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。
A formal [3+2] cycloaddition reaction of <i>N</i>-methylimidazole as a masked hydrogen cyanide: access to 1,3-disubstitued-1<i>H</i>-1,2,4-triazoles
作者:Issa Yavari、Omid Khaledian
DOI:10.1039/d0cc01065k
日期:——
N-Methylimidazole (NMI) can act as a masked HCN in the synthesis of 1,3-disubstitued-1H-1,2,4-triazoles via a formal cycloaddition reaction of hydrazonoyl chloride with NMI. The product was proved to be formed via an initial nucleophilic substitution of hydrazonoyl chloride with NMI following cyclization and two sequential C–N bond cleavages.
N-甲基咪唑(NMI)可通过1,酰氯与NMI的正式环加成反应在合成1,3-二取代-1 H -1,2,4-三唑中充当掩蔽的HCN 。事实证明,该产物是通过环化反应和两次连续的C–N键裂解后,用NMI进行酰肼基氯的初始亲核取代而形成的。
Synthesis of Spirobidihydropyrazole through Double 1,3-Dipolar Cycloaddition of Nitrilimines with Allenoates
The double 1,3-dipolar cycloaddition of allenoates with nitrilimines has been achieved under mild reaction conditions, affording a variety of spirobidihydropyrazoles in moderate to excellent yields with excellent diastereoselectivities. The reaction diastereoselectively constructs double dihydropyrazole moieties and two chiral centers including a spiro carbon center.
Preparation, properties, and reductive alkylation of arylhydrazides
作者:Giancarlo Verardo、Nicoletta Toniutti、Angelo G Giumanini
DOI:10.1139/v98-125
日期:1998.8.1
1-Acyl-2-arylhydrazines (1), readily obtained in high yield from the condensation of arylhydrazines and the appropriate liquid carboxylic acid (2), underwent reductivealkylation with the same or d...