Medicinal and Process Chemistry Division, CSIR-Central Drug Research Institute, Lucknow, 226031, India.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
Chem Rec. 2020 Nov;20(11):1394-1408. doi: 10.1002/tcr.202000091. Epub 2020 Sep 28.
Azaheterocycles are one of the most prevalent classes of compounds present in numerous bioactive compounds, natural products, and agrochemicals, and undoubtedly, new methods to access them are always in high demand. Among the methods available, the 1,3-dipolar cycloaddition reactions involving diazo compounds are particularly attractive because of their ability to rapidly construct densely functionalized azaheterocycles in a regioselective manner. In this context, the Bestmann-Ohira reagent has become a well-known reagent for the 1,3-dipolar cycloaddition reactions to produce phosphonylated heterocycles, besides its widespread use as a homologating agent for the conversion of aldehydes to alkynes. This account details our efforts toward broadening the synthetic utility of the Bestmann-Ohira reagent and related compounds for the preparation of azaheterocycles such as pyrazoles, spirooxindoles, triazoles, triazolines, and spiropyrazolines, emphasizing on domino multicomponent reactions employing readily available feedstock reagents.
氮杂环化合物是存在于许多生物活性化合物、天然产物和农用化学品中的最常见化合物类别之一，毫无疑问，新的获取方法总是有很高的需求。在现有的方法中，涉及重氮化合物的 1,3-偶极环加成反应因其能够以区域选择性方式快速构建高度官能化的氮杂环化合物而特别吸引人。在这种情况下，Bestmann-Ohira 试剂已成为用于 1,3-偶极环加成反应以生成膦酰化杂环化合物的知名试剂，除了其作为将醛转化为炔烃的同系化试剂的广泛应用外。本说明详细介绍了我们为扩大 Bestmann-Ohira 试剂和相关化合物在制备氮杂环化合物（如吡唑、螺噁吲哚、三唑、三唑啉和螺吡唑啉）方面的合成实用性而做出的努力，重点强调了使用易得的原料试剂进行的多米诺多组分反应。
