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 Triazolopyridine Synthesis: Synthesis of 7-Chloro-3-(2-Chlorophenyl)-1,2,4-Triazolo[4,3-a]Pyridine
摘要:
Chloramine-T is thermally unstable and heating of chloramines-T beyond the temperature disclosed in this procedure should not be conducted without further safety evaluation. Hydrazine should be handled in a fume hood as it is an animal carcinogen and has been identified it as a potential human carcinogen. In addition, anhydrous hydrazine is potentially explosive, especially in contact with metals, and should only be handled as its hydrate.
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.
Microwave-enhanced Efficient Synthesis of Some Polyfunctional Pyridazines
作者:M. Kumar Jangid、T. Yadav、A. K. Yadav
DOI:10.1002/jhet.1623
日期:2013.8
Microwave‐enhanced highly efficient protocol for the synthesis of polyfunctional pyridazines beginning from 3,6‐dichloropyridazine in environmentally benign ionic liquids have been developed. The products obtained were 3‐amino‐6‐chloropyridazine, 3,6‐diaminopyridazine, and 3‐chloro‐6‐methoxypyridazine. These derivatives were then be converted to a variety of polyfunctional pyridazine derivatives. The ionic liquids
An efficient synthesis of a series of 6-chloro-3-substituted-[1,2,4]triazolo[4,3-b]pyridazines is described via intramolecular oxidative cyclization of various 6-chloropyridazin-3-yl hydrazones with iodobenzene diacetate. The structures of the newly synthesized compounds were assigned on the basis of elemental analysis, IR, NMR (1H and 13C) and mass spectral data. All the thirty three compounds 3a-q
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。