Transition-metal-free access to carbazoles was achieved through base-mediated intramolecular C–C bond formation. Reactions of N-substituted o-halodiarylamines with potassium tert-butoxide in the presence of ethylene glycol or 1,10-phenanthroline provided carbazoles in moderate to excellent yields. This transformation may proceed through a radical pathway according to a control experiment with a radical scavenger.

Herein we report a new way to identify chemical elicitors that induce resistance in rice to herbivores. Using this method, by quantifying the induction of chemicals for GUS activity in a specific screening system that we established previously, 5 candidate elicitors were selected from the 29 designed and synthesized phenoxyalkanoic acid derivatives. Bioassays confirmed that these candidate elicitors could induce plant defense and then repel feeding of white-backed planthopper Sogatella furcifera.We used the relative induction of GUS activity as a screening tool for identifying new chemical elicitors that induce resistance in rice to the white-backed planthopper Sogatella furcifera.

To provide essential information for peptide inhibitor design, the interactions of Eps15 homology domain of Eps15 homology domain-containing protein 1 (EHD1 EH domain) with three peptides containing NPF (asparagine-proline-phenylalanine), DPF (aspartic acid-proline-phenylalanine), and GPF (glycine-proline-phenylalanine) motifs were deciphered at the atomic level. The binding affinities and the underlying structure basis were investigated.Molecular dynamics (MD) simulations were performed on EHD1 EH domain/peptide complexes for 60 ns using the GROMACS package. The binding free energies were calculated and decomposed by molecular mechanics/generalized Born surface area (MM/GBSA) method using the AMBER package. The alanine scanning was performed to evaluate the binding hot spot residues using FoldX software.The different binding affinities for the three peptides were affected dominantly by van der Waals interactions. Intermolecular hydrogen bonds provide the structural basis of contributions of van der Waals interactions of the flanking residues to the binding.van der Waals interactions should be the main consideration when we design peptide inhibitors of EHD1 EH domain with high affinities. The ability to form intermolecular hydrogen bonds with protein residues can be used as the factor for choosing the flanking residues.从结构和能量两个角度, 探究EHD1 蛋白中的Eps15 同源结构域与不同肽链之间形成的复合物之间的亲和力差异的原因, 为肽类抑制剂设计提供关键信息。通过分子动力学模拟的方法, 详细分析了三个复合物的结构差异。通过结合自由能计算及能量分解, 定量对比了三条肽链中各个残基对复合物形成的贡献, 确定了范德华相互作用以及侧面残基的氢键是影响亲和力大小的关键因素。用GROMACS 程序对EHD1 蛋白中的Eps15 同源结构域与肽链形成的三个复合物进行各60 纳秒的分子动力学模拟, 用AMBER 程序中的MM/GBSA 方法进行结合自由能计算和能量分解, 用FoldX 软件对三个复合物进行丙氨酸扫描实验。在对EHD1 蛋白中的Eps15 同源结构域进行高亲和力的肽类抑制剂设计时, 范德华相互作用应该成为主要考虑因素。与蛋白质形成氢键的能力是侧面残基选择的参考因素。

A copper-mediated C–S/N–S bond–forming reaction via C–H activation that uses elemental sulfur has been developed. The addition of TBAI was found to be crucial for the success of this transformation. The method is scalable, shows excellent functional group tolerance, and is compatible with heterocycle substrates, providing efficient and practical access to benzoisothiazolones. The direct diversification of the benzoisothiazolone products into a variety of sulfur-containing compounds is also demonstrated.

An efficient metal-free C–N bond forming reaction through cleavage of aryl C–O bond and amide C–N bond has been developed. This process represents a practical method for the facile construction of anilines with a broad substrate scope and wide functional group tolerance in moderate to excellent yields.

A novel tandem reductive amination/intermolecular nucleophilic aromatic substitution (SNAr) sequence has been established for the synthesis of amine containing pyrimidine in formation of one carbon-oxygen and one carbon-nitrogen bonds in a one-pot fashion. Treatment of aldehyde with arylamine, 2-methanesulfonyl-4,6-dimethoxypyrimidine and sodium borohydride provides good overall yield. The p-toluenesulfonic acid (PTSA) can be used as activator and is generally needed in the reaction. Dioxane is the preferred reaction solvent, but reactions can also be carried out in tetrahydrofuran (THF), MeCN, toluene and dichloromethane. The procedure is carried out effectively in the presence of K2CO3. The reaction proceeds smoothly with aromatic aldehydes and arylamines possessing electron-donating or -withdrawing groups. This method can be applied to the synthesis of the oilseed rape herbicide and is superior to the classical one in several aspects: cutting out several purification steps, minimizing solvent use and chemical waste, and saving time. Its advantages such as operational convenience, high-efficient synthesis, and starting material availability make it a desirable method for preparing amines with molecular diversity and biological activity.