717-74-8Relevant articles and documents
Synthesis, characterization, and alkyne trimerization catalysis of a heteroleptic two-coordinate FeI complex
Lipschutz, Michael I.,Chantarojsiri, Teera,Dong, Yuyang,Tilley, T. Don
, p. 6366 - 6372 (2015)
The synthesis of the first heteroleptic, two-coordinate FeI complex IPr-Fe-N(SiMe3)DIPP (1) (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene; DIPP = 2,6-iPr2-C6H3) is reported. Protonation of the FeII bis(amido) complex Fe[N(SiMe3)DIPP]2 followed by addition of IPr and reduction by potassium graphite in a one-pot reaction results in good yields of 1. The redox activity of 1 and comparison between 1 and its reduction product by 57Fe M?ssbauer spectroscopy are discussed, and the reduction was found to be metal-based rather than ligand-based. The activity of 1 toward the catalytic cyclotrimerization of terminal and internal alkynes is described.
Synthesis methodology, stability, acidity, and catalytic behavior of the 18 × 10 member ring pores ITQ-33 zeolite
Moliner, Manuel,Diaz-Cabanas, Maria J.,Fornes, Vicente,Martinez, Cristina,Corma, Avelino
, p. 101 - 109 (2008)
We used a flexible organic structure-directing agent (OSDA) and high-throughput (HT) synthesis techniques to explore a large composition region. A zeolite with the largest pores reported to date (ITQ-33) was found under very unusual synthesis conditions, together with other known structures. A second HT experimental design allowed, finally synthesizing pure ITQ-33. We studied the thermal and hydrothermal stability and acid properties of the zeolite. We investigated the role of pore diameter on zeolite acid strength by comparing the 18-ring pore (ITQ-33) with a 12-MR pore (ITQ-17) zeolite with the same framework composition. Finally, we compared the catalytic properties of ITQ-33 for reactant molecules of different sizes with those of 12-MR (Beta) and 14-MR (UTD-1) zeolites.
Detailed kinetic study of cumene isopropylation in a liquid-liquid biphasic system using acidic chloroaluminate ionic liquids
Joni,Schmitt,Schulz,Lotz,Wasserscheid
, p. 401 - 409 (2008)
A kinetic study of cumene isopropylation has been carried out using the acidic ionic liquid 1-ethyl-3-methylimidazolium chloride ([EMIM]Cl)/AlCl3 (molar ratio 1:2) as the catalyst phase in a semi-batch liquid-liquid biphasic reaction system. Kinetic models representing the alkylation reaction network have been established based on reaction temperature and propylene partial pressure variations. By comparing the results of the kinetic models with the measured concentrations in the liquid organic phase, the importance of the different product solubilities in the acidic ionic liquid became evident. Correction of the product concentrations in the organic phase based on a COSMO-RS calculation of the relative product solubilities in the acidic ionic liquid [EMIM][Al2Cl7] gave a remarkably good prediction of the reaction kinetics by the kinetic model. These findings demonstrate the suitability of COSMO-RS to predict the relative solubilities of different aromatic compounds in highly reactive catalytic systems.
Two derivatives of phenylpyridyl-fused boroles with contrasting electronic properties: Decreasing and enhancing the electron accepting ability
He, Jiang,Rauch, Florian,Krummenacher, Ivo,Braunschweig, Holger,Finze, Maik,Marder, Todd B.
, p. 355 - 361 (2021/01/11)
Two derivatives of phenylpyridyl-fused boroles were prepared via functionalization of the pyridyl groups, namely to an electron-rich dihydropyridine moiety (compound 1) and an electron-deficient N-methylpyridinium cation (compound 2). Due to strong conjugation between the dihydropyridine moiety and the boron atom, the reduction potential of compound 1 shifts cathodically. In contrast, compound 2 exhibits three reduction processes with a first reversible reduction potential anodically shifted in comparison to its precursor (TipPBB2) or the non-borylated framework 1-methyl-2-phenylpyridin-1-ium triflate (3). The significantly anodically shifted reduction potential indicates the extreme electron deficiency of compound 2, which also leads to the reversible coordination of THF. Photophysical properties of both compounds in different solvents were investigated. Theoretical studies further support the strong conjugation in the ground state of compound 1 and the electron-deficient property of compound 2.
Catalytic hydrodebromination of aryl bromides by cobalt tetra-butyl porphyrin complexes with EtOH
Chen, Chen,Zuo, Huiping,Chan, Kin Shing
, p. 510 - 517 (2019/01/04)
Hydrodebromination of aryl bromides catalyzed by electron rich and sterically unhindered cobalt 5,10,15,20-tetrabutylporphyrin was achieved at mild conditions in good yields employing EtOH as the hydrogen source. The catalytic efficiency was enhanced compared with previously reported by cobalt tetra-aryl porphyrin catalysts. A revised mechanism of single electron transfer was proposed.
Hydrodehalogenation of Aryl Halides through Direct Electrolysis
Ke, Jie,Wang, Hongling,Zhou, Liejin,Mou, Chengli,Zhang, Jingjie,Pan, Lutai,Chi, Yonggui Robin
supporting information, p. 6911 - 6914 (2019/05/10)
A catalyst- and metal-free electrochemical hydrodehalogenation of aryl halides is disclosed. Our reaction by a flexible protocol is operated in an undivided cell equipped with an inexpensive graphite rod anode and cathode. Trialkylamines nBu3N/Et3N behave as effective reductants and hydrogen atom donors for this electrochemical reductive reaction. Various aryl and heteroaryl bromides worked effectively. The typically less reactive aryl chlorides and fluorides can also be smoothly converted. The utility of our method is demonstrated by detoxification of harmful pesticides and hydrodebromination of a dibrominated biphenyl (analogues of flame-retardants) in gram scale.
Dual Roles for Potassium Hydride in Haloarene Reduction: CSNAr and Single Electron Transfer Reduction via Organic Electron Donors Formed in Benzene
Barham, Joshua P.,Dalton, Samuel E.,Allison, Mark,Nocera, Giuseppe,Young, Allan,John, Matthew P.,McGuire, Thomas,Campos, Sebastien,Tuttle, Tell,Murphy, John A.
supporting information, p. 11510 - 11518 (2018/09/12)
Potassium hydride behaves uniquely and differently than sodium hydride toward aryl halides. Its reactions with a range of haloarenes, including designed 2,6-dialkylhaloarenes, were studied in THF and in benzene. In THF, evidence supports concerted nucleophilic aromatic substitution, CSNAr, and the mechanism originally proposed by Pierre et al. is now validated through DFT studies. In benzene, besides this pathway, strong evidence for single electron transfer chemistry is reported. Experimental observations and DFT studies lead us to propose organic super electron donor generation to initiate BHAS (base-promoted homolytic aromatic substitution) cycles. Organic donor formation originates from deprotonation of benzene by KH; attack on benzene by the resulting phenylpotassium generates phenylcyclohexadienylpotassium that can undergo (i) deprotonation to form an organic super electron donor or (ii) hydride loss to afford biphenyl. Until now, BHAS reactions have been triggered by reaction of a base, MOtBu (M = K, Na), with many different types of organic additive, all containing heteroatoms (N or O or S) that enhance their acidity and place them within range of MOtBu as a base. This paper shows that with the stronger base, KH, even a hydrocarbon (benzene) can be converted into an electron-donating initiator.
Isolation and Reactivity of a Digerma Analogue of Vinyllithiums: A Lithium Digermenide
Nieder, David,Klemmer, Lukas,Kaiser, Yvonne,Huch, Volker,Scheschkewitz, David
supporting information, p. 632 - 635 (2018/03/21)
The versatile reactivity of disilenides, heavier analogues of vinyl anions, opened the door to novel heavier group 14 structure motifs with residual functionalities in the periphery around the Si=Si moiety. The corresponding germanium analogue, digermenide Tip2Ge=Ge(Tip)Li·dme2 (Tip = 2,4,6-triisopropylphenyl, dme = 1,2-dimethoxyethane), has now been obtained from the reduction of Tip2GeCl2 with 3.3 equiv of Li powder and a catalytic amount of naphthalene in dme at -70 °C. The lithium digermenide was characterized by NMR spectroscopy, UV/vis spectroscopy, X-ray diffraction, and DFT calculations. As proof of principle for its suitability for the nucleophilic transfer of the Ge=Ge motif, the reaction with chlorosilanes leads to the unsymmetrically substituted digermenes Tip2Ge=Ge(Tip)SiR3.
Nickel(I) Aryl Species: Synthesis, Properties, and Catalytic Activity
Mohadjer Beromi, Megan,Banerjee, Gourab,Brudvig, Gary W.,Hazari, Nilay,Mercado, Brandon Q.
, p. 2526 - 2533 (2018/03/13)
In this work, Ni(I) aryl species that are directly relevant to cross-coupling have been synthesized. Transmetalation of (dppf)NiIX (dppf = 1,1′-bis(diphenylphosphino)-ferrocene, X = Cl, Br) with aryl Grignard reagents or aryl boronic acids in t
Formal Nucleophilic Silyl Substitution of Aryl Halides with Silyllithium Reagents via Halogenophilic Attack of Silyl Nucleophiles
Yamamoto, Eiji,Ukigai, Satoshi,Ito, Hajime
, p. 2460 - 2464 (2017/10/06)
A new reaction has been developed for the formal nucleophilic silyl substitution of aryl halides with silyllithium or silylpotassium reagents. Dimethylphenylsilyllithium reacted with various aryl halides to form the corresponding arylsilanes in moderate to good yields with concomitant formation of the disilanes under the optimized reaction conditions. Mechanistic studies indicated that this silyl substitution reaction progresses through polar halogenophilic attack of silyl nucleophiles.
