A one-pot pseudo nine-component isocyanide-based reaction: synthesis of a new class of zinc 1,5-disubstituted 1H-tetrazol-5-yl coordination complexes

A novel one-pot pseudo nine-component synthesis of zinc 1,5-disubstituted 1H-tetrazol-5-yl coordination complexes in good yields starting from simple and readily available substrates, including a 1,3-dicarbonyl compound, an isocyanide, N,N-dimethylformamide dimethyl acetal, sodium azide, and zinc chloride in methanol at ambient temperature, is described.     

N-Heterocycle (tetrazole)-stabilized pseudocyclic λ3-iodane: Synthesis and reactivity

An N-heterocycle (tetrazole)-stabilized pseudocyclic λ³-iodane was synthesized and its thermal stability and redox activity were studied. Simultaneous thermogravimetric analysis and differential scanning calorimetry revealed that the polyvalent iodine compound started to degrade at 127 °C and showed a notable exothermic decomposition peak at 147 °C, which was markedly more pronounced than the parent tetrazole with monovalent iodine. The reduction potential was determined by cyclic voltammetry to be ?0.38 V vs AgNO₃|Ag in dimethyl sulfoxide at a scan rate of 0.02 V/s. The oxidative power of the polyvalent iodine compound was demonstrated by conducting oxidation of thioanisole to sulfoxide and oxidative dimerization of thiobenzamide to 3,5-diphenyl-1,2,4-thiadiazole.     

双核茂铁四氮唑的合成及对高氯酸铵热分解的催化作用

首先以二茂铁为原料合成丙基桥联的双聚二茂铁(DFP), 经甲酰化得到丙基桥联的双聚二茂铁甲醛(DFP-CHO, 1), 再与NH₂OH·5HCl进行缩合反应得到双核二茂铁肟(2), 然后脱水得到丙基桥联双聚二茂铁甲腈(3), 最后在(n-C₄H₉)₃SnCl 的催化作用下与NaN₃进行[2+3]环加成反应, 生成目标产物丙基桥联双聚二茂铁四唑(4); 通过¹H NMR, FTIR和ESI-MS对目标产物的结构进行了表征. 利用差示扫描量热分析(DSC)和热重(TG)分析研究了这2个双聚二茂铁氮杂衍生物的燃速催化性能, 结果表明, 通过添加质量分数为5%的丙基桥联双聚二茂铁氮杂化合物3和4均使高氯酸铵(AP)的热分解温度降至100℃左右.     

Tetrazole Diversification of Amino Acids and Peptides via Silver-Catalyzed Intermolecular Cycloaddition with Aryldiazonium Salts

Selective structural modification of amino acids and peptides is a central strategy in organic chemistry, chemical biology but also in pharmacology and material science. In this context, the formation of tetrazole rings, known to possess significant therapeutic properties, would expand the chemical space of unnatural amino acids but has received less attention. In this study, we demonstrated that the classic unimolecular Wolff rearrangement of α-amino acid-derived diazoketones could be replaced by a faster intermolecular cycloaddition reaction with aryldiazonium salts under identical practical conditions. This strategy provides an efficient synthetic platform that could transform proteinogenic α-amino acids into a plethora of unprecedented tetrazole-decorated amino acid derivatives with preservation of the stereocenters. Density functional theory studies shed some light on the reaction mechanism and provided information regarding the origins of the chemo- and regioselectivity. Furthermore, this diazo-cycloaddition protocol was applied to construct tetrazole-modified peptidomimetics and drug-like amino acid derivatives.