581-97-5Relevant articles and documents
Hypervalent Iodine Reagent-Promoted Hofmann-Type Rearrangement/Carboxylation of Primary Amides
Wang, Xia,Yang, Peng,Hu, Bo,Zhang, Qian,Li, Dong
, p. 2820 - 2826 (2021/02/01)
A novel transformation of primary amides to secondary amides promoted by hypervalent iodine reagents was developed. The hypervalent iodine reagent-mediated Hofmann-type rearrangement generated an isocyanate intermediate, which was subsequently trapped by an in situ generated carboxylic acid from the hypervalent iodine reagent to provide the corresponding secondary amides. This method provided a facile and efficient route for the synthesis of secondary amides from primary amides and also revealed novel reactivities of hypervalent iodine reagents.
Dehydrative Beckmann rearrangement and the following cascade reactions
Liu, Yinghui,Wei, Yongjiao,Xie, Lan-Gui
supporting information, (2021/11/16)
The Beckmann rearrangement has been predominantly studied for the synthesis of amide and lactam. By strategically using the in situ generated Appel's salt or Mitsunobu's zwitterionic adduct as the dehydrating agent, a series of Beckmann rearrangement and following cascade reactions have been developed herein. The protocol allows the conversion of various ketoximes into amide, thioamide, tetrazole and imide products in modular procedures. The generality and tolerance of functionalities of this method have been demonstrated.
Method for promoting acylation of amine or alcohol by carbon dioxide
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Paragraph 0033-0034, (2021/05/29)
The invention relates to a method for promoting acylation of amine or alcohol by carbon dioxide, which comprises the following steps of: mixing an amine compound, carboxylate or thiocarboxylate compound and a reaction solvent under the action of carbon dioxide, and reacting to obtain an amide compound, or under the action of carbon dioxide, mixing the alcohol compound, the thiocarboxylate compound and the reaction solvent [gamma]-valerolactone, and reacting to obtain the ester compound. According to the invention, under the promotion action of carbon dioxide, carboxylate or thiocarboxylate is used as an acylation reagent, and amine and alcohol are converted into amide and ester compounds in the absence of a transition metal catalyst, so that acylation reagents such as acyl chloride or anhydride with irritation and corrosivity are avoided; and the method has the advantages of simple operation, mild reaction conditions, high tolerance of substrate functional groups, strong applicability and high yield, and provides an efficient, reliable and economical preparation method for synthesis of amide and ester compounds.
ION CHANNEL ANTAGONISTS/BLOCKERS AND USES THEREOF
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Paragraph 24; 32, (2021/06/22)
Provided are ion channel antagonists/blockers and uses thereof. Specifically, it provides the compounds of formula (I) or pharmaceutically acceptable salts, stereoisomers, solvates or prodrugs, preparation method therefor and application thereof. Definition of each group in the formula can be found in the specification for details. Provided is also pharmaceutical composition useful for treatment of heart disease and other ion channel related diseases.
Cu(OTf)2-Mediated Cross-Coupling of Nitriles and N-Heterocycles with Arylboronic Acids to Generate Nitrilium and Pyridinium Products**
Bell, Nicola L.,Xu, Chao,Fyfe, James W. B.,Vantourout, Julien C.,Brals, Jeremy,Chabbra, Sonia,Bode, Bela E.,Cordes, David B.,Slawin, Alexandra M. Z.,McGuire, Thomas M.,Watson, Allan J. B.
supporting information, p. 7935 - 7940 (2021/03/03)
Metal-catalyzed C–N cross-coupling generally forms C?N bonds by reductive elimination from metal complexes bearing covalent C- and N-ligands. We have identified a Cu-mediated C–N cross-coupling that uses a dative N-ligand in the bond-forming event, which, in contrast to conventional methods, generates reactive cationic products. Mechanistic studies suggest the process operates via transmetalation of an aryl organoboron to a CuII complex bearing neutral N-ligands, such as nitriles or N-heterocycles. Subsequent generation of a putative CuIII complex enables the oxidative C–N coupling to take place, delivering nitrilium intermediates and pyridinium products. The reaction is general for a range of N(sp) and N(sp2) precursors and can be applied to drug synthesis and late-stage N-arylation, and the limitations in the methodology are mechanistically evidenced.
Efficient nitriding reagent and application thereof
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Paragraph 0417-0419, (2021/03/31)
The invention discloses an efficient nitriding reagent and application thereof, wherein the nitriding reagent comprises nitrogen oxide, an active agent, a reducing agent and an organic solvent. By applying the nitriding reagent, nitrogen-containing compounds such as amide, nitrile and the like can be produced, and the method is simple in condition, low in waste discharge amount and simple in reaction equipment.
An Electrochemical Beckmann Rearrangement: Traditional Reaction via Modern Radical Mechanism
Tang, Li,Wang, Zhi-Lv,He, Yan-Hong,Guan, Zhi
, p. 4929 - 4936 (2020/08/21)
Abstract: Electrosynthesis as a potential means of introducing heteroatoms into the carbon framework is rarely studied. Herein, the electrochemical Beckmann rearrangement, i. e. the direct electrolysis of ketoximes to amides, is presented for the first time. Using a constant current as the driving force, the reaction can be easily carried out under neutral conditions at room temperature. Based on a series of mechanistic studies, a novel radical Beckmann rearrangement mechanism is proposed. This electrochemical Beckmann rearrangement does not follow the trans-migration rule of the classical Beckmann rearrangement.
Direct synthesis of secondary amides from ketones through Beckmann rearrangement using O-(mesitylsulfonyl)hydroxylamine
Chandra, Dinesh,Verma, Saumya,Pandey, Chandra Bhan,Yadav, Ajay K.,Kumar, Puneet,Tiwari, Bhoopendra,Jat, Jawahar L.
supporting information, (2020/03/23)
The Beckmann rearrangement is a versatile method for the preparation of secondary amides from ketones via oxime intermediates and has been widely used in the synthesis of bioactive natural products and pharmaceuticals. Herein, we have developed a highly efficient direct method for the preparation of secondary amides and lactams from ketones using O-(mesitylsulfonyl)hydroxylamine (MSH). The reactions proceed rapidly at room temperature under mild condition without requiring any additive, and tolerate multiple functional groups. A simple aqueous work-up often furnished the products in excellent yield with high purity.
Zinc(II)-Catalyzed Synthesis of Secondary Amides from Ketones via Beckmann Rearrangement Using Hydroxylamine-O-sulfonic Acid in Aqueous Media
Verma, Saumya,Kumar, Puneet,Khatana, Anil K.,Chandra, Dinesh,Yadav, Ajay K.,Tiwari, Bhoopendra,Jat, Jawahar L.
, p. 3272 - 3276 (2020/11/02)
A zinc(II)-catalyzed single-step protocol for the Beckmann rearrangement using hydroxylamine-O-sulfonic acid (HOSA) as the nitrogen source in water was developed. This direct method efficiently produces secondary amides under open atmosphere in a pure form after basic aqueous workup. It isenvironmentally benign and operationally simple.
Chlorotropylium Promoted Conversions of Oximes to Amides and Nitriles
Xu, Jiaxi,Gao, Yu,Li, Zhenjiang,Liu, Jingjing,Guo, Tianfo,Zhang, Lei,Wang, Haixin,Zhang, Zhihao,Guo, Kai
, p. 311 - 315 (2020/01/25)
Chlorotropylium chloride as a catalyst for the transformations of oximes, ketones, and aldehydes to their corresponding amides and nitriles in excellent yields (up to 99 %) and in short reaction times (mostly 10–15 min). Oximes were electrophilically attacked on the hydroxyl oxygen by chlorotropylium. The produced tropylium oxime ethers were the key intermediates, of which the ketoxime ether led to amide through Beckmann rearrangement, and the aldoxime ether led to nitrile by nitrogen base DBU assisted formal dehydration. This chlorotropylium activation protocol offered general, mild, and efficient avenues bifurcately from oximes to both amides and nitriles by one organocatalyst.
