5554-54-1Relevant academic research and scientific papers
Green synthesis method of 1,2,2,6,6-pentamethyl-4-piperidone
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Paragraph 0023, (2020/05/30)
The invention discloses a green synthesis method of 1,2,2,6,6-pentamethyl-4-piperidone. 2,2,6,6-tetramethylpiperidone and DMC which serve as raw materials are stirred and reacted at a certain temperature for a certain time under the actions of a solvent and a catalyst, cooling, filtering, concentrating and negative pressure rectification are carried out after the reaction is finished in order to obtain the final product 1,2,2,6,6-pentamethyl-4-piperidone, and yield can reach 90%. Toxic and harmful dimethyl sulfate, chloroform, methyl iodide, formaldehyde, formic acid and the like are not usedin the whole synthesis process, no wastewater is discharged in the production process, and the method is a green synthesis mode of 1,2,2,6,6-pentamethyl-4-piperidone.
Preparation method of 1, 2, 2, 6, 6-pentamethyl-4-piperidone
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Paragraph 0025-0032, (2020/04/17)
The invention discloses a preparation method of 1, 2, 2, 6, 6-pentamethyl-4-piperidone. The preparation method comprising following steps: taking 2, 2, 6, 6-tetramethylpiperidone as a raw material; inthe presence of an alkaline substance and in a solvent, stirring at a certain temperature and dropwise adding a certain amount of dimethyl sulfate for reaction, reacting for a certain period of timeafter the dropwise addition is finished, after the reaction is finished, cooling, filtering, concentrating and rectifying to obtain the final product 1, 2, 2, 6, 6-pentamethyl-4-piperidone. The yieldof the product can reach 95% or above, the yield is greatly increased, the cost is reduced, and the practical significance of industrialization can be achieved.
Platinum-(phosphinito-phosphinous acid) complexes as bi-talented catalysts for oxidative fragmentation of piperidinols: An entry to primary amines
Membrat, Romain,Vasseur, Alexandre,Moraleda, Delphine,Michaud-Chevallier, Sabine,Martinez, Alexandre,Giordano, Laurent,Nuel, Didier
, p. 37825 - 37829 (2019/12/03)
Platinum-(phosphinito-phosphinous acid) complex catalyzes the oxidative fragmentation of hindered piperidinols according to a hydrogen transfer induced methodology. This catalyst acts successively as both a hydrogen carrier and soft Lewis acid in a one pot-two steps process. This method can be applied to the synthesis of a wide variety of primary amines in a pure form by a simple acid-base extraction without further purification.
Bi-radical compound composed of triaryl methyl radical and nitroxide radical and salt thereof and preparation method and application of bi-radical compound composed of triaryl methyl radical and nitroxide radical and salt thereof
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Paragraph 0012; 0116; 0117; 0118, (2018/12/02)
The invention provides a bi-radical compound composed of a triaryl methyl radical and a nitroxide radical and salt thereof and a preparation method and application of the bi-radical compound composedof the triaryl methyl radical and the nitroxide radical and the salt thereof. A structural formula of the bi-radical compound is as shown in the formula 1; the formula is shown in the description; thepreparation method comprises the steps that a compound A1 and a compound A2 are subjected to acid amide condensation reaction to obtain a compound A3; the compound A3 and a compound A4 are subjectedto acid amide condensation reaction to obtain the bi-radical compound and the salt thereof. The portion, provided with both the nitroxide radical and the triaryl methyl radical, of a bi-radical polarization agent has the following advantages that the frequency matching ability is better, and the CE efficiency is higher; under a magic angle spinning condition, a depolarization effect does not exist, and a high field DNP enhancing effect is better; exchange interaction is stronger; the water solubility is good, so that the DNP enhancing multiple is high; by modifying R1, R2, R3, R4, R5 and R6 groups, exchange interaction can be improved moderately, bi-radical relaxation time can be prolonged moderately, and the bi-radical water solubility can be improved moderately, so that the DNP propertyof the polarization agent is improved.
Phosphinous Acid Platinum Complex as Robust Catalyst for Oxidation: Comparison with Palladium and Mechanistic Investigations
Membrat, Romain,Vasseur, Alexandre,Martinez, Alexandre,Giordano, Laurent,Nuel, Didier
supporting information, p. 5427 - 5434 (2018/10/20)
Secondary phosphine oxides proved to be effective preligands to stabilise a hydroxy-platinum based catalyst that allows the aerobic/anaerobic oxidation of challenging substrates. Kinetic comparisons showed that this system is more efficient and stable than previously reported similar palladium-based catalysts. A neutral platinum dimer bearing bridging hydroxy ligands has been isolated and fully characterised by X-ray diffraction and its involvement in the mechanism has been evidenced by mechanistic studies.
Synthesis method of 1,2,2,6,6-pentamethyl-4-piperidone
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Paragraph 0028; 0029; 0030; 0031; 0032; 0033; 0034-0067, (2018/03/26)
The invention provides a synthesis method of 1,2,2,6,6-pentamethyl-4-piperidone. The synthesis method comprises the following steps: adding acetone and methylamine into a reaction kettle according toa proportion; then adding a catalyst, and stirring for carrying out reaction, wherein the catalyst is prepared from sulfonic acid functionalized SBA-15; after the reaction is finished, adding an alkali quenching catalyst, and then filtering out the catalyst to obtain a crude product of the 1,2,2,6,6-pentamethyl-4-piperidone; purifying the obtained crude product to obtain the pure 1,2,2,6,6-pentamethyl-4-piperidone product. The synthesis method, provided by the invention, of the1,2,2,6,6-pentamethyl-4-piperidone is high in product yield, economical, efficient and environmentally friendly, thusbeing very suitable for industrial production.
Synthesis of a Sterically Demanding Dispiropiperidine and Its Application in Monoamidodialkyl Zincate Complexes
Morisako, Shogo,Shang, Rong,Yamamoto, Yohsuke
supporting information, p. 10767 - 10773 (2016/10/26)
The new sterically hindered piperidine analog, dispiro[cyclohexane-2,2′-piperidine-6′,2″-cyclohexane] (CPC(H), 2), and its N-methylated derivative CPC(Me) (3) were synthesized from commercially available starting materials in short steps. The N-lithiated amide LiCPC (4) was also isolated from 2 as a cyclictrimer in single crystals and showed slightly larger steric hindrance than that of lithium 2,2,6,6-tetramethylpiperidide (LiTMP) in the competitive methylation reaction with methyl trifluoromethanesulfonate. In addition, the heterobimetallic heteroleptic zincate complexes [Li(μ-NR2)(μ-Et)Zn(Et)] (NR2 = CPC, 5, and NR2 = TMP, 6) were obtained as THF- and TMEDA-coordinated monomer 5·(THF)2, 6·(THF)2, 5·TMEDA, and 6·TMEDA (THF = tetrahydrofuran, TMEDA = N,N,N′,N′-tetramethylethylenediamine). These molecular structures bearing different amido ligands in single crystals showed little structural differences from crystallographic studies. Diffusion-ordered spectroscopy (DOSY) revealed that the solution structures of the zincate complexes 5·(THF)2 and 6·(THF)2 only differ in the number of coordination THF molecules. In the deprotonation reactions with tert-butyl 3-bromobenzoate, the zincate complexes containing the CPC ligand [Li(μ-CPC)(μ-R)Zn(R)] (R = Et (5), tBu) showed moderately improved regioselectivity for the 6 position in comparison to those containing the TMP ligand [Li(μ-TMP)(μ-R)Zn(R)] (R = Et (6), tBu).
Synthesis of triacetonamine N-alkyl derivatives reinvestigated
Banert, Klaus,Fink, Katharina,Hagedorn, Manfred,Richter, Frank
, p. 379 - 390 (2013/09/24)
The N-alkylated 2,2,6,6-tetramethylpiperidin-4-ones 3c-f were prepared from the acetal 6a of triacetonamine (3a) by alkylation followed by hydrolysis of the acetal functionality or alternatively from the corresponding secondary alcohol 2,2,6,6-tetramethyl
A slowly relaxing rigid biradical for efficient dynamic nuclear polarization surface-enhanced NMR spectroscopy: Expeditious characterization of functional group manipulation in hybrid materials
Zagdoun, Alexandre,Casano, Gilles,Ouari, Olivier,Lapadula, Giuseppe,Rossini, Aaron J.,Lelli, Moreno,Baffert, Mathieu,Gajan, David,Veyre, Laurent,Maas, Werner E.,Rosay, Melanie,Weber, Ralph T.,Thieuleux, Chloe,Coperet, Christophe,Lesage, Anne,Tordo, Paul,Emsley, Lyndon
supporting information; scheme or table, p. 2284 - 2291 (2012/03/10)
A new nitroxide-based biradical having a long electron spin-lattice relaxation time (T1e) has been developed as an exogenous polarization source for DNP solid-state NMR experiments. The performance of this new biradical is demonstrated on hybrid silica-based mesostructured materials impregnated with 1,1,2,2-tetrachloroethane radical containing solutions, as well as in frozen bulk solutions, yielding DNP enhancement factors (∈) of over 100 at a magnetic field of 9.4 T and sample temperatures of ~100 K. The effects of radical concentration on the DNP enhancement factors and on the overall sensitivity enhancements (σ?) are reported. The relatively high DNP efficiency of the biradical is attributed to an increased T1e, which enables more effective saturation of the electron resonance. This new biradical is shown to outperform the polarizing agents used so far in DNP surface-enhanced NMR spectroscopy of materials, yielding a 113-fold increase in overall sensitivity for silicon-29 CPMAS spectra as compared to conventional NMR experiments at room temperature. This results in a reduction in experimental times by a factor >12 700, making the acquisition of 13C and 15N one- and two-dimensional NMR spectra at natural isotopic abundance rapid (hours). It has been used here to monitor a series of chemical reactions carried out on the surface functionalities of a hybrid organic-silica material.
Synthesis and reduction kinetics of sterically shielded pyrrolidine nitroxides
Paletta, Joseph T.,Pink, Maren,Foley, Bridget,Rajca, Suchada,Rajca, Andrzej
supporting information, p. 5322 - 5325 (2013/01/15)
A series of sterically shielded pyrrolidine nitroxides were synthesized, and their reduction by ascorbate (vitamin C) indicate that nitroxide 3, a tetraethyl derivative of 3-carboxy-PROXYL, is reduced at the slowest rate among known nitroxides, i.e., at a 60-fold slower rate than that for 3-carboxy-PROXYL.
