57699-28-2Relevant academic research and scientific papers
Unraveling two pathways for NHPI-mediated electrocatalytic oxidation reaction
Xu, Leitao,Yi, Yangjie,Hu, Sideng,Ye, Jiao,Hu, Aixi
, (2021/11/30)
Two pathways for N-hydroxyphthalimide (NHPI)-mediated electrocatalytic oxidation using phenylacetate derivatives as template substrates were first reported for benzylic C[sbnd]H oxidation to oxygenated and non-oxygenated products. DFT calculation indicates that the hydrogen-atom transfer (HAT) process between phthalimido-N-oxyl (PINO) and substrate is a rate-determined step. Aromatic α-keto esters and 2-((1,3-dioxoisoindolin-2-yl)oxy)-2-aryl acetate obtained by cross-coupling between benzylic radical and PINO can be selectively synthesized through controlling the concentration of PINO radical. This method provides a deep understanding for selective weak C[sbnd]H oxidation using NHPI as redox mediator.
Preparation method of alpha-ketoester compound
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Paragraph 0114-0117, (2021/04/21)
The invention discloses a preparation method of an alpha-ketone ester compound. The method specifically comprises the following operation steps: adding raw materials alpha-diazo ester and an organic photocatalyst into a reaction flask, then adding an organic solvent, and reacting for 2-12 hours in air at room temperature under the irradiation of a visible light lamp; after the reaction is monitored by thin-layer chromatography (TLC), stopping the reaction, and extracting a reaction solution by using ethyl acetate; concentrating the extracting solution under reduced pressure to obtain a crude product, and performing column chromatography separation on the crude product to obtain the alpha-diazonium ester compound. According to the preparation method, clean visible light is used as reaction energy, cheap organic dye is used as a photocatalyst, air is used as a green oxidizing agent and an oxygen source, and the preparation method has the advantages of simplicity and convenience in operation, no metal residue and mild reaction conditions.
Tandem Photoredox-Chiral Phosphoric Acid Catalyzed Radical-Radical Cross-Coupling for Enantioselective Synthesis of 3-Hydroxyoxindoles
Zhang, Yang,Ye, Dan,Shen, Lei,Liang, Kangjiang,Xia, Chengfeng
supporting information, p. 7112 - 7117 (2021/09/14)
A photochemical protocol that couples diarylamines and α-ketoesters to afford the chiral 3-hydroxyoxindoles through tandem photoredox and chiral phosphoric acid catalysis is developed. The reaction involves an enantioselective photochemical radical-radical cross-coupling process. The chiral phosphoric acid is discovered to play crucial roles by decreasing the reductive potentials of α-ketoesters and stereocontrolling the downstream asymmetric radical-radical cross-coupling via the formation of pentacoordinate complex.
Silyl Cyanopalladate-Catalyzed Friedel-Crafts-Type Cyclization Affording 3-Aryloxindole Derivatives
Ece, Hamdiye,Tange, Yuji,Yurino, Taiga,Ohkuma, Takeshi
supporting information, p. 935 - 939 (2021/02/22)
3-Aryloxindole derivatives were synthesized through a Friedel-Crafts-type cyclization. The reaction was catalyzed by a trimethylsilyl tricyanopalladate complex generated in situ from trimethylsilyl cyanide and Pd(OAc) 2. Wide varieties of diethyl phosphates derived from N -arylmandelamides were converted almost quantitatively into oxindoles. When N, N -dibenzylamide was used instead of an anilide substrate, a benzo-fused δ-lactam was obtained. An oxindole product was subjected to substitution reactions to afford 3,3-diaryloxindoles with two different aryl groups.
Visible-Light-Induced Catalyst-Free Carboxylation of Acylsilanes with Carbon Dioxide
Fan, Zhengning,Yi, Yaping,Chen, Shenhao,Xi, Chanjuan
, p. 2303 - 2307 (2021/04/05)
Intermolecular carbon-carbon bond formation between acylsilanes and carbon dioxide (CO2) was achieved by photoirradiation under catalyst-free conditions. In this reaction, siloxycarbenes generated by photoisomerization of the acylsilanes added to the C═O bond of CO2 to give α-ketocarboxylates, which underwent hydrolysis to afford α-ketocarboxylic derivatives in good yields. Control experiments suggest that the generated siloxycarbene is likely to be from the singlet state (S1) of the acylsilane and the addition to CO2 is not in a concerted manner.
Green preparation method of aryl [alpha]-keto ester compound
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Paragraph 0065-0068, (2020/05/30)
The invention discloses a green preparation method of an aryl [alpha]-keto ester compound. The method comprises the specific steps that an [alpha]-diazo compound serves as a reaction raw material, copper sulfate serves as a catalyst, water serves as a solvent, a target product aryl [alpha]-keto ester compound is prepared through a reaction at the temperature of 60 DEG C, the structural general formula of the [alpha]-diazo compound is shown in the specification, and the structural general formula of the correspondingly prepared target product aryl [alpha]-keto ester compound is shown in the specification. The method for synthesizing the target product aryl [alpha]-keto ester compound by catalyzing the [alpha]-diazo compound derivative with copper sulfate has the advantages that the reactioncondition is green and mild, the catalyst is cheap and easy to obtain, the operation is simple and convenient, the yield is relatively high, the universality of a reaction substrate is wide, and thelike.
Copper(I)-catalyzed aerobic oxidation of α-diazoesters
Xu, Changming,Bai, Lei,Wang, Yongchang
, p. 12579 - 12584 (2020/11/09)
A practical Cu-catalyzed oxidation of α-diazoesters to α-ketoesters using molecular oxygen as an oxidant has been developed. Both electron-poor and electron-rich aryl α-diazoesters are suitable substrates and provide the α-ketoesters in good yields. In this oxidative system, α-diazo-β-ketoesters are also compatible as substrates but unexpectedly furnish α-ketoesters via C-C bond cleavage, rather than the vicinal tricarbonyl products.
Visible-Light-Enabled Paternò-Büchi Reaction via Triplet Energy Transfer for the Synthesis of Oxetanes
Rykaczewski, Katie A.,Schindler, Corinna S.
supporting information, p. 6516 - 6519 (2020/09/02)
One of the most efficient ways to synthesize oxetanes is the light-enabled [2 + 2] cycloaddition reaction of carbonyls and alkenes, referred to as the Paternò-Büchi reaction. The reaction conditions for this transformation typically require the use of hig
Method for preparing spiro beta-lactam
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Paragraph 0048-0051, (2020/07/12)
The invention discloses a method for preparing spiro beta-lactam. The method comprises the following step: carrying out [2+1] cyclization reaction on beta-lactam and keto ester under the condition ofa phosphine catalyst to generate spiro beta-lactam. The
Cobalt-Catalyzed Transfer Hydrogenation of α-Ketoesters and N-Cyclicsulfonylimides Using H2O as Hydrogen Source
Gao, Yang,Zhang, Xuexin,Laishram, Ronibala Devi,Chen, Jingchao,Li, Kangkui,Zhang, Keyang,Zeng, Guangzhi,Fan, Baomin
supporting information, p. 3991 - 3997 (2019/08/02)
A Co-catalyzed effective transfer hydrogenation of various α-ketoesters and N-cyclicsulfonylimides by safe and environmentally benign H2O as hydrogen source is described. The reaction used easily available and easy to handle zinc metal as a reductant. Interestingly, the catalytic system does not require ligand for reduction of N-cyclicsulfonylimides. (Figure presented.).
