Saikia Lakhinath, Baruah Jejiron Maheswari, Thakur Ashim Jyoti
Department of Chemical Sciences, Central University, Tezpur, Napaam, Tezpur 784028, Assam, India.
Org Med Chem Lett. 2011 Oct 4;1(1):12. doi: 10.1186/2191-2858-1-12.
Synthesis of oximes is an important reaction in organic chemistry, because these versatile oximes are used for protection, purification, and characterization of carbonyl compounds. Nitriles, amides via Beckmann rearrangement, nitro compounds, nitrones, amines, and azaheterocycles can be synthesised from oximes. They also find applications for selective α-activation. In inorganic chemistry, oximes act as a versatile ligand.Several procedures for the preparation of oximes exist, but, most of them have not addressed the green chemistry issue. They are associated with generation of pollutants, requirement of high reaction temperature, low yields, lack of a generalized procedure, etc. Hence, there is a demand for developing an efficient, convenient, and non-polluting or less polluting alternative method for the preparation of oximes. In this context, bismuth compounds are very useful as they are cheap in general, commercially available, air stable crystalline solids, safe, and non-toxic, hence easy to handle.
Carbonyl compounds (aliphatic, heterocyclic, and aromatic) were converted into the corresponding oximes in excellent yields by simply grinding the reactants at room temperature without using any solvent in the presence of Bi2O3. Most importantly, this method minimizes waste disposal problems, provides a simple yet efficient example of unconventional methodology and requires short time.
We have developed a novel, quick, environmentally safe, and clean synthesis of aldoximes and ketoximes under solvent-free grinding condition.
肟的合成是有机化学中的一个重要反应，因为这些多功能的肟可用于羰基化合物的保护、纯化和表征。肟可用于合成腈、通过贝克曼重排合成酰胺、硝基化合物、硝酮、胺和氮杂环。它们还可用于选择性α-活化。在无机化学中，肟是一种多功能配体。
存在多种制备肟的方法，但大多数方法都未解决绿色化学问题。它们与污染物的产生、高反应温度的要求、低产率、缺乏通用方法等有关。因此，需要开发一种高效、方便且无污染或污染较小的肟制备替代方法。在这种情况下，铋化合物非常有用，因为它们通常价格便宜、可商购、空气稳定的结晶固体、安全且无毒，因此易于处理。
在室温下，在Bi2O3存在下，通过简单研磨反应物而不使用任何溶剂，羰基化合物（脂肪族、杂环和芳香族）以优异的产率转化为相应的肟。最重要的是，该方法最大限度地减少了废物处理问题，提供了一个简单而有效的非传统方法示例，且所需时间短。
我们开发了一种在无溶剂研磨条件下新颖、快速、环境安全且清洁的醛肟和酮肟合成方法。
