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Updated: Sep 13, 2025

Synthesis and Purification of Iodoaziridines Involving Quantitative Selection of the Optimal Stationary Phase for Chromatography
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伪氨酸生物合成的最后步骤具有环-收缩性N-N键形成的特点

Lingyi Zhu1, Xiaozheng Wang1, Qing Shi1

  • 1State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.

JACS Au
|August 1, 2025
PubMed
概括

研究人员阐明了伪丁 (PSD) 生物合成的最后步骤,揭示了环收缩过程中一种新的酶催化N-N键的形成. 这一发现加深了我们对天然产品生物合成和酶机制的理解.

关键词:
N−N 债券 N−N 债券PsdBB 在线阅读生物合成生物合成假名的丁胺是什么意思邻近的氧基酸盐超级家族.

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Bromination and chlorination of aromatic rings by electrophilic aromatic substitution reactions are easily achieved, but fluorination and iodination are difficult to achieve. Fluorine is so reactive that its reaction with benzene is difficult to control, resulting in poor yields of monofluoroaromatic products. To address this, Selectfluor reagent is used as a fluorine source in which a fluorine atom is bonded to a positively charged nitrogen.
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Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
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All ortho–para directors, excluding halogens, are activating groups. These groups donate electrons to the ring, making the ring carbons electron-rich. Consequently, the reactivity of the aromatic ring towards electrophilic substitution increases. For instance, the nitration of anisole is about 10,000 times faster than the nitration of benzene. The electron-donating effect of the methoxy group in anisole activates the ortho and para positions on the ring and stabilizes the corresponding...
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Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
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Primary amines react with carbonyl compounds—aldehydes and ketones—to generate imines. Imines consist of a C=N double bond and are named Schiff bases after its discoverer—the German chemist Hugo Schiff. On the other hand, secondary amines react with carbonyl compounds to give enamines. In enamines, the presence of a C=C double bond adjacent to the nitrogen atom leads to the delocalization of the lone pair.
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Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
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