4‐cyclodiphosphate synthase (IspF) is an essential enzyme for the biosynthesis of isoprenoid precursors in plants and many human pathogens. The protein is an attractive target for the development of anti‐infectives and herbicides. Using a photometric assay, a screen of 40 000 compounds on IspF from Arabidopsis thaliana afforded symmetrical aryl bis‐sulfonamides that inhibitIspF from A. thaliana (AtIspF)
2-甲基赤藓糖醇2,4-环二磷酸合酶(IspF)是植物和许多人类病原体中类异戊二烯前体生物合成的必需酶。该蛋白是开发抗感染剂和除草剂的有吸引力的靶标。使用光度测定法,对拟南芥IspF上的40 000种化合物进行筛选,得到对称的芳基双磺酰胺,可抑制拟南芥(At IspF)和恶性疟原虫(Pf IspF)的IspF,IC 50值在微摩尔范围内。在邻-二磺酰胺结构基元是用于抑制活性至关重要。通过平行合成获得的最佳衍生物显示IC 50的1.4μ值米针对Pf的ISPF和240Ñ米针对在ISPF。在2kg ha -1的剂量下观察到大量除草活性。分子模型研究是针对新型非对称磺酰胺IspF抑制剂的发现进行计算机搜索的基础。发现设计的化合物在两位数的微摩尔IC 50范围内表现出抑制活性。
I<sub>2</sub>-Mediated Intramolecular C–H Amidation for the Synthesis of N-Substituted Benzimidazoles
practical intramolecular C–H amidation methodology has been developed using molecular iodine under basic conditions. The required imine substrates were readily obtained by condensation of simple o-phenylenediamine derivatives and aldehydes. The transition-metal-free cyclization reaction described here works well with crude imines and allows for the sequential synthesis of N-protected benzimidazoles
An intramolecular Cu-catalyzed asymmetric propargylic [4 + 2] cycloaddition of bis-N-nucleophile-functionalized propargylic esters has been realized in the support of a chiral tridentate N-ligand, (S,S)-Pybox-diOAc, leading to chiral tetrahydroisoindolo[2,1-a]quinoxalines in high yields and with good to excellent enantioselectivities. The reaction features high efficiency, simplicity, and broad substrate
在手性三齿 N-配体 ( S , S )-Pybox-diOAc 的支持下,实现了双-N-亲核试剂官能化的炔丙基酯的分子内 Cu 催化的不对称炔丙基 [4 + 2] 环加成反应,从而产生手性四氢异吲哚[2,1- a ]喹喔啉的收率高,对映选择性良好。该反应具有高效、简单和广泛的底物范围,从而为立体选择性获得原本难以合成的光学活性多环杂环骨架提供了强大而简洁的策略。
Palladium-Catalyzed Intramolecular Sulfonamidation/Oxidation of Imines: Access to Multifunctional Benzimidazoles
作者:Shaomin Fu、Huanfeng Jiang、Yuanfu Deng、Wei Zeng
DOI:10.1002/adsc.201100370
日期:2011.10
O-Sulfonamidophenylimines undergo intramolecularsulfonamidation/oxidation to produce 1,2-disubstituted benzimidazoles upon treatment with palladium(II) chloride/(diacetoxyiodo)benzene and potassium carbonate at room temperature. The substituent scope at the 2-position of the benzimidazole can be extended to alkyl, aryl, alkenyl, acyl, and ester functional groups under mild conditions.
An electrochemical method for the synthesis of N-substituted 2-aminobenzimidazoles through a NaI-mediated desulfurization–cyclization process is reported. This electrosynthesis method utilizes cost-effective NaI as both a mediator and an electrolyte in a catalytic amount (0.2 equiv), replacing traditional oxidizing reagents. N-Substituted o-phenylenediamines and isothiocyanates undergo a thiourea
报道了一种通过 NaI 介导的脱硫环化过程合成N-取代 2-氨基苯并咪唑的电化学方法。这种电合成方法利用经济高效的 NaI 作为介体和催化量(0.2 当量)的电解质,取代了传统的氧化剂。 N-取代的邻苯二胺和异硫氰酸酯经过硫脲形成/环化/脱硫过程,在单个反应容器中提供N-取代的2-氨基苯并咪唑(55个实例,产率高达98%)。重要的是,这种电化学方法适用于克级合成,保持反应效率。