A novel annulation reaction of N-(het)aroyldiazenes and isothiocyanates has been established. This transformation involves a sequential cyclization and desulfurization/intramolecular rearrangement to produce 2-imino-1,3,4-oxadiazolines. The less-stable N-(het)aroyldiazenes can be conveniently generated in situ by I2-mediated oxidation of hydrazides, which allows a one-pot synthesis of the products
Synthesis of 2-Imino-1,3,4-thiadiazoles from Hydrazides and Isothiocyanates via Sequential Oxidation and P(NMe<sub>2</sub>)<sub>3</sub>-Mediated Annulation Reactions
N-acyldiazenes with isothiocyanates, producing 2-imino-1,3,4-thiadiazoles, is reported. This reaction proceeds well with crude N-acyldiazenes derived from the oxidation of hydrazides by iodine and permits the sequential synthesis of products directly from hydrazides without purification of the less stable N-acyldiazene intermediates. The reaction does not require transition metals and is a simple, scalable operation
The present application relates to the use of heterocyclic compounds for controlling animal pests including arthropods, insects and nematodes, to novel heterocyclic compounds, to processes for their preparation and to intermediates for preparing the heterocyclic compounds.
A nickel-promoted cascadeannulation reaction for the facile synthesis of 3H-1,2,4-triazol-3-ones from readily available hydrazonoyl chlorides and sodium cyanate has been developed. The transformation occurs through a cascade nickel-promoted intermolecular nucleophilic addition–elimination process, intramolecular nucleophilic addition, and a hydrogen-transfer sequence. The method has been successfully
已经开发了镍促进的级联环化反应,用于从容易获得的酰肼基氯和氰酸钠容易地合成3 H -1,2,4-三唑-3-酮。通过级联镍促进的分子间亲核加成-消除过程,分子内亲核加成和氢转移序列进行转化。该方法已成功应用于血管紧张素II拮抗剂的核心骨架的构建。
Palladium-Catalyzed Cascade Carbonylative Synthesis of 1,2,4-Triazol-3-ones from Hydrazonoyl Chlorides and NaN<sub>3</sub>
A palladium-catalyzed three-component carbonylative reaction for the synthesis of 3H-1,2,4-triazol-3-ones from hydrazonoyl chlorides and NaN3 has been achieved. The reaction presumably proceeds through a cascadecarbonylation, acyl azide formation, Curtius rearrangement, and intramolecular nucleophilic addition sequence. A wide variety of structurally diverse 3H-1,2,4-triazol-3-ones were constructed
已实现了钯催化的三组分羰基化反应,该反应可从酰氯和NaN 3合成3 H -1,2,4-三唑-3-酮。该反应大概通过级联羰基化,酰基叠氮化物形成,Curtius重排和分子内亲核加成序列进行。以中等至优异的产率构建了各种结构多样的3 H -1,2,4-三唑-3-酮。1,2,3,5-三甲酸三苯酯(TFBen)被用作固体和方便的一氧化碳替代物。