Copper-Catalyzed C(sp<sup>2</sup>)–H Difluoroalkylation of Aldehyde Derived Hydrazones with Diboron as Reductant
作者:Miaolin Ke、Qiuling Song
DOI:10.1021/acs.joc.6b00324
日期:2016.5.6
An efficient and general method for C(sp2)–Hdifluoroalkylation of aldehyde derived hydrazones via a CuII/B2pin2-catalyzed reaction between difluoroalkylbromides and hydrazones was developed. In this reaction, both aromatic and aliphatic difluoroalkylated aldehyde derived hydrazones could be achieved in good to excellent yields. For some heteroaromatic aldehyde derived hydrazones, two fluoroacetates
通过Cu II / B 2 pin 2催化的二氟烷基溴与的反应,开发了一种有效且通用的醛衍生的C(sp 2)-H二氟烷基化方法。在该反应中,芳族和脂族二氟烷基化醛衍生的azo均可以良好至优异的产率获得。对于某些杂芳族醛衍生的azo,可以将两种氟乙酸酯引入最终产物中。初步的机理研究表明,通过SET途径的二氟烷基自由基参与了反应。另外,催化二硼试剂在该转化中起着不可或缺的作用。
Direct Electrochemical Synthesis of
<scp>Sulfur‐Containing</scp>
Triazolium Inner Salts
The electrochemical thiocyanation/cyclization of aldehyde hydrazones was developed under external oxidant‐free and catalyst‐free conditions. In contrast to previous thiocyanation, this electrosynthetic approach enabled a cascade C—H thiocyanation/cyclization through a mild, direct electrolysis manner in an undivided cell without the additive of halogens and stoichiometric oxidants. In this protocol
An ammonium persulfate mediated thiocyanation reaction of aldehyde‐derived hydrazones that affords 5‐thioxo‐1,2,4‐triazoliuminnersalts has been developed. The operational simplicity, mild and metal‐free reaction conditions performed at ambient temperature, wide functional group tolerance, and scalability of the process are key features of this method.
A metal-free and cost-effective synthetic protocol for the trifluoromethylation of N,N-disubstituted hydrazones with Langlois’s reagent (CF3SO2Na) to afford the corresponding functionalized trifluoromethyl ketone hydrazones has been established. It is proposed that a radical/SET mechanism proceeding via a trifluoroalkyl radical may be involved in the reaction. Applications of the methodology in industry
已经建立了一种无金属且具有成本效益的合成方案,用于使用Langlois试剂(CF 3 SO 2 Na)对N,N-二取代进行三氟甲基化,以提供相应的官能化三氟甲基酮。建议通过三氟烷基自由基进行的自由基/ SET机理可能参与该反应。我们将发现该方法在工业中的应用,并将继续在我们的实验室中开发使用Langlois试剂进行三氟甲基化的新方法。