The synthesis of N-alkyl-1H-1,2,4-triazoles from N,N-dialkylhydrazones and nitriles via formal [3+2] cycloaddition including the C-chlorination/nucleophilic addition/cyclisation/dealkylation sequence was developed. This sequential reaction utilising the in situ generation of hydrazonoyl chloride based on the ambiphilic reactivity of hydrazones afforded a variety of multi-substituted N-alkyl-triazoles
The reductive singleelectrontransfer (SET) umpolung amination of aldehyde-derived hydrazones has been developed through visible-light-promoted photoredox catalysis. The ideal transformation of hydrazones into the corresponding hydrazonamide through selective carbon–hydrogen (C–H) bond functionalization represents one of the most step- and atom-economical methods. This SET umpolung strategy features
Gold-Catalyzed Highly Selective Photoredox C(sp<sup>2</sup>
)−H Difluoroalkylation and Perfluoroalkylation of Hydrazones
作者:Jin Xie、Tuo Zhang、Fei Chen、Nina Mehrkens、Frank Rominger、Matthias Rudolph、A. Stephen K. Hashmi
DOI:10.1002/anie.201508622
日期:2016.2.18
hydrazones are highly functionalized, versatile molecules. A mild reduction of the coupling products can efficiently produce gem‐difluoromethylated β‐amino phosphonic acids and β‐amino acid derivatives. In mechanistic studies, a difluoroalkyl radical intermediate was detected by an EPR spin‐trappingexperiment, indicating that a gold‐catalyzed radical pathway is operating.
据报道,使用容易获得的R F -Br试剂,gold的金催化光氧化还原C(sp 2)-H二氟烷基化和hydr的全氟烷基化。所得的宝石二氟甲基化和全氟烷基化的azo是高度官能化的多用途分子。偶合产物的轻度减少可以有效地生产出宝石-二氟甲基化的β-氨基膦酸和β-氨基酸衍生物。在机理研究中,通过EPR自旋捕获实验检测到二氟烷基自由基中间体,表明金催化的自由基途径正在起作用。
Visible-Light Photoredox-Catalyzed C−H Difluoroalkylation of Hydrazones through an Aminyl Radical/Polar Mechanism
products, and one‐pot syntheses. Mechanistic analyses and theoretical calculations indicate that this reaction is enabled by a novel aminylradical/polar crossover mechanism, with the aminylradical being oxidized into the corresponding aminyl cation through a single electrontransfer (SET) process.
Solvent-Free Conversion of N,N-Dimethylhydrazones to Nitriles Under Microwave Irradiation
作者:T. Ramalingam、B. V. Subba Reddy、R. Srinivas、J. S. Yadav
DOI:10.1080/00397910008087080
日期:2000.12.1
Abstract A variety of aldehyde N,N-dimethylhydrazones are rapidly converted into the corresponding nitriles using oxone supported on wet Al2O3 under microwave irradiation in dry media.