Regioselective Direct C–H Alkylation of NH Indoles and Pyrroles by a Palladium/Norbornene-Cocatalyzed Process
摘要:
Nitrogen-containing heterocycles, including 1H-indoles and electron-deficient 1H-pyrroles, undergo a palladium/norbornene-cocatalyzed regioselective alkylation at the C-H bond adjacent to the NH group. A primary alkyl halide is used as the electrophile and the reaction proceeds smoothly under mild conditions to give 2-alkyl-1H-indoles and 2-substituted or 2,3-disubstituted 5-alkyl-1H-pyrroles in good yields.
Palladium-Catalyzed Direct CH Alkylation of Electron-Deficient Pyrrole Derivatives
作者:Lei Jiao、Thorsten Bach
DOI:10.1002/anie.201301154
日期:2013.6.3
What looks like a Friedel–Crafts alkylation reaction of electron‐deficient pyrroles is actually a PdII‐catalyzed, norbornene‐mediated CH activation reaction, in which the alkylation of the pyrrole core occurs by reductive elimination. As well as ethyl‐1H‐pyrrole‐2‐carboxylate (see scheme), several other 2,3‐disubstituted pyrroles underwent the selective C5 alkylation in good yield.
表观和实际:什么样子缺电子吡咯弗里德尔-克拉夫茨烷基化反应实际上是钯II催化的,降冰片烯体介导C ħ活化反应,其中,所述吡咯核的烷基化通过还原消除发生。除1 H H-吡咯2-羧酸乙酯(参见方案)外,其他几种2,3-二取代的吡咯也进行了选择性C5烷基化,收率很高。
Regioselective Direct C–H Alkylation of NH Indoles and Pyrroles by a Palladium/Norbornene-Cocatalyzed Process
作者:Thorsten Bach、Lei Jiao
DOI:10.1055/s-0033-1338523
日期:——
Nitrogen-containing heterocycles, including 1H-indoles and electron-deficient 1H-pyrroles, undergo a palladium/norbornene-cocatalyzed regioselective alkylation at the C-H bond adjacent to the NH group. A primary alkyl halide is used as the electrophile and the reaction proceeds smoothly under mild conditions to give 2-alkyl-1H-indoles and 2-substituted or 2,3-disubstituted 5-alkyl-1H-pyrroles in good yields.