Imidazotetrazines as Weighable Diazomethane Surrogates for Esterifications and Cyclopropanations
作者:Riley L. Svec、Paul J. Hergenrother
DOI:10.1002/anie.201911896
日期:2020.1.27
Diazomethane is one of the most versatile reagents in organic synthesis, but its utility is limited by its hazardous nature. Although alternative methods exist to perform the unique chemistry of diazomethane, these suffer from diminished reactivity and/or correspondingly harsher conditions. Herein, we describe the repurposing of imidazotetrazines (such as temozolomide, TMZ, the standard of care for
One-pot synthesis of quaternary pyridinium salts and tetrahydropyridine derivatives of fusidane triterpenoids
作者:Elvira R. Shakurova、Elena V. Salimova、Ekaterina S. Mescheryakova、Lyudmila V. Parfenova
DOI:10.1007/s10593-019-02602-6
日期:2019.12
An efficient one-pot method was developed for the preparation of quaternary pyridiniumsalts and tetrahydropyridine derivatives of fusidane triterpenoids, based on the use of Tempo \( }^+}\mathrmBr}}_3^-} \) as the halogenating agent and pyridine as the reagent and solvent.
Synthesis of Fusidic Acid Derivatives Yields a Potent Antibiotic with an Improved Resistance Profile
作者:Martin Garcia Chavez、Alfredo Garcia、Hyang Yeon Lee、Gee W. Lau、Erica N. Parker、Kailey E. Komnick、Paul J. Hergenrother
DOI:10.1021/acsinfecdis.0c00869
日期:2021.2.12
Fusidic acid (FA) is a potent steroidal antibiotic that has been used in Europe for more than 60 years to treat a variety of infections caused by Gram-positivepathogens. Despite its clinical success, FA requires significantly elevated dosing (3 g on the first day, 1.2 g on subsequent days) to minimize resistance, as FA displays a high resistance frequency, and a large shift in minimum inhibitory concentration
夫西地酸 (FA) 是一种强效甾体抗生素,已在欧洲使用了 60 多年,用于治疗由革兰氏阳性病原体引起的各种感染。尽管在临床上取得了成功,但 FA 需要显着增加剂量(第一天 3 g,随后几天 1.2 g)以最小化耐药性,因为 FA 显示出高耐药频率,并且观察到耐药细菌的最小抑制浓度有很大变化。尽管努力在这些方面进行改进,但所有先前构建的 FA 衍生物对革兰氏阳性菌的抗菌活性都比母体天然产物更差。在这里,我们报告了一种新型 FA 类似物的产生,该类似物对金黄色葡萄球菌( S. aureu s) 和金黄色葡萄球菌的临床分离株具有同等效力。与 FA 相比,粪肠球菌( E. faecium ) 以及改进的体外抗性谱。重要的是,这种新化合物在软组织小鼠感染模型中对金黄色葡萄球菌FA 抗性菌株显示出功效。这项工作描绘了有效抗生素活性所必需的 FA 的结构特征,并证明可以改善该支架和靶标的耐药性。
<i>O</i>-Methylation of carboxylic acids with streptozotocin
作者:Li-Yan Zeng、Yang Liu、Jiakun Han、Jinhong Chen、Shuwen Liu、Baomin Xi
DOI:10.1039/d2ob00578f
日期:——
The clinically used DNA-alkylating drug streptozotocin (STZ) was investigated using a simple work-up as an O-methylating agent to transform various carboxylicacids, sulfonic acids and phosphorous acids into corresponding methyl esters, and did so with yields of up to 97% in 4 h at room temperature. Good substrate tolerance was observed, and benefited from the mild conditions and compatibility of the
临床上使用的 DNA 烷基化药物链脲佐菌素 (STZ) 使用简单的后处理作为O-甲基化剂将各种羧酸、磺酸和亚磷酸转化为相应的甲酯进行了研究,其产率高达 97 % 在室温下 4 小时。观察到良好的底物耐受性,这得益于温和的条件和与水反应的相容性。
A Base‐Free, Low Temperature Click and Release Reaction for the In Situ Generation of Diazomethane
作者:Luke S. Schembri、Esther Olaniran、Marcus Söderström、Bobo Skillinghaug、Luke R. Odell
DOI:10.1002/adsc.202300132
日期:2023.6.13
to the reaction medium. Herein, we present a low temperature and base-free in situ synthesis of diazomethane via a “click and release” reaction between an enamine and sulfonyl azide. Its utility is exemplified by the synthesis of diverse methyl esters in yields of up to 93%. Moreover, diazoketone synthesis from in situ generated diazomethane and acid chlorides was demonstrated for the first time. Finally