623-40-5Relevant academic research and scientific papers
Chemoselective and Site-Selective Reductions Catalyzed by a Supramolecular Host and a Pyridine-Borane Cofactor
Morimoto, Mariko,Cao, Wendy,Bergman, Robert G.,Raymond, Kenneth N.,Toste, F. Dean
, p. 2108 - 2114 (2021/02/06)
Supramolecular catalysts emulate the mechanism of enzymes to achieve large rate accelerations and precise selectivity under mild and aqueous conditions. While significant strides have been made in the supramolecular host-promoted synthesis of small molecules, applications of this reactivity to chemoselective and site-selective modification of complex biomolecules remain virtually unexplored. We report here a supramolecular system where coencapsulation of pyridine-borane with a variety of molecules including enones, ketones, aldehydes, oximes, hydrazones, and imines effects efficient reductions under basic aqueous conditions. Upon subjecting unprotected lysine to the host-mediated reductive amination conditions, we observed excellent ?-selectivity, indicating that differential guest binding within the same molecule is possible without sacrificing reactivity. Inspired by the post-translational modification of complex biomolecules by enzymatic systems, we then applied this supramolecular reaction to the site-selective labeling of a single lysine residue in an 11-amino acid peptide chain and human insulin.
Method for synthesizing 2-pentanoneoxime through ammoxidation reaction of 2-pentanone
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Paragraph 0016-0031, (2020/04/29)
The invention discloses a method for synthesizing 2-pentanoneoxime through ammoxidation reaction of 2-pentanone,and the method comprises the following steps: reacting the 2-pentanone with hydrogen peroxide and ammonia water under the action of a catalyst to generate 2-pentanoneoxime, wherein the reaction is performed in a closed system at 40-100 DEG C for 3-6 hours to obtain the 2-pentanoneoxime,andthe catalyst is a fluorine modified titanium silicalite molecular sieve; and after the reaction is finished, filtering the reaction solution to recover the catalyst, separating the solution to obtain an organic layer, drying with anhydrous sodium sulfate, and carrying out reduced pressure distillation to obtain the pure 2-pentanoneoxime. Compared with a conventional method for synthesizing the2-pentanoneoxime by an ammonia oxidation method catalyzed by a titanium silicalite molecular sieve in the prior art, the method disclosed by the invention has the advantages of high reaction product yield, low energy consumption in the reaction process, simple process method and the like.
Copper-Catalyzed Annulation of Oxime Acetates with α-Amino Acid Ester Derivatives: Synthesis of 3-Sulfonamido/Imino 4-Pyrrolin-2-ones
Miao, Chun-Bao,Zheng, An-Qi,Zhou, Li-Jin,Lyu, Xinyu,Yang, Hai-Tao
supporting information, p. 3381 - 3385 (2020/04/21)
A copper-catalyzed annulation of oxime acetates and α-amino acid ester derivatives for the easy preparation of 4-pyrrolin-2-ones bearing a 3-amino group has been developed. This process features the oxidation of amines with oxime esters as the internal oxidant to produce the active 1,3-dinucleophilic and 1,2-dielectrophilic species concurrently. The subsequent nucleophilic cyclization realizes the efficient construction of 4-pyrrolin-2-one derivatives.
High-Throughput Screening of the Alkoxide/Oxime-Based Library: An Alternative to Organotin Compounds for the Alkoxysilane Condensation in Adhesives and Sealants
Colin, Boris,Lavastre, Olivier,Fouquay, Stéphane,Michaud, Guillaume,Simon, Frédéric,Brusson, Jean-Michel
supporting information, p. 300 - 309 (2019/02/19)
In this work, a high-throughput screening (HTS) method was used to discover new efficient catalysts to substitute organotin compounds (DBTDL) for the cross-linking of silyl-modified polymers (SMPs). We report here on the use of our HTS method to investigate a library of alkoxide/oxime systems with different metal/ligand (M/L) ratios. Among the 156 candidates tested, 40 interesting hits were detected. Then, the cross-linking times for the better hits were measured on the SMP. Some of these seem to be more efficient than DBTDL and exhibit a good stability during storage in cartridges. Thereby, a high efficiency of alkoxide/oxime systems was established that shows great potential for the generation of new ligands to provide new tin-free catalysts for the cross-linking of adhesives and sealants.
Copper-catalyzed synthesis of thiazol-2-yl ethers from oxime acetates and xanthates under redox-neutral conditions
Zhu, Zhongzhi,Tang, Xiaodong,Cen, Jinghe,Li, Jianxiao,Wu, Wanqing,Jiang, Huanfeng
supporting information, p. 3767 - 3770 (2018/04/17)
A novel copper-catalyzed annulation of oxime acetates and xanthates for the synthesis of thiazol-2-yl ethers with remarkable regioselectivity has been developed. Various oxime acetates, whether derived from aryl ketones or alkyl ketones, or natural product cores are suitable for this conversion. Unique dihydrothiazoles were also obtained when both reaction sites were methine. Mechanistic studies indicated that imino copper(iii) intermediates were involved. In addition, this protocol proceeded under redox-neutral conditions and did not require additives or ligands.
Iminyl Radical-Mediated Controlled Hydroxyalkylation of Remote C(sp3)-H Bond via Tandem 1,5-HAT and Difunctionalization of Aryl Alkenes
Ma, Zhi-Yong,Guo, Li-Na,Gu, Yu-Rui,Chen, Li,Duan, Xin-Hua
supporting information, p. 4341 - 4347 (2018/10/20)
A visible-light mediated γ-hydroxyalkylation of ketones via C(sp3)-H functionalization has been developed under redox neutral conditions. This protocol relies on the iminyl radical-triggered 1,5-HAT followed by oxyalkylation of alkenes, wherein C?C and C?O bonds were constructed in one step. This three-component reaction features mild conditions, wide substrate scope and excellent functional group tolerance, thus providing a facile and highly efficient access to complex valuable ketones. (Figure presented.).
A process for synthesizing of cyclohexanone oxime (by machine translation)
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Paragraph 0037; 0038, (2017/08/29)
The invention discloses a process for synthesizing of cyclohexanone oxime, in carbonate aqueous solution is in the system, in order to titanium-silicon molecular sieve as the catalyst, ketone, ammonia and hydrogen peroxide produced by the reaction of oxime; and, in the reaction process through the pH value of the reaction system to determine the real-time monitoring of the reaction process and to determine the optimal reaction mixture ratio. By monitoring the reaction system pH value to judge in the reaction process to determine the optimal reaction ratio, further through the carbonate aqueous solution to adjust the pH value of the system in order to improve the reaction speed and ammonia conversion rate. (by machine translation)
Synthesis of ketoximes via a solvent-assisted and robust mechanochemical pathway
Aakeroey, Christer B.,Sinha, Abhijeet S.
, p. 8168 - 8171 (2013/09/02)
A versatile and robust mechanochemical route to ketone-oxime conversions has been established for a broad range of ketones via a simple mortar-pestle grinding method. The relative reactivity of aldehydes vs. ketones under these conditions has also been explored, along with an examination of the possible connection between reactivity and electronic substituent effects.
Selective ammoximation of ketones and aldehydes catalyzed by a trivanadium-substituted polyoxometalate with H2O2 and ammonia
Xue, Xiaoling,Song, Fangyuan,Ma, Baochun,Yu, Yongze,Li, Cheng,Ding, Yong
, p. 61 - 65 (2013/05/09)
The ammoximation of different ketones and aldehydes to their corresponding oximes catalyzed by K6[PW9 V3O 40]·4H2O was carried out with hydrogen peroxide and ammonia in isopropanol at room temperature. High yields of oximes were obtained in this catalytic system. This catalytic system was proved to be heterogeneous by the ammoximation activity of removal of catalyst and the elemental analysis of the filtrate after reaction. A possible procedure for the ammoximation catalyzed by K6[PW9V3O40] ·4H2O with H2O2 and NH 3·H2O was proposed. The fresh and used catalysts were characterized by IR and 31P MAS NMR, which revealed the good stability of the catalyst.
