363-02-0Relevant articles and documents
Rhodium(iii)-catalyzed asymmetric [4+1] spiroannulations of: O -pivaloyl oximes with α-diazo compounds
Chang, Junbiao,Deng, Wei-Qiao,Kong, Lingheng,Li, Xingwei,Liu, Bingxian,Sun, Lincong,Wang, Fen,Zhao, Yanlian
supporting information, p. 8268 - 8271 (2021/08/25)
Chiral RhIII catalysts can catalyze the asymmetric [4+1] spiroannulation of O-pivaloyl oximes with α-diazo homophthalimides under redox-neutral and acid/base-neutral conditions, leading to formation of chiral spirocyclic imines as a result of C-H activation and N-O cleavage. The reaction proceeded with high efficiency and features broad substrate scope, mild reaction conditions, and high to excellent enantioselectivities. This journal is
Access to Cyanoimines Enabled by Dual Photoredox/Copper-Catalyzed Cyanation of O-Acyl Oximes
Wei, Ziyan,Yu, Shouyun,Zhang, Ai Hua,Zhang, Hao
supporting information, p. 7315 - 7320 (2020/10/02)
An efficient strategy for the synthesis of pharmaceutically important and synthetically useful cyanoimines, as well as cyanamides, has been described. This strategy is enabled by dual photoredox/copper-catalyzed cyanation of O-acyl oximes or O-acyl hydroxamides. This state of the art protocol for cyanoimines and cyanamides features readily available starting materials, mild reaction conditions, good functional group tolerance, and operational simplicity. The resultant cyanoimines can be transformed into structurally diverse and functionally important N-containing heterocycles.
Microdroplets as Microreactors for Fast Synthesis of Ketoximes and Amides
Zhang, Wenwen,Yang, Shiwei,Lin, Qiuyu,Cheng, Heyong,Liu, Jinhua
, p. 851 - 859 (2019/01/24)
The formation of amide bonds is one of the most valuable transformations in organic synthesis. Beckmann rearrangement is a well-known method for producing secondary amides from ketoximes. This study demonstrates the rapid synthesis of ketoximes and amides in microdroplets. Many factors are found to affect the yield, such as microdroplet generation devices, temperature, catalysts, and concentrations of reactants. In particular, the temperature has a great influence on the synthesis of amide, which is demonstrated by a sharp ascendance to the yield when the temperature was increased to 45 °C. The best amide yield (93.3%) can be obtained by using coaxial flowing devices, a sulfonyl chloride compound as a catalyst, and heating to 55 °C in microdroplets. The yields can reach 78.7-91.3% for benzoylaniline and 87.2-93.4% for benzophenone oximes in several seconds in microdroplets compared to 10.1-66.1% and 82.5-93.3% in several hours in the bulk phase. Apart from the dramatically decreased reaction time and enhanced reaction yields, the microdroplet synthesis is also free of severe reaction environments (anhydrous and anaerobic conditions). In addition, the synthesis in microdroplets also saves reactants and solvents and reduces the waste amounts. All of these merits indicate that the microdroplet synthesis is a high-efficiency green methodology.
Vilsmeier-Haack reagent mediated synthetic transformations with an immobilized iridium complex photoredox catalyst
Zhi, Peng,Xi, Zi-Wei,Wang, Dan-Yan,Wang, Wei,Liang, Xue-Zheng,Tao, Fei-Fei,Shen, Run-Pu,Shen, Yong-Miao
supporting information, p. 709 - 717 (2019/01/10)
An immobilized iridium complex photocatalyst Ir(ppy)2(PDVB-py) was synthesized by immobilization of the iridium complex onto the nanoporous vinylpyridine-divinylbenzene copolymer (PDVB-py). Its application for the synthesis of amides, nitriles, and anhydrides was reported via reactions under the action of the visible-light-driven in situ generated Vilsmeier-Haack reagent from CBr4 in DMF. The results showed that this heterogeneous photocatalyst has extremely high activity and excellent stability to be recycled five times.
o-Phthalic Anhydride/Zn(OTf)2 co-catalyzed Beckmann rearrangement under mild conditions
Xu, Ze-Feng,Zhang, Teng,Hong, Wenjun
supporting information, p. 3113 - 3117 (2019/05/08)
o-Phthalic anhydride/Zn(OTf)2 co-catalyzed Beckmann rearrangement was developed, producing the corresponding amide in up to 99% yield with acid-sensitive functionalities tolerated well, and the scale of the reaction could be enlarged to 77 mmol and the excellent yield was maintained. A successive procedure was developed. Moreover, the reaction was carried out at rt under nearly neutral conditions, and the workup was concise. These features illustrated the potential of the protocol in amide synthesis.
Visible-Light-Photosensitized Aryl and Alkyl Decarboxylative Functionalization Reactions
Patra, Tuhin,Mukherjee, Satobhisha,Ma, Jiajia,Strieth-Kalthoff, Felix,Glorius, Frank
supporting information, p. 10514 - 10520 (2019/07/12)
Despite significant progress in aliphatic decarboxylation, an efficient and general protocol for radical aromatic decarboxylation has lagged far behind. Herein, we describe a general strategy for rapid access to both aryl and alkyl radicals by photosensitized decarboxylation of the corresponding carboxylic acids esters followed by their successive use in divergent carbon–heteroatom and carbon–carbon bond-forming reactions. Identification of a suitable activator for carboxylic acids is the key to bypass a competing single-electron-transfer mechanism and “switch on” an energy-transfer-mediated homolysis of unsymmetrical σ-bonds for a concerted fragmentation/decarboxylation process.
Preparation method of ketoxime
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Paragraph 0038-0040, (2018/07/30)
The invention belongs to the technical field of ketoxime and specifically relates to a preparation method of ketoxime. The preparation method comprises the following steps: (1) sufficiently mixing ketone and hydroxylamine hydrochloride, adding absolute ethyl alcohol, and stirring till total dissolution to obtain mixed liquid 1; (2) adding imidazolyl anion functionalized ionic liquid into the mixedliquid 1, and heating till ethanol reflux, wherein reaction liquid is obtained after the reaction; (3) removing ethanol in the reaction liquid, adding deionized water and stirring to separate out solid, and performing suction filtration and washing to obtain white solid ketoxime. According to the preparation method provided by the invention, by taking the imidazolyl anion functionalized ionic liquid as a catalyst, a reaction between ketone and hydroxylamine hydrochloride can be efficiently catalyzed, and the preparation method has the advantages of mild reaction conditions, high product yieldand purity and the like.
Beckmann rearrangement of ketoxime catalyzed by N-methyl-imidazolium hydrosulfate
Hu, Hongyu,Cai, Xuting,Xu, Zhuying,Yan, Xiaoyang,Zhao, Shengxian
, (2018/08/21)
Beckmann rearrangement of ketoxime catalyzed by acidic ionic liquid-N-methyl-imidazolium hydrosulfate was studied. Rearrangement of benzophenone oxime gave the desirable product with 45% yield at 90 ?C. When co-catalyst P2O5 was added, the yield could be improved to 91%. The catalyst could be reused three cycles with the same efficiency. Finally, reactions of other ketoximes were also investigated.
Lewis acid-assisted N-fluorobenzenesulfonimide-based electrophilic fluorine catalysis in Beckmann rearrangement
Xie, Fukai,Du, Chuan,Pang, Yadong,Lian, Xu,Xue, Chentao,Chen, Yanyu,Wang, Xuefei,Cheng, Maosheng,Guo, Chun,Lin, Bin,Liu, Yongxiang
supporting information, p. 5820 - 5824 (2016/12/06)
A microwave-assisted N-fluorobenzenesulfonimide (NFSI)/Lewis acid-catalyzed Beckmann rearrangement was developed. The remarkable promotion to the electrophilicity of NFSI by Lewis acids was illustrated utilizing a series of readily available oxime substrates. The action model between NFSI and Lewis acids was probed by control experiments and theoretical calculations.
Synthesis and structural analysis of halogen substituted fibril formation inhibitors of Human Transthyretin (TTR)
Ciccone, Lidia,Nencetti, Susanna,Rossello, Armando,Stura, Enrico Adriano,Orlandini, Elisabetta
, p. 40 - 51 (2016/12/03)
Transthyretin (TTR), a β-sheet-rich tetrameric protein, in equilibrium with an unstable amyloidogenic monomeric form is responsible for extracellular deposition of amyloid fibrils, is associated with the onset of neurodegenerative diseases, such as senile
