<i>N</i>-Heterocyclic Carbene Catalyzed Addition of Aldehydes to Diazo Compounds: Stereoselective Synthesis of <i>N</i>-Acylhydrazones
作者:Fábio M. F. Santos、João N. Rosa、Vânia André、M. Teresa Duarte、Luís F. Veiros、Pedro M. P. Gois
DOI:10.1021/ol400563w
日期:2013.4.5
stereoselective synthesis of N-acylhydrazones via an unprecedented N-heterocyclic carbene catalyzed addition of aldehydes to diazo compounds is presented. Enals exclusively afforded N-acylhydrazones, in yields up to 91%. The observed regioselectivity was traced back to the reaction of the vinylogous Breslow intermediate via the acyl anion pathway over competing homoenolate, enol, and acyl azolium pathways
提出了通过空前的N-杂环卡宾催化的醛加至重氮化合物的创新的N-酰基hydr的立体选择性合成。Enals独家提供了N-酰基hydr,产率高达91%。观察到的区域选择性可追溯到乙烯基类Breslow中间体通过酰基阴离子途径在竞争性同烯酸酯,烯醇和酰基偶氮途径上的反应。根据DFT计算研究了这种不寻常的反应曲线,结果表明该反应是在轨道控制下,而不是受电荷控制。