- Homoleptic mono-, di-, and tetra-iron complexes featuring phosphido ligands: a synthetic, structural, and spectroscopic study
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We report the first series of homoleptic phosphido iron complexes synthesized by treating either the β-diketiminato complex [(Dippnacnac)FeCl2Li(dme)2] (Dippnacnac = HC[(CMe)N(C6H3-2,6-iPr2)]2) or [FeBr2(thf)2] with an excess of phosphides R2PLi (R = tBu, tBuPh, Cy, iPr). Reaction outcomes depend strongly on the bulkiness of the phosphido ligands. The use of tBu2PLi precursor led to an anionic diiron complex 1 encompassing a planar Fe2P2 core with two bridging and two terminal phosphido ligands. An analogous reaction employing less sterically demanding phosphides, tBuPhPLi and Cy2PLi yielded diiron anionic complexes 2 and 3, respectively, featuring a short Fe-Fe interaction supported by three bridging phosphido groups and one additional terminal R2P- ligand at each iron center. Further tuning of the P-substrates bulkiness gave a neutral phosphido complex 4 possessing a tetrahedral Fe4 cluster core held together by six bridging iPr2P moieties. Moreover, we also describe the first homoleptic phosphanylphosphido iron complex 5, which features an iron center with low coordination provided by three tBu2P-P(SiMe3)- ligands. The structures of compounds 1-5 were determined by single-crystal X-ray diffraction and 1-3 by 1H NMR spectroscopy. Moreover, the electronic structures of 1-3 were interrogated using zero-field M?ssbauer spectroscopy and DFT methods.
- Cie?lik, Bart?omiej,Dragulescu-Andrasi, Alina,Grubba, Rafa?,Kaniewska, Kinga,Krzystek, J.,Pikies, Jerzy,Ponikiewski, ?ukasz,Stoian, Sebastian A.,Szynkiewicz, Natalia
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- Preparation method of N-(3-hydroxypropyl)phthalimide and catalyst for method
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The invention relates to a method for preparing N-(3-hydroxypropyl)phthalimide and a catalyst used in the method, the method comprises making phthalimide and allyl alcohol react in a solvent in the presence of an iron-based catalyst, a sodium salt and a potassium salt in an inert atmosphere to obtain N-(3-hydroxypropyl)phthalimide. According to the method, phthalimide and allyl alcohol are used asraw materials, the cheap iron chelate catalyst Fe-PNP is used for replacing an expensive ruthenium catalyst, the product is directly obtained through a reverse Markov addition one-step method, and the method is simple in process, low in cost and high in yield and conversion rate.
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Paragraph 0041-0043
(2020/05/30)
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- Iron(II) Complexes Containing Chiral Unsymmetrical PNP′ Pincer Ligands: Synthesis and Application in Asymmetric Hydrogenations
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Four new chiral PNP′ pincer ligands with a scaffold consisting of a planar chiral ferrocene and a centro chiral aliphatic unit were synthesized and characterized. Treatment of anhydrous FeBr2(THF)2 with 1 equiv of the unsymmetrical chiral PNP′ pincer ligands afforded complexes of the general formula [Fe(PNP′)Br2]. In the solid state these complexes adopt a tetrahedral geometry with the PNP′ ligands coordinated in a ?°2P,N-fashion, as shown by X-ray crystallography. These complexes react with CO in the presence of NaBH4 to yield hydride complexes of the type [Fe(PNP′)(H)(Br)(CO)], which were isolated and tested as catalysts in the asymmetric hydrogenation of ketones. Enantioselectivities of up to 81% ee were obtained.
- Zirakzadeh, Afrooz,Kirchner, Karl,Roller, Alexander,St?ger, Berthold,Widhalm, Michael,Morris, Robert H.
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p. 3781 - 3787
(2016/11/22)
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- Selective hydrogen production from methanol with a defined Iron pincer catalyst under mild conditions
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Molecularly well-defined iron pincer complexes promote the aqueous-phase reforming of methanol to carbon dioxide and hydrogen, which is of interest in the context of a methanol and hydrogen economy. For the first time, the use of earth-abundant iron complexes under mild conditions for efficient hydrogen generation from alcohols is demonstrated. Ironing out the hydrogen: A molecularly defined iron pincer complex is able to catalyze the dehydrogenation of aqueous methanol at low temperatures. This represents a further step towards the implementation of a "methanol/hydrogen economy". Copyright
- Alberico, Elisabetta,Sponholz, Peter,Cordes, Christoph,Nielsen, Martin,Drexler, Hans-Joachim,Baumann, Wolfgang,Junge, Henrik,Beller, Matthias
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supporting information
p. 14162 - 14166
(2014/01/06)
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