13964-22-2Relevant articles and documents
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Muskat
, p. 2449,2453 (1934)
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Glycosyl isoxazole compound, preparation method thereof and bactericide
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Paragraph 0178-0181; 0185, (2021/04/07)
The invention relates to the technical field of bactericidal materials, and particularly relates to a glycosyl isoxazole compound, a preparation method thereof and a bactericide. The glycosyl isoxazole compound has a structural general formula shown in the description, wherein R1 is selected from any one of substituted or unsubstituted aromatic groups, and R2 is selected from any one of H, acetyl, benzyl and propargyl. According to the invention, a natural saccharide compound is adopted as the framework, the safety is provided, the toxicity is low, the selectivity is high, residue is not easily generated, the environmental compatibility is good, the active group isoxazole structure is further introduced, and the obtained glycosyl isoxazole compound has advantages of safety, high efficiency, low toxicity, low residue, broad spectrum, resistance generation resistance resistance resistance generation resistance and the like, and further has excellent bactericidal activity.
Zn-Catalyzed tert-Butyl Nicotinate-Directed Amide Cleavage as a Biomimic of Metallo-Exopeptidase Activity
Wybon, Clarence C. D.,Mensch, Carl,Hollanders, Charlie,Gadais, Charlène,Herrebout, Wouter A.,Ballet, Steven,Maes, Bert U. W.
, p. 203 - 218 (2018/01/17)
A two-step catalytic amide-to-ester transformation of primary amides under mild reaction conditions has been developed. A tert-butyl nicotinate (tBu nic) directing group is easily introduced onto primary amides via Pd-catalyzed amidation with tert-butyl 2-chloronicotinate. A weak base (Cs2CO3 or K2CO3) at 40-50 °C can be used provided that 1,1′-bis(dicyclohexylphosphino)ferrocene is selected as ligand. The tBu nic activated amides subsequently allow Zn(OAc)2-catalyzed nonsolvolytic alcoholysis in tBuOAc at 40-60 °C under neutral reaction conditions. The activation mechanism is biomimetic: the C3-ester substituent of the pyridine in the directing group populates the trans-conformer suitable for Zn-chelation, C=Oamide-Zn-Ndirecting group, and Zn-coordinated alcohol is additionally activated as a nucleophile by hydrogen bonding with the acetate ligand of the catalyst. Additionally, the acetate ligand assists in intramolecular O-to-N proton transfer. The chemoselectivity versus other functional groups and compatibility with challenging reaction partners, such as peptides, sugars, and sterols, illustrates the synthetic applicability of this two-step amide cleavage method. The tBu nic amides do not require purification before cleavage. Preliminary experiments also indicate that other weak nucleophiles can be used such as (hetero)arylamines (transamidation) as exemplified by 8-aminoquinoline.