2037-26-5Relevant academic research and scientific papers
Synthetic method of toluene-d8
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Paragraph 0027-0030, (2020/08/02)
The invention relates to a synthetic method of toluene-d8, and belongs to a synthetic technology of deuterated compounds. The preparation method comprises the following steps: slowly adding penta-halogenated toluene into a solvent to prepare a clear solution A; transferring the solution A into an autoclave, slowly adding a deuterated reagent into the solution obtained in the step 1 under the protection of nitrogen, adding a catalyst B to obtain a mixed solution C, performing filtering, and dropwise adding deionized water to obtain a filtrate D; and adding heavy water, a catalyst F and zeoliteafter fractionation, finally fractionating the solution, and collecting a fraction at 110 DEG C to obtain toluene-d8. According to the method, halogen deuterium exchange reaction on a benzene ring andhydrogen deuterium exchange reaction on methyl are carried out step by step, so that complete deuteration reaction is facilitated, and the deuteration rate of the obtained product is high; and the use of the catalyst reduces the use amount of a deuterated reagent, reduces the production cost, and can effectively break the dependence of the domestic market on import.
Iridium Hydride Complexes with Cyclohexyl-Based Pincer Ligands: Fluxionality and Deuterium Exchange
Polukeev, Alexey V.,Marcos, Rocío,Ahlquist, M?rten S. G.,Wendt, Ola F.
, p. 2600 - 2608 (2016/09/04)
Two hydride compounds with aliphatic pincer ligands, (PCyP)IrH2 (PCyP = {cis-1,3-bis[(di-tert-butylphosphino)methyl]cyclohexane}- (1) and (PCyP)IrH4 (2), have been studied, with emphasis on features where such systems differ from arene-based analogues. Both compounds reveal relatively rapid exchange between α-C-H and Ir-H, which can occur via formation of carbene or through demetalation, with nearly equal barriers. This observation is confirmed by deuterium incorporation into the α-C-H position. Complex 1 can reversibly add an N2 molecule, which competes with the α-agostic bond for a coordination site at iridium. The hydrogen binding mode in tetrahydride 2 is discussed on the basis of NMR and IR spectra, as well as DFT calculations. While the interpretation of the data is somewhat ambiguous, the best model seems to be a tetrahydride with minor contribution from a dihydrido-dihydrogen complex. In addition, the catalytic activity of 1 in deuterium exchange using benzene-d6 as a deuterium source is presented.
Synthesis and chemistry of bis(triisopropylphosphine) nickel(i) and nickel(0) precursors
Beck, Robert,Shoshani, Manar,Krasinkiewicz, Jonathan,Hatnean, Jillian A.,Johnson, Samuel A.
, p. 1461 - 1475 (2013/03/13)
High yield syntheses of (iPr3P)2NiX (3a-c), (where X = Cl, Br, I) were established by comproportionation of ( iPr3P)2NiX2 (1a-c) with ( iPr3P)2Ni(η2-C2H 4) (2). Reaction of 1a with either NaH or LiHBEt3 provided (iPr3P)2NiHCl (4), along with 3a as a side-product. Reduction of (iPr3P)2NiCl (3a-c) with Mg in presence of nitrogen saturated THF solutions provided the dinitrogen complex [(iPr3P)2Ni]2(μ- η1:η1-N2) (5). In aromatic solvents such as benzene and toluene a thermal equilibrium exists between 5 and the previously reported monophosphine solvent adducts (iPr 3P)Ni(η6-arene) (6a,b). Reaction of 5 with carbon dioxide provided (iPr3P)2Ni(η2- CO2) (7). Thermolysis of 9 at 60 °C provided a mixture of products that included the reduction product (iPr3P) 2Ni(CO)2 (8) along with iPr3PO, as identified by NMR spectroscopy. Complex 8 was also prepared in high yield from the reaction of 5 with CO. Reaction of 5 with CS2 gave the dimeric carbon disulfide complex [(iPr3P)Ni(μ- η1:η2-CS2)]2 (9). Diphenylphosphine reacts with 5 to form the dinuclear Ni(i) complex [( iPr3P)Ni(μ2-PPh2)]2 (10). Complex 5 reacts with PhSH to form (iPr3P) 2Ni(SPh)(H) (11), which slowly loses H2 and iPr3P to form the dimeric Ni(i) complex [( iPr3P)Ni(μ2-SPh)]2 (12) at room temperature. Complex 12 was also accessed by salt metathesis from the reaction of (iPr3P)2NiCl (3a) with PhSLi, which demonstrates the utility of 3a as a Ni(i) precursor. With the exception of 6a,b, all compounds were structurally characterized by single-crystal X-ray crystallography. The Royal Society of Chemistry 2013.
An Air/water-stable tridentate N-heterocyclic carbene-palladium(II) Complex: Catalytic C-H activation of hydrocarbons via hydrogen/deuterium exchange process in deuterium oxide
Lee, Joo Ho,Yoo, Kyung Soo,Park, Chan Pil,Olsen, Janet M.,Sakaguchi, Satoshi,Prakash, G. K. Surya,Mathew, Thomas,Jung, Kyung Woon
experimental part, p. 563 - 568 (2009/11/30)
While developing novel catalysts for carbon-carbon or carbon-heteroatom coupling (nitrogen, oxygen, or fluorine), we were able to introduce tridentate N-heterocyclic carbene (NHC)-amidate-alkoxide palladium(II) complexes. In aqueous solution, these NHC-Pd(II) complexes showed high ability for C-H activation of various hydrocarbons (cyclohexane, cyclopentane, dimethyl ether, tetrahydrofuran, acetone, and toluene) under mild conditions.
An N.M.R. Study of Electron Donor-Electron Acceptor Interaction Between Aromatic Hydrocarbons and Diazines
Hurst, Derek T.,Thakrar, Usha B.,Wells, Clifford H. J.,Wyer, John
, p. 1313 - 1319 (2007/10/02)
Equilibrium constants have been measured by n.m.r. spectroscopy for the electron donor-electron acceptor interaction between a number of aromatic hydrocarbons and diazines.The values obtained have shown that the interaction is weak, and that the aromatic hydrocarbon acts as the electron donor and the diazine as the electron acceptor in the systems studied.Chemical-shift data have provided evidence for the relative positioning of the donor and acceptor components within the various complexes.The effect of temperature on the equilibrium constant for complex formation between (2H6)benzene and pyrazine has shown that the enthalpy of format ion is close to zero.
