Oligosubstituted Pyrroles Directly from Substituted Methyl Isocyanides and Acetylenes
作者:Alexander V. Lygin、Oleg V. Larionov、Vadim S. Korotkov、Armin de Meijere
DOI:10.1002/chem.200801395
日期:2009.1
methyl isocyanides 1 onto the triple bond of electron‐deficient acetylenes 2 represents a direct and convenient approach to oligosubstituted pyrroles 3. The scope and limitations of this reaction (24 examples, 25–97 % yield) are reported along with an optimization of the reaction conditions and a rationalization of the mechanism. In addition, a related newly developed CuI‐mediated synthesis of 2,3‐disubstituted
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。