cross-coupling reaction has been developed under mild electrolytic conditions. In this atom- and step-economical one-pot process, valuable 1,2,4-triazolo[4,3-a]pyridines and related heterocyclic compounds could be synthesized efficiently from commercially available aliphatic or (hetero)aromatic aldehydes and 2-hydrazinopyridines. Various functional groups are compatible with this metal- and oxidant-free
在温和的电解条件下已开发出无试剂的分子内脱氢C–N交叉偶联反应。在这种原子经济和一步经济的一锅法中,有价值的1,2,4-三唑并[4,3- a ]吡啶和相关的杂环化合物可以从可商购的脂族或(杂)芳族醛和2-肼基吡啶。各种官能团都与这种无金属和无氧化剂的方案兼容,可以轻松地以克为单位进行操作。这种新方法被应用于最畅销药物Xanax的合成和后期功能化,以在生物学相关的先导分子中产生化学多样性。
Palladium-Catalyzed Coupling of Aldehyde-Derived Hydrazones: Practical Synthesis of Triazolopyridines and Related Heterocycles
作者:Oliver R. Thiel、Michal M. Achmatowicz、Andreas Reichelt、Robert D. Larsen
DOI:10.1002/anie.201001999
日期:2010.11.2
The palladium‐catalyzed intermolecular coupling of aldehyde‐derived hydrazones with chloroazines, followed by oxidative cyclization under mild conditions afforded access to a broad variety of bicyclic heterocyclic scaffolds (see scheme) that have potential for use in drug discovery.
A facile and efficient approach to access 1,2,4‐triazolo[4,3‐a]pyridines and related heterocycles has been accomplished through condensation of readily available aryl hydrazines with corresponding aldehydes followed by iodine‐mediated oxidative cyclization. This transition‐metal‐free synthetic process is broadly applicable to a variety of aromatic, aliphatic, and α,β‐unsaturated aldehydes, and can
通过容易获得的芳基肼与相应的醛缩合,然后由碘介导的氧化环化反应,可以轻松而有效地获得1,2,4-三唑并[4,3- a ]吡啶和相关杂环。这种无过渡金属的合成方法广泛适用于各种芳香族,脂肪族和α,β-不饱和醛类,并且可以以克为单位方便地进行。
Base-Mediated Reaction of Hydrazones and Nitroolefins with a Reversed Regioselectivity: A Novel Synthesis of 1,3,4-Trisubstituted Pyrazoles
作者:Xiaohu Deng、Neelakandha S. Mani
DOI:10.1021/ol800200j
日期:2008.3.1
A regioselectivesynthesis of 1,3,4-tri- or 1,3,4,5-tetrasubstituted pyrazoles by the reaction of hydrazones with nitroolefins is described. Mediated with strong bases such as t-BuOK, the reaction exhibits a reversed, exclusive 1,3,4-regioselectivity. Subsequent quenching with strong acids such as TFA is essential to achieve good yields. A plausible stepwise cycloaddition reaction mechanism is proposed
Experimental and quantum chemical studies of the structural and spectral properties of novel diazenyl formazans
作者:Habibe Tezcan、Hülya Şenöz、Nesrin Tokay
DOI:10.1016/j.molstruc.2019.04.055
日期:2019.8
values of the synthesized compounds with PBE1PBE functional and 6-311G(2d,2p) basis set combination. The IR spectra of the novel formazans were calculated using DFT at PBE1PBE/6-311G(d,p) level of theory. The electronic absorptionspectra of the optimized structures were evaluated by TD-DFT method at PBE1PBE/6-311G(2d,2p) level of theory. The absorptionspectra of the synthesized diazenyl formazans