquenched reaction mixture. Welldefined polycarbosilazanes with ferrocene in the main chain were also obtained from the dehydrocoupling of hydrosilanes Fe(Cp-(SiPhH 2 )) 2 (3) and Fe(Cp(SiMe 2 H)) 2 (IX) with 1,4-(H(Me)-NCH 2 ) 2 C 6 H 4 and 1,4-(H 2 NCH 2 ) 2 C 6 H 4 , respectively. Crystalline monomeric analogues, FeCp(Cp(SiPh(NHBn) 2 )) (2, Bn = CH 2 (C 6 H 5 )), and Fe(Cp(SiPh(NHBn) 2 )) 2 (4), were also obtained via the dehydrocoupling benzylamine with 1 and 3, respectively. The barium-catalyzed dehydrocoupling of diaminoferrocene with Ph 2 SiH 2 or Ph(Rc)SiH 2 (6, Rc = (C 5 H 4 )Ru(C 5 H 5 )) did not result in polymer, but instead in the formation of the silazanebridged ansa-[3]ferrocenophanes (Fe(η-C 5 H 4 NH) 2 SiPh 2 ) (5) and (Fe(η-C 5 H 4 NH) 2 SiPh(Rc)) (7), respectively. Both polymeric and molecular products were electrochemically investigated, and the polymers proved to be promising precursors to magnetic iron-containing ceramics in yields of up to 64%.

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“…Although there are several synthetic strategies reported for compound 1, [73][74][75][76][77] due to low obtainable yields, 73,[75][76][77] and apparently impure final product, 73,74,76,77 a newly reported pathway, which involves Staudinger-type reaction on 1,1′-azidobromoferrocene (Scheme 1A), 78 was used for this compound. Compound 1 was initially purified by column chromatography, followed by a flask-to-flask sublimation, which resulted in bright colored golden yellow crystals, which were found suitable for characterization by single crystal X-ray diffraction (Fig.…”

Section: Synthesis and Properties Of Ferrocene Bridged Pn-ligandsmentioning

confidence: 99%