180261-48-7Relevant articles and documents
β-Cyclodextrin as a scaffold for supramolecular chemistry, to reverse the regioselectivity of nitrile oxide cycloadditions
Meyer, Adam G.,Easton, Christopher J.,Lincoln, Stephen F.,Simpson, Gregory W.
, p. 9069 - 9075 (1998)
β-Cyclodextrin has been used as a molecular scaffold, whereby tethering dipolarophiles to the cyclodextrin and then allowing preassociation of the modified cyclodextrins with aromatic nitrile oxides, as host-guest complexes, controls the relative orientations of the dipoles and the dipolarophiles in their cycloadditions. In this manner it has been possible to reverse the usual regioselectivity of cycloadditions of nitrile oxides, as illustrated by reactions with a terminal alkene, a terminal alkyne, and a 1,2-disubstituted alkene. For example, in aqueous solution, 4-tertbutylbenzonitrile oxide reacted with 6(A)-deoxy-6(A)-propynamido-β-cyclodextrin to give the corresponding 4- and 5-substituted isoxazoles, in a 15:1 ratio. With DMF as the solvent, to reduce the extent of host-guest complexation, the product ratio was 1:1.5. The role of complexation in these reactions is also demonstrated by contrasting these results with that of the reaction of the nitrile oxide with methyl propynoate, which afforded only the 5-substituted cycloaddition product. Molecular recognition by the cyclodextrin scaffolds was demonstrated through treatment of 4-tertbutylbenzonitrile oxide with an equimolar mixture of 6(A)-deoxy-6(A)-propynamido-β-cyclodextrin and methyl propynoate, in aqueous solution, which gave only the cycloadducts from reaction of the cyclodextrin dipolarophile.
Electrochemical synthesis of 1,2,4-oxadiazoles from amidoximes through dehydrogenative cyclization
Hu, Aixi,Jiang, chan,Li, mingfang,Xu, Leitao,Ye, Jiao,Yi, Yangjie
supporting information, p. 10611 - 10616 (2021/12/27)
A convenient and efficient method for the generation of the iminoxy radical through anodic oxidation was developed for the synthesis of 3,5-disubstituted 1,2,4-oxadiazoles fromN-benzyl amidoximes. The transformation proceeds through 1.5-Hydrogen Atom Transfer (1,5-HAT) and intramolecular cyclization. The process features simple operation, mild conditions, broad substrate scope and high functional group compatibility, and provides a facile and practical way for the preparation of 1,2,4-oxadiazoles.
Design, synthesis of novel 4,5-dihydroisoxazole-containing benzamide derivatives as highly potent FtsZ inhibitors capable of killing a variety of MDR Staphylococcus aureus
Song, Di,Bi, Fangchao,Zhang, Nan,Qin, Yinhui,Liu, Xingbang,Teng, Yuetai,Ma, Shutao
supporting information, (2020/09/11)
Antibiotic resistance among clinically significant bacterial pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant S. aureus (VRSA) is becoming a prevalent threat to public health, and new antibacterial agents with novel mechanisms of action hence are in an urgent need. As a part of continuing effort to develop antibacterial agents, we rationally designed and synthesized two series of 4,5-dihydroisoxazol-5-yl and 4,5-dihydroisoxazol-3-yl-containing benzamide derivatives that targeted the bacterial cell division protein FtsZ. Evaluation of their activity against a panel of Gram-positive and -negative pathogens revealed that compound A16 possessing the 4,5-dihydroisoxazol-5-yl group showed outstanding antibacterial activity (MIC, ≤0.125–0.5 μg/mL) against various testing strains, including methicillin-resistant, penicillin-resistant and clinical isolated S. aureus strains. Besides, further mouse infection model revealed that A16 could be effective in vivo and non-toxic to Hela cells. Finally, a detailed discussion of structure-activity relationships was conducted, referring to the docking results. It is worth noting that substituting a 4,5-dihydroisoxazole ring for the isoxazole ring not only broadened the antibacterial spectrum but also resulted in a significant increase in antibacterial activity against S. aureus strains. Taken together, these results suggest a promising chemotype for the development of new FtsZ-targeting bactericidal agents.
