776-35-2Relevant academic research and scientific papers
SYNTHESIS OF 5,7-DIHYDRODIBENZOMETALLEPINS VIA A NEW DI-GRIGNARD OR DILITHIUM REAGENT
Leung, Wing-Por,Raston, Colin L.
, p. C1 - C4 (1982)
Thermally robust metallacycles (L=2-, M=Ti, Zr, Hf) and have been obtained from the newly developed reagents, L2 and L2, as has the silylated derivative, 2.A new radical anion of 9,10-dihydrophenanthrene derived from the reaction of lithium and LCl2 or LBr2 in thf has been detected.
ELECTRO-ORGANIC REACTIONS. PART 29: CATHODIC REDUCTION ACTIVATED BY ARENE-CHROMIUM TRICARBONYL COMLEXATION
Chiu, Y. Lin,Sant'ana, Antonio E. G.,Utley, James H. P.
, p. 1349 - 1352 (1987)
Chromium tricarbonyl-arene complexes are easily reduced electrochemically and reduction potentials ca. 0.6 V less than the corresponding arenes; hence stilbene is activated towards hydrodimerisation and phenanthrene towards hydrogenation
Aromatic compound hydrogenation and hydrodeoxygenation method and application thereof
-
Paragraph 0094-0095; 0106-0113, (2021/05/29)
The invention belongs to the technical field of medicines, and discloses an aromatic compound hydrogenation and hydrodeoxygenation method under mild conditions and application of the method in hydrogenation and hydrodeoxygenation reactions of the aromatic compounds and related mixtures. Specifically, the method comprises the following steps: contacting the aromatic compound or a mixture containing the aromatic compound with a catalyst and hydrogen with proper pressure in a solvent under a proper temperature condition, and reacting the hydrogen, the solvent and the aromatic compound under the action of the catalyst to obtain a corresponding hydrogenation product or/and a hydrodeoxygenation product without an oxygen-containing substituent group. The invention also discloses specific implementation conditions of the method and an aromatic compound structure type applicable to the method. The hydrogenation and hydrodeoxygenation reaction method used in the invention has the advantages of mild reaction conditions, high hydrodeoxygenation efficiency, wide substrate applicability, convenient post-treatment, and good laboratory and industrial application prospects.
A facile and versatile electro-reductive system for hydrodefunctionalization under ambient conditions
Huang, Binbin,Guo, Lin,Xia, Wujiong
supporting information, p. 2095 - 2103 (2021/03/26)
A general electrochemical system for reductive hydrodefunctionalization is described, employing the inexpensive and easily available triethylamine (Et3N) as a sacrificial reductant. This protocol is characterized by facile operation, sustainable conditions, and exceptionally wide substrate scope covering the cleavage of C-halogen, N-S, N-C, O-S, O-C, C-C and C-N bonds. Notably, the selectivity and capability of reduction can be conveniently switched by simple incorporation or removal of an alcohol as a co-solvent.
On the multifaceted roles of NiSx in hydrodearomatization reactions catalyzed by unsupported Ni-promoted MoS2
Ji, Yinjie,Lercher, Johannes A.,Shi, Hui,Vogelgsang, Ferdinand
, p. 212 - 223 (2020/09/16)
A series of unsupported Ni-Mo sulfide catalysts with varying Ni contents (0.13–0.72 molNi molNi+Mo-1) was post-synthetically treated with concentrated HCl to remove large crystallites of accessible NiSx. These sulfide particles inevitably form and grow at Ni concentrations required for the synthesis, but generally have very low activities. In all cases, Ni concentrations were greatly reduced by the HCl treatment. While this ‘leaching’ strategy successfully improved the reaction rates of high Ni-content (>0.4 molNi molmetal-1) catalysts for the hydrogenation of phenanthrene, modest to drastic decreases in catalytic rates (×0.1–0.8) were registered for catalysts with lower Ni concentrations. For the lowest Ni-loaded catalyst (0.05 molNi molmetal-1), HCl treatment caused a dramatic loss of specific surface area and catalytic activity by more than a factor of 6 and shifted the selectivity pattern to that of pure MoS2. These observations allow us to conclude that Ni atoms incorporated at the slab edges are inherently susceptible to HCl attack. NiSx, however, are the preferential sites at which HCl induces dissolution. Experiments with inter-particle mixtures and segregated beds of NiSx and MoS2 demonstrate that NiSx not only activates H2, but also acts as a reservoir to dynamically incorporate Ni in the MoS2 slabs at reaction conditions. These beneficial effects are reduced, as nickel sulfide particles become excessively abundant as typical for high Ni-content catalysts, for which edge substitution by Ni is near or at its maximum. The areal activity and concentration of chemisorbed nitric oxide (NO) are well correlated for the leached catalysts, with the exception of the lowest Ni-containing catalyst that has a low degree of Ni edge substitution (20% of total edge atoms) and predominantly unpromoted sites. This linear correlation shows that the Ni-promoted sites are more than five-fold as active as the unpromoted sites.
Highly Active Superbulky Alkaline Earth Metal Amide Catalysts for Hydrogenation of Challenging Alkenes and Aromatic Rings
Eyselein, Jonathan,F?rber, Christian,Grams, Samuel,Harder, Sjoerd,Knüpfer, Christian,Langer, Jens,Martin, Johannes,Thum, Katharina,Wiesinger, Michael
supporting information, p. 9102 - 9112 (2020/03/30)
Two series of bulky alkaline earth (Ae) metal amide complexes have been prepared: Ae[N(TRIP)2]2 (1-Ae) and Ae[N(TRIP)(DIPP)]2 (2-Ae) (Ae=Mg, Ca, Sr, Ba; TRIP=SiiPr3, DIPP=2,6-diisopropylphenyl). While monomeric 1-Ca was already known, the new complexes have been structurally characterized. Monomers 1-Ae are highly linear while the monomers 2-Ae are slightly bent. The bulkier amide complexes 1-Ae are by far the most active catalysts in alkene hydrogenation with activities increasing from Mg to Ba. Catalyst 1-Ba can reduce internal alkenes like cyclohexene or 3-hexene and highly challenging substrates like 1-Me-cyclohexene or tetraphenylethylene. It is also active in arene hydrogenation reducing anthracene and naphthalene (even when substituted with an alkyl) as well as biphenyl. Benzene could be reduced to cyclohexane but full conversion was not reached. The first step in catalytic hydrogenation is formation of an (amide)AeH species, which can form larger aggregates. Increasing the bulk of the amide ligand decreases aggregate size but it is unclear what the true catalyst(s) is (are). DFT calculations suggest that amide bulk also has a noticeable influence on the thermodynamics for formation of the (amide)AeH species. Complex 1-Ba is currently the most powerful Ae metal hydrogenation catalyst. Due to tremendously increased activities in comparison to those of previously reported catalysts, the substrate scope in hydrogenation catalysis could be extended to challenging multi-substituted unactivated alkenes and even to arenes among which benzene.
Birch-Type Photoreduction of Arenes and Heteroarenes by Sensitized Electron Transfer
Chatterjee, Anamitra,K?nig, Burkhard
supporting information, p. 14289 - 14294 (2019/08/30)
The direct reduction of arenes and heteroarenes by visible-light irradiation remains challenging, as the energy of a single photon is not sufficient for breaking aromatic stabilization. Shown herein is that the energy accumulation of two visible-light photons allows the dearomatization of arenes and heteroarenes. Mechanistic investigations confirm that the combination of energy-transfer and electron-transfer processes generates an arene radical anion, which is subsequently trapped by hydrogen-atom transfer and finally protonated to form the dearomatized product. The photoreduction converts planar aromatic feedstock compounds into molecular skeletons that are of use in organic synthesis.
Experimental and Theoretical Studies on the Aqueous Solvation and Reactivity of SmCl2 and Comparison with SmBr2 and SmI2
Ramírez-Solís, Alejandro,Bartulovich, Caroline O.,León-Pimentel, César Iván,Saint-Martin, Humberto,Anderson, William R.,Flowers, Robert A.
supporting information, p. 13927 - 13932 (2019/10/16)
Water addition to Sm(II) has been shown to increase reactivity for both SmI2 and SmBr2. Previous work in our groups has demonstrated that this increase in reactivity can be attributed to coordination induced bond weakening enabling substrate reduction through proton-coupled electron transfer. The present work examines the interaction of water with samarium dichloride (SmCl2) and illustrates the importance of the Sm-X interaction and bond distance upon water addition critical for the reactivity of the reagent system. Born-Oppenheimer molecular dynamics simulations identify substantial variations among the reductants created in solution upon water addition to SmI2, SmBr2, and SmCl2 with the latter showing the least halide dissociation. This results in a lower water coordination number for SmCl2, creating a more powerful reducing system. As previously shown with the other SmX2-water systems, coordination-induced bond-weakening of the O-H bond of water bound to Sm(II) results in significant bond weakening. In the case of SmCl2, the bond weakening is estimated to be in the range of 83 to 88.5 kcal/mol.
Aerobic and Ligand-Free Manganese-Catalyzed Homocoupling of Arenes or Aryl Halides via in Situ Formation of Aryllithiums
Liu, Yujia,Bergès, Julien,Zaid, Yassir,Chahdi, Fouad Ouazzani,Van Der Lee, Arie,Harakat, Dominique,Clot, Eric,Jaroschik, Florian,Taillefer, Marc
, p. 4413 - 4420 (2019/03/26)
Ligand-free manganese-catalyzed homocoupling of arenes or aryl halides can be carried out under aerobic conditions via the in situ formation of the corresponding aryllithiums. A wide range of biaryls and derivatives has been obtained, and a mechanism involving monomeric manganese-oxo complexes has been proposed on the basis of DFT calculations.
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.
