Design and semisynthesis of new herbicide as 1,2,3-triazole derivatives of the natural maslinic acid
摘要:
Interesting biological activities (anti-inflammatory, anticancer, antiviral, antioxidant, antidiabetic...) have been reported for maslinic acid (MA) and MA-based compounds. In continuation of our previous work on MA, herbicide potential of Tunisian plant extracts and 1,4-triazolyl derivatives of MA, we now wish to report semisynthesis of new MA-based triazole hybrid compounds with herbicide potential. These compounds were synthesized through Cu-catalyzed azide-alkyne cycloaddition (CuAAC) under microwave irradiation conditions between propargylated MA and a series of phthalimide azides. Here, the first partner of CuAAC reaction (propargylated MA) resulted from propargylation of C-28 carboxylic acid group of isolated MA from the well-known Mediterranean plant Olea europaea L. (Oleaceae). So far, phthalimide azide derivatives were achieved by trapping of N-acyliminium ion, in-situ generated under catalytic condition of Bi(OTf)(3), by aromatic nucleophiles. The cycloaddition reaction afforded regiospecifically 1,4-disubstituted triazoles in good yields. The latter hybrid compounds were shown to exhibit a high inhibition potential of seed germination. This constitutes the first step in development of potent herbicides since one of the final semisynthesized structures can serve as a promising lead candidate for further studies.
报道了用于烷基叠氮化物合成的脂肪族羧酸的催化脱羧氮化。通过使用K 2 S 2 O 8作为氧化剂和PhSO 2 N 3作为氮源,由易于获得的脂肪族羧酸制备出一系列的叔,仲和伯有机叠氮化物。EPR实验充分证明在该过程中产生了烷基自由基过程,DFT计算进一步支持SET过程,然后逐步进行S H 2反应以提供叠氮化物产物。
Conversion of leucomycin-A3 antibiotic into novel triazole analogues via regio- and diastereoselective SN1′ substitution with allylic rearrangement and 1,3-dipolar cycloaddition of CuAAC type
nucleophilic substitution of josamycin’s dienol system in the aglycone yielded novel products having an alkyne group attached at the C(13) carbon atom. Detailed 1H–1H NOESY and 1H–13C HMBC investigations together with DFT calculations indicated the C(13S) configuration within the structures of alkyne-functionalized leucomycins. Analysis of the relationship between the rate of nucleophilic substitution and concentration
考虑到交联霉素(leucomycin-A 3)缩醛官能团的化学反应复杂,醛缩醛的醛化反应继而亲核取代交联糖苷配基中的乙醛,产生了在C(13)碳原子上连接有炔基的新产物。详细的1 H– 1 H NOESY和1 H– 13 C HMBC研究以及DFT计算表明C(13 S)在炔烃官能化的白霉素的结构内进行配置。对亲核取代速率与浓度之间关系的分析揭示了取代的单分子机理,其中离去基团的质子化是速率确定步骤。使用CuAAC反应进一步将糖苷配基上的炔烃取代基转化为可得到带有取代的1,2,3-三唑环的新型杂环白霉素类似物。
16-Membered Macrolide Lactone Derivatives Bearing a Triazole-Functionalized Arm at the Aglycone C13 Position as Antibacterial and Anticancer Agents
indexes [SI; calculated relative to the human dermal fibroblast (HDF) cell line], even higher than that of the reference compound cytarabine. Results of molecular docking studies of this type of macrolideantibiotics at the ribosomal tunnel, together with experimentally determined lipophilicity and aqueous solubility values, as well as biological assay data revealed the importance of the introduced functional
Structure and evaluation of antibacterial and antitubercular properties of new basic and heterocyclic 3-formylrifamycin SV derivatives obtained via ‘click chemistry’ approach
time because of the high volatility of substrates, an unexpected intramolecular condensation with the formation of 3,4-dihydrobenzo[g]quinazoline heterocyclic system took place. Structures of new derivatives in solution were determined using one- and two-dimensional NMR methods and FT-IR spectroscopy. Computational DFT and PM6 methods were employed to correlate their conformation and acid–base properties
Efficient One-Pot Synthesis of 1,2,3-Triazoles from Benzyl and Alkyl Halides
作者:Karol Kacprzak
DOI:10.1055/s-2005-864809
日期:——
An efficient one-pot method for the preparation of 1,2,3-triazoles by 1,3-dipolarcycloaddition of in situ generated azides and alkynes is presented. This facile method can be applied to benzyl or alkyl halides and pure products are isolated by simple filtration.
Lewis Acid Catalyzed Site-Selective Cycloadditions of 2,6-Diazasemibullvalenes with Isocyanides, Azides, and Diazo Compounds for the Synthesis of Diaza- and Triazabrexadiene Derivatives
作者:Shaoguang Zhang、Wen-Xiong Zhang、Zhenfeng Xi
DOI:10.1002/anie.201210126
日期:2013.3.18
Unprecedented cycloaddition pathways: Lewisacidcatalyzed cycloadditions of 2,6‐diazasemibullvalenes with isocyanides, azides, and diazo compounds lead to structurally interesting and otherwise unavailable cage diaza‐ and triazabrexadiene derivatives. Unique rearrangement/cycloaddition pathways are revealed.